How to make laser. How to make a powerful laser

Many of you have probably heard what to make laser pointer or even a cutting beam is quite possible at home, using simple improvised means, but few people know how to make a laser on their own. Before you start working on it, be sure to familiarize yourself with the safety precautions.

Safety rules when working with laser

Improper use of the beam, especially at high power, can lead to property damage, as well as serious harm to your health or the health of bystanders. Therefore, before testing your own made copy, remember the following rules:

Make sure there are no animals or children in the testing room.
Never point the beam at animals or people.
Wear safety glasses, such as welding glasses.
Remember that even a reflected beam can damage your vision. Never shine a laser into your eyes.
Do not use the laser to ignite objects while indoors.

The simplest laser from a computer mouse

If you need a laser just for fun, it’s enough to know how to make a laser at home from a mouse. Its power will be quite insignificant, but it will not be difficult to manufacture. All you need is a computer mouse, a small soldering iron, batteries, wires and a shutdown switch.

First, the mouse must be disassembled. It is important not to break them out, but to carefully unscrew and remove them in order. First the upper casing, followed by the lower casing. Next, using a soldering iron, you need to remove the mouse laser from the board and solder new wires to it. Now all that remains is to connect them to the shutdown switch and connect the wires to the battery contacts. Batteries can be used of any type: both finger batteries and so-called pancakes.

Thus, the simplest laser is ready.

If a weak beam is not enough for you, and you are interested in how to make a laser at home using improvised means with sufficiently high power, then you should try a more the hard way its production, using a DVD-RW drive.

To work you will need:

DVD-RW drive (write speed must be at least 16x);
AAA battery, 3 pcs.;
resistor (from two to five ohms);
collimator (can be replaced with a part from a cheap Chinese laser pointer);
capacitors 100 pF and 100 mF;
LED lamp made of steel;
wires and soldering iron.

Work progress:

The first thing we need is a laser diode. It is located in the DVD-RW drive carriage. It has a larger heatsink than a regular infrared diode. But be careful, this part is very fragile. While the diode is not installed, it is best to wrap its lead with wire, since it is too sensitive to static voltage. Please pay Special attention for polarity. If the power supply is incorrect, the diode will immediately fail.

Connect the parts according to the following scheme: battery, on/off button, resistor, capacitors, laser diode. Once the functionality of the design has been verified, all that remains is to come up with a convenient housing for the laser. For these purposes, a steel body from a regular flashlight is quite suitable. Don’t forget also about the collimator, because it is the one that turns the radiation into a thin beam.

Now that you know how to make a laser at home, do not forget to follow safety precautions, store it in a special case and do not carry it with you, as law enforcement agencies may file complaints against you in this regard.

Watch the video: Laser from a DVD drive at home and with your own hands

Laser cutter - unique device, which is useful to have in everyone's garage modern man. Making a laser for cutting metal with your own hands is not difficult, the main thing is to follow simple rules. The power of such a device will be small, but there are ways to increase it using available devices. The functionality of a production machine that can do anything without embellishment cannot be achieved with a homemade product. But for household chores, this unit will come in handy. Let's look at how to build it.

How to make a laser cutter in the garage

Everything is ingeniously simple, so to create such equipment, which is capable of cutting out the most beautiful patterns in durable steel, can be made from ordinary scrap materials. To make this you will definitely need an old laser pointer. In addition, you should stock up on:

A flashlight powered by rechargeable batteries.
An old DVD-ROM, from which we will need to remove the matrix with a laser drive.
Soldering iron and set of screwdrivers.

The first step will be to disassemble the drive of the old computer floppy drive. From there we should remove the device. Be careful not to damage the device itself. The drive of the disk drive must be a writer, and not just a reader, the point is in the structure of the device matrix. We won’t go into details now, but just use modern non-working models.

After this, you will definitely need to remove the red diode, which burns the disk while recording information to it. Just took a soldering iron and soldered the fastenings of this diode. Just don't throw it away under any circumstances. This is a sensitive element that can quickly deteriorate if damaged.

When assembling the laser cutter itself, consider the following:

Where is it better to install a red diode?
How will the elements of the entire system be powered?
How the flow of electric current will be distributed in the part.

Remember! The diode that will perform the burning requires much more electricity than the elements of the pointer.

This dilemma is easily resolved. The diode from the pointer is replaced by a red light from the drive. You should disassemble the pointer with the same care as the disk drive; damage to the connectors and holders will ruin your future with your own hands. Once you have done this, you can begin making the homemade case.

To do this you will need a flashlight and rechargeable batteries that will power laser cutter. Thanks to the flashlight, you will get a convenient and compact item that does not take up much space in your home. The key point equipment of such a housing is to choose the correct polarity. The protective glass from the former flashlight is removed so that it does not become an obstacle to the directed beam.

The next step is to power the diode itself. To do this, you need to connect it to the battery charging, observing the polarity. Finally, check:

Reliable fixation of the device in clamps and clamps;
Device polarity;
Beam direction.

Fix any inaccuracies, and when everything is ready, you can congratulate yourself on a successfully completed job. The cutter is ready to use. The only thing you need to remember is that its power is much less than the power of its production counterpart, so it cannot handle too thick metal.

Carefully! The power of the device is enough to harm your health, so be careful when operating and try not to put your fingers under the beam.

Strengthening a homemade installation

To enhance the power and density of the beam, which is the main cutting element, you should prepare:

2 “conders” for 100 pF and mF;
Resistance 2-5 ohms;
3 rechargeable batteries;
Collimator.

The installation that you have already assembled can be strengthened to get enough power at home for any work with metal. When working on gain, remember that plugging your cutter directly into an outlet will be suicide for it, so you should make sure that the current first gets to the capacitors, and then goes to the batteries.

By adding resistors you can increase the power of your installation. To further increase the efficiency of your device, use a collimator that is mounted to focus the beam. This model is sold in any electrician store, and the cost ranges from 200 to 600 rubles, so it’s not difficult to buy it.

Then the assembly circuit is carried out in the same way as discussed above, only you need to wind an aluminum wire around the diode to remove static. After this, you have to measure the current strength, for which you take a multimeter. Both ends of the device are connected to the remaining diode and measured. Depending on your needs, you can adjust the readings from 300 mA to 500 mA.

Once the current calibration is completed, you can move on to aesthetically decorating your cutter. An old steel LED flashlight will do just fine for the case. It is compact and fits in your pocket. To prevent the lens from getting dirty, be sure to get a cover.

The finished cutter should be stored in a box or case. Dust or moisture should not get there, otherwise the device will be damaged.

What is the difference between ready-made models

The cost is main reason, why many craftsmen resort to making a laser cutter with their own hands. And the principle of operation is as follows:

Thanks to the creation of a directed laser beam, the metal is exposed
The powerful radiation causes the material to evaporate and escape under the force of the flow.
As a result, thanks to the small diameter of the laser beam, a high-quality cut of the workpiece is obtained.

The cutting depth will depend on the power of the components. If factory models are equipped with high-quality materials that provide sufficient depth. Then homemade models can handle cutting 1-3 cm.

Thanks to such laser systems, you can make unique patterns in the fence of a private house, components for decorating gates or fences. There are only 3 types of cutters:

Solid state. The operating principle is based on the use of special types of glass or crystals of LED equipment. These are inexpensive production plants which are used in production.
Fiber. Thanks to the use optical fiber You can get a powerful flow and sufficient cutting depth. They are analogues of solid-state models, but due to their capabilities and performance characteristics they are better than them. But also more expensive.
Gas. From the name it is clear that gas is used for operation. It can be nitrogen, helium, carbon dioxide. The efficiency of such devices is 20% higher than all previous ones. They are used for cutting and welding polymers, rubber, glass and even metal with a very high level of thermal conductivity.

In everyday life without special costs You can only get a solid-state laser cutter, but its power with proper amplification, which was discussed above, is enough to perform household work. Now you have knowledge about making such a device, and then just act and try.

Do you have experience in developing a DIY metal laser cutter? Share with readers by leaving a comment under this article!

Who in childhood did not dream of laser? Some men still dream. Conventional laser pointers with low power are no longer relevant for a long time, since their power leaves much to be desired. There are 2 options left: buy an expensive laser or make it at home using improvised materials.

From an old or broken DVD drive
From computer mouse and a flashlight
From a kit of parts purchased at an electronics store

How to make a laser at home from an old oneDVDdrive

Find a non-working or unwanted DVD drive that has a recording speed greater than 16x and outputs more than 160mW of power. Why can't you take a recordable CD, you ask? The fact is that its diode emits infrared light, invisible to the human eye.
Remove the laser head from the drive. To access the “internals”, unscrew the screws located on the bottom of the drive and remove the laser head, which is also held in place by screws. It may be in a shell or under a transparent window, or maybe even outside. The most difficult thing is to remove the diode itself from it. Caution: The diode is very sensitive to static electricity.
Get a lens, without which it will be impossible to use the diode. You can use a regular magnifying glass, but then you will have to twist and adjust it every time. Or you can purchase another diode included with the lens, and then replace it with the diode removed from the drive.
Next you will have to buy or assemble a circuit to power the diode and assemble the structure together. In a DVD drive diode, the center pin acts as the negative terminal.
Connect a suitable power source and focus the lens. All that remains is to find a suitable container for the laser. You can use a metal flashlight of suitable size for these purposes.
We recommend watching this video, where everything is shown in great detail:

How to make a laser from a computer mouse

The power of a laser made from a computer mouse will be much less than the power of a laser made using the previous method. The manufacturing procedure is not very different.

First, find an old or unnecessary mouse with visible laser any color. Mice with an invisible glow are not suitable for obvious reasons.
Next, carefully disassemble it. Inside you will notice a laser that will have to be soldered using a soldering iron.
Now repeat steps 3-5 from the instructions above. The difference between such lasers, we repeat, is only in power.

Each of us held a laser pointer in our hands. Despite the decorative use, it contains a real laser, assembled on the basis of a semiconductor diode. The same elements are installed on laser levels and.

The next popular product assembled on a semiconductor is your computer's DVD burner drive. It contains a more powerful laser diode with thermal destructive power.

This allows you to burn a layer of the disc, depositing tracks with digital information on it.

How does a semiconductor laser work?

Devices of this type are inexpensive to produce and the design is quite widespread. The principle of laser (semiconductor) diodes is based on the use of a classic p-n junction. This transition works the same as in conventional LEDs.

The difference is in the organization of radiation: LEDs emit “spontaneously”, while laser diodes emit “forced”.

The general principle of the formation of the so-called “population” of quantum radiation is fulfilled without mirrors. The edges of the crystal are mechanically chipped, providing a refractive effect at the ends, akin to a mirror surface.

To obtain different types of radiation, a “homojunction” can be used, when both semiconductors are the same, or a “heterojunction”, with different materials transition.

The laser diode itself is an accessible radio component. You can buy it in stores that sell radio components, or you can extract it from an old DVD-R (DVD-RW) drive.

Important! Even the simple laser used in light pointers can cause serious damage to the retina of the eye.

More powerful installations, with a burning beam, can deprive vision or cause burns skin. Therefore, use extreme caution when working with such devices.

With such a diode at your disposal, you can easily make a powerful laser with your own hands. In fact, the product may be completely free, or it will cost you a ridiculous amount of money.

DIY laser from a DVD drive

First, you need to get the drive itself. It can be removed from an old computer or purchased at a flea market for a nominal cost.

Information: The higher the declared recording speed, the more powerful the burning laser is used in the drive.

Having removed the case and disconnected the control cables, we dismantle the writing head along with the carriage.

To remove the laser diode:

We connect the legs of the diode to each other using a wire (bypass). During dismantling, static electricity may accumulate and the diode may fail.
Delete aluminum radiator. It is quite fragile, has a mount that is structurally “tailored” for a specific DVD drive, and is not needed for further operation. Just cut the radiator with wire cutters (without damaging the diode)
We unsolder the diode and free the legs from the shunt.

The element looks like this:

The next important element is the laser power circuit. You won't be able to use the power supply from the DVD drive. It is integrated into the general control circuit; it is technically impossible to remove it from there. Therefore, we make the power supply circuit ourselves.

There is a temptation to just connect 5 volts with a limiting resistor and not bother with the circuit. This is the wrong approach, since any LEDs (including laser ones) are powered not by voltage, but by current. Accordingly, a current stabilizer is needed. The most affordable option is to use the LM317 chip.

The output resistor R1 is selected in accordance with the supply current of the laser diode. In this circuit, the current should correspond to 200 mA.

You can assemble a laser with your own hands in a housing from a light pointer, or you can purchase a ready-made module for a laser in electronics stores or on Chinese websites (for example, Ali Express).

The advantage of this solution is that you get a ready-made adjustable lens included. The power supply circuit (driver) easily fits into the module housing.

If you decide to make the case yourself, from some metal tube, you can use a standard lens from the same DVD drive. You just need to come up with a mounting method and the ability to adjust the focus.

Important! Focusing the beam is necessary for any design. It can be parallel (if you need range) or cone-shaped (if you need to get a concentrated thermal spot).

The lens complete with a control device is called a collimator.

To properly connect the laser from the DVD drive, you need a contact diagram. You can track the negative and positive wires by markings on the circuit board. This must be done before dismantling the diode. If this is not possible, use the standard hint:

The negative contact has an electrical connection with the diode body. Finding it won't be difficult. Regarding the minus located at the bottom, the positive contact will be on the right.

If you have a three-pin laser diode (and most do), there will be either an unused pin on the left or a photodiode connection. This happens if both the burning and reading elements are located in the same housing.

The main body is selected based on the size of the batteries or accumulators that you plan to use. Carefully attach your homemade laser module into it, and the device is ready for use.

With the help of such a tool you can do engraving, wood burning, and cutting fusible materials (fabric, cardboard, felt, polystyrene foam, etc.).

How to make an even more powerful laser?

If you need a cutter for wood or plastic, the power of a standard diode from a DVD drive is not enough. You will either need a ready-made diode with a power of 500-800 mW, or you will have to spend a lot of time searching for suitable DVD drives. Some LG and SONY models use laser diodes with a power of 250-300 mW.

The main thing is that such technologies are available for self-production.

Step-by-step video instructions on how to make a laser from a DVD drive with your own hands

Hello ladies and gentlemen. Today I am opening a series of articles devoted to high-power lasers, because Habrasearch says that people are looking for such articles. I want to tell you how you can make a fairly powerful laser at home, and also teach you how to use this power not just for the sake of “shine on the clouds.”

Warning!

The article describes the manufacture of a high-power laser ( 300mW ~ power 500 Chinese pointers), which can harm your health and the health of others! Be extremely careful! Use special safety glasses and do not direct the laser beam at people or animals!

Let's find out.

On Habré, articles about portable Dragon Lasers, such as Hulk, appeared only a couple of times. In this article I will tell you how you can make a laser that is not inferior in power to most models sold in this store.

Let's cook.

First you need to prepare all the components:
- a non-working (or working) DVD-RW drive with a write speed of 16x or higher;
- capacitors 100 pF and 100 mF;
- resistor 2-5 Ohm;
- three AAA batteries;
- soldering iron and wires;
- collimator (or Chinese pointer);
- steel LED lamp.

This is the minimum required for making a simple driver model. The driver is, in fact, a board that will output our laser diode to the required power. You should not connect the power source directly to the laser diode - it will break down. The laser diode must be powered with current, not voltage.

A collimator is, in fact, a module with a lens that reduces all radiation into a narrow beam. Ready-made collimators can be purchased at radio stores. These already have comfortable spot for installing a laser diode, and the cost is 200-500 rubles.

You can also use a collimator from a Chinese pointer, however, the laser diode will be difficult to attach, and the collimator body itself will most likely be made of metallized plastic. This means our diode will not cool well. But this is also possible. This option can be found at the end of the article.

Let's do it.

First you need to get the laser diode itself. This is a very fragile and small part of our DVD-RW drive - be careful. A powerful red laser diode is located in the carriage of our drive. You can distinguish it from a weak one by its larger radiator than that of a conventional IR diode.

It is recommended to use an antistatic wrist strap as the laser diode is very sensitive to static voltage. If there is no bracelet, then you can wrap the diode leads with thin wire while it waits for installation in the case.

According to this scheme, you need to solder the driver.

Don't mix up the polarity! The laser diode will also fail instantly if the polarity of the supplied power is incorrect.

The diagram shows a 200 mF capacitor, however, for portability, 50-100 mF is quite enough.

Let's try.

Before installing the laser diode and assembling everything into the housing, check the functionality of the driver. Connect another laser diode (non-working or the second one from the drive) and measure the current with a multimeter. Depending on the speed characteristics, the current strength must be chosen correctly. For 16 models, 300-350mA is quite suitable. For the fastest 22x, you can even supply 500mA, but with a completely different driver, the manufacture of which I plan to describe in another article.

Looks terrible, but it works!

Aesthetics.

A laser assembled by weight can only be boasted of in front of the same crazy techno-maniacs, but for beauty and convenience it is better to assemble it in a convenient case. Here it’s better to choose for yourself how you like it. I mounted the entire circuit into a regular LED flashlight. Its dimensions do not exceed 10x4cm. However, I do not recommend carrying it with you: you never know what claims the relevant authorities may make. It is better to store it in a special case so that the sensitive lens does not become dusty.

This is an option with minimal costs- a collimator from a Chinese pointer is used:

Using a factory-made module will allow you to get the following results:

The laser beam is visible in the evening:

And, of course, in the dark:

Maybe.

Yes, in the following articles I want to tell and show how such lasers can be used. How to make much more powerful specimens, capable of cutting metal and wood, and not just lighting matches and melting plastic. How to make holograms and scan objects to create 3D Studio Max models. How to make powerful green or blue lasers. The scope of application of lasers is quite wide, and one article cannot do it here.

We need to remember.

Don't forget about safety precautions! Lasers are not a toy! Take care of your eyes!

Turn your MiniMag laser pointer into a cutting laser with a DVD burner emitter! This 245mW laser is very powerful and is the perfect size for the MiniMag! Watch the attached video. PLEASE NOTE: you can't do this yourself WITH ALL CDRW-DVD cutter diodes!

Warning: CAUTION! As you know, lasers can be dangerous. Never point the pointer at a living creature! This is not a toy and cannot be treated like a regular laser pointer. In other words, don't use it for presentations or playing with animals, and don't let children play with it. This device should be in the hands of a reasonable person who understands and is responsible for the potential hazards posed by the pointer.

Step 1 - What you will need...

You will need the following:

1. 16X DVD cutter. I used an LG drive.

step 2 - And...

2. The MiniMag laser pointer can be purchased at any store selling hardware, sports or household goods.

3. AixiZ case with AixiZ for $4.5

4. Small screwdrivers (hourly), a utility knife, metal scissors, a drill, a round file and other small tools.

Step 3 - Remove the laser diode from the DVD drive

Remove the screws from the DVD drive and remove the cover. Below it you will find the laser carriage drive assembly.

Step 4 - Take out the laser diode...

Although DVD drives are different, each has two guides along which the laser carriage moves. Remove the screws, release the guides and remove the carriage. Disconnect the connectors and ribbon cables.

Step 5 - Continue to disassemble...

Having removed the carriage from the drive, begin disassembling the device by unscrewing the screws. There will be a lot of small screws, so be patient. Disconnect the cables from the carriage. There may be two diodes, one for reading the disc (infrared diode) and the actual red diode, which is used for burning. You need a second one. A printed circuit board is attached to the red diode using three screws. Use a soldering iron to CAREFULLY remove the 3 screws. You can test the diode using two AA batteries, taking into account the polarity. You will have to remove the diode from the housing, which will vary depending on the drive. The laser diode is a very fragile part, so be extremely careful.

step 6 - Laser diode in a new guise!

This is what your diode should look like after being “released”.

step 7 - Preparing the AixiZ body...

Remove the sticker from the AixiZ body and unscrew the body into upper and lower parts. Inside the top there is a laser diode (5 mW), which we will replace. I used an X-Acto knife and after two light strikes, the original diode came out. In fact, such actions can damage the diode, but I have managed to avoid this before. Using a very small screwdriver, I knocked out the emitter.

step 8 - Assembling the body...

I used some hot glue and carefully installed the new DVD diode into the AixiZ case. Using pliers, I SLOWLY pressed the edges of the diode towards the body until it was flush.

step 9 - Install it in MiniMag

Once the two conductors are soldered to the positive and negative terminals of the diode, you can install the device in the MiniMag. After disassembling the MiniMag (remove the cap, reflector, lens and emitter), you will need to enlarge the MiniMag reflector using a round file or drill, or both.

step 10 - Last step

Remove the batteries from the MiniMag and after checking the polarity, carefully place the DVD laser housing on the top of the MiniMag where the emitter was previously located. Assemble the top of the MiniMag housing and attach the reflector. You won't need the plastic MiniMag lens.

Make sure the polarity of the diode is correct before you install it and connect power! You may need to shorten the wires and adjust the beam focus.

step 11 - Measure seven times

Replace the batteries (AA) and screw on the top of the MiniMag, including your new laser pointer! Attention!! Laser diodes are dangerous, so do not point the beam at people or animals.

]Book

Name
Author: team
Format: Mixed
Size: 10.31 MB
Quality: Excellent
Language: Russian
The year of publishing: 2008

Like in a science fiction movie - you pull the trigger and the ball explodes! Learn how to make a laser like this!
You can make such a laser yourself, at home, from a DVD drive - not necessarily a working one. There is nothing complicated!
Lights matches, eats air balloons, cuts bags and tape and much more
You can also use it to burst a balloon or a light bulb in the house opposite.
The archive contains a video of the laser in action and detailed Russian instructions with pictures on how to make it!

The next popular product assembled on a semiconductor is your computer's DVD burner drive. It contains a more powerful laser diode with thermal destructive power.

This allows you to burn a layer of the disc, depositing tracks with digital information on it.

How does a semiconductor laser work?

The difference is in the organization of radiation: LEDs emit “spontaneously”, while laser diodes emit “forced”.

To obtain different types of radiation, a “homojunction” can be used, when both semiconductors are the same, or a “heterojunction”, with different transition materials.

The laser diode itself is an accessible radio component. You can buy it in stores that sell radio components, or you can extract it from an old DVD-R (DVD-RW) drive.

Important! Even the simple laser used in light pointers can cause serious damage to the retina of the eye.

More powerful installations, with a burning beam, can deprive vision or cause burns to the skin. Therefore, use extreme caution when working with such devices.

With such a diode at your disposal, you can easily make a powerful laser with your own hands. In fact, the product may be completely free, or it will cost you a ridiculous amount of money.

DIY laser from a DVD drive

First, you need to get the drive itself. It can be removed from an old computer or purchased at a flea market for a nominal cost.

Information: The higher the declared recording speed, the more powerful the burning laser is used in the drive.

Having removed the case and disconnected the control cables, we dismantle the writing head along with the carriage.

To remove the laser diode:

We connect the legs of the diode to each other using a wire (bypass). During dismantling, static electricity may accumulate and the diode may fail.
Remove the aluminum radiator. It is quite fragile, has a mount that is structurally “tailored” for a specific DVD drive, and is not needed for further operation. Just cut the radiator with wire cutters (without damaging the diode)
We unsolder the diode and free the legs from the shunt.

The element looks like this:

Next important element– laser power supply circuit. You won't be able to use the power supply from the DVD drive. It is integrated into general scheme control, it is technically impossible to remove it from there. Therefore, we make the power supply circuit ourselves.

The output resistor R1 is selected in accordance with the supply current of the laser diode. In this circuit, the current should correspond to 200 mA.

The advantage of this solution is that you get a ready-made adjustable lens included. The power supply circuit (driver) easily fits into the module housing.

Important! Focusing the beam is necessary for any design. It can be parallel (if you need range) or cone-shaped (if you need to get a concentrated thermal spot).

The lens complete with a control device is called a collimator.

The negative contact has an electrical connection with the diode body. Finding it won't be difficult. Regarding the minus located at the bottom, the positive contact will be on the right.

With the help of such a tool you can do engraving, wood burning, and cutting fusible materials (fabric, cardboard, felt, polystyrene foam, etc.).

How to make an even more powerful laser?

The main thing is that such technologies are available for self-production.

Step-by-step video instructions on how to make a laser from a DVD drive with your own hands

Many of you have probably heard that you can make a laser pointer or even a cutting beam at home using simple improvised means, but few people know how to make a laser yourself. Before you start working on it, be sure to familiarize yourself with the safety precautions.

Safety rules when working with laser

Make sure there are no animals or children in the testing room.
Never point the beam at animals or people.
Wear safety glasses, such as welding glasses.
Remember that even a reflected beam can damage your vision. Never shine a laser into your eyes.
Do not use the laser to ignite objects while indoors.

The simplest laser from a computer mouse

Thus, the simplest laser is ready.

If a weak beam is not enough for you, and you are interested in how to make a laser at home from improvised means with sufficiently high power, then you should try a more complex method of making it, using a DVD-RW drive.

To work you will need:

DVD-RW drive (write speed must be at least 16x);
AAA battery, 3 pcs.;
resistor (from two to five ohms);
collimator (can be replaced with a part from a cheap Chinese laser pointer);
capacitors 100 pF and 100 mF;
LED lamp made of steel;
wires and soldering iron.

Work progress:

The first thing we need is a laser diode. It is located in the DVD-RW drive carriage. It has a larger heatsink than a regular infrared diode. But be careful, this part is very fragile. While the diode is not installed, it is best to wrap its lead with wire, since it is too sensitive to static voltage. Pay special attention to polarity. If the power supply is incorrect, the diode will immediately fail.

Watch the video: Laser from a DVD drive at home and with your own hands

Today we will talk about how to make a powerful green or blue laser yourself at home from scrap materials with your own hands. We will also consider drawings, diagrams and the design of homemade laser pointers with an igniting beam and a range of up to 20 km

The basis of the laser device is an optical quantum generator, which, using electrical, thermal, chemical or other energy, produces a laser beam.

Laser operation is based on the phenomenon of forced (induced) radiation. Laser radiation can be continuous, with constant power, or pulsed, reaching extremely high peak powers. The essence of the phenomenon is that an excited atom is capable of emitting a photon under the influence of another photon without its absorption, if the energy of the latter is equal to the difference in the energies of the levels of the atom before and after the radiation. In this case, the emitted photon is coherent with the photon that caused the radiation, that is, it is its an exact copy. This way the light is amplified. This phenomenon differs from spontaneous radiation, in which the emitted photons have random propagation directions, polarization and phase
The probability that a random photon will cause stimulated emission from an excited atom is exactly equal to the probability of absorption of this photon by an atom in an unexcited state. Therefore, to amplify light, it is necessary that there be more excited atoms in the medium than unexcited ones. In a state of equilibrium, this condition is not satisfied, so we use various systems pumping the laser active medium (optical, electrical, chemical, etc.). In some schemes, the laser working element is used as an optical amplifier for radiation from another source.

There is no external flow of photons in a quantum generator; an inverse population is created inside it using various pump sources. Depending on the sources there are various ways pumping:
optical - powerful flash lamp;
gas discharge in the working substance (active medium);
injection (transfer) of current carriers in a semiconductor in the zone
r-n transitions;
electronic excitation (irradiation of a pure semiconductor in a vacuum with a flow of electrons);
thermal (heating of gas followed by rapid cooling;
chemical (using the energy of chemical reactions) and some others.

The primary source of generation is the process of spontaneous emission, therefore, to ensure the continuity of generations of photons, the existence of a positive feedback is necessary, due to which the emitted photons cause subsequent acts of induced emission. To do this, the laser active medium is placed in an optical cavity. In the simplest case, it consists of two mirrors, one of which is translucent - through it the laser beam partially exits the resonator.

Reflecting from the mirrors, the radiation beam passes repeatedly through the resonator, causing induced transitions in it. The radiation can be either continuous or pulsed. At the same time, using various devices to quickly turn the feedback off and on and thereby reduce the period of the pulses, it is possible to create conditions for generating radiation of very high power - these are the so-called giant pulses. This mode of laser operation is called Q-switched mode.
The laser beam is a coherent, monochrome, polarized, narrowly directed light flux. In a word, this is a beam of light emitted not only by synchronous sources, but also in a very narrow range, and directionally. A sort of extremely concentrated light flux.

The radiation generated by a laser is monochromatic, the probability of emission of a photon of a certain wavelength is greater than that of a closely located one, associated with the broadening of the spectral line, and the probability of induced transitions at this frequency also has a maximum. Therefore, gradually during the generation process, photons of a given wavelength will dominate over all other photons. In addition, due to the special arrangement of the mirrors, only those photons that propagate in a direction parallel to the optical axis of the resonator at a short distance from it are retained in the laser beam; the remaining photons quickly leave the resonator volume. Thus, the laser beam has a very small divergence angle. Finally, the laser beam has a strictly defined polarization. To do this, various polarizers are introduced into the resonator; for example, they can be flat glass plates installed at a Brewster angle to the direction of propagation of the laser beam.

The working wavelength of the laser, as well as other properties, depend on what working fluid is used in the laser. The working fluid is “pumped” with energy to obtain the effect of electron population inversion, which causes stimulated emission of photons and an optical amplification effect. The simplest form optical resonator are two parallel mirrors a (there can also be four or more) located around the laser working fluid. The stimulated radiation of the working fluid is reflected back by the mirrors and is again amplified. Until the moment it comes out, the wave can be reflected many times.

So, let us briefly formulate the conditions necessary to create a source of coherent light:

you need a working substance with inverted population. Only then can light amplification be achieved through forced transitions;
the working substance should be placed between the mirrors that provide feedback;
the gain given by the working substance, which means the number of excited atoms or molecules in the working substance must be greater than a threshold value depending on the reflection coefficient of the output mirror.

The following types of working fluids can be used in the design of lasers:

Liquid. It is used as a working fluid, for example, in dye lasers. Includes: organic solvent(methanol, ethanol or ethylene glycol) in which chemical dyes (coumarin or rhodamine) are dissolved. The operating wavelength of liquid lasers is determined by the configuration of the dye molecules used.

Gases. In particular, carbon dioxide, argon, krypton or gas mixtures, as in helium-neon lasers. “Pumping” with the energy of these lasers is most often carried out using electrical discharges.
Solids (crystals and glasses). The solid material of such working fluids is activated (doped) by adding a small amount of chromium, neodymium, erbium or titanium ions. Commonly used crystals are: yttrium aluminum garnet, lithium yttrium fluoride, sapphire (aluminum oxide), and silicate glass. Solid-state lasers are usually "pumped" by a flash lamp or other laser.

Semiconductors. A material in which the transition of electrons between energy levels can be accompanied by radiation. Semiconductor lasers are very compact and "pumped" by electrical current, allowing them to be used in consumer devices such as CD players.

To turn an amplifier into an oscillator, it is necessary to organize feedback. In lasers, this is achieved by placing the active substance between reflecting surfaces (mirrors), forming a so-called “open resonator” due to the fact that part of the energy emitted by the active substance is reflected from the mirrors and again returns to the active substance

The Laser uses optical resonators of various types - with flat mirrors, spherical, combinations of flat and spherical, etc. In optical resonators that provide feedback in the Laser, only certain types of oscillations of the electromagnetic field can be excited, which are called natural oscillations or modes of the resonator.

Modes are characterized by frequency and shape, i.e., the spatial distribution of vibrations. In a resonator with flat mirrors, the types of oscillations corresponding to plane waves propagating along the axis of the resonator are predominantly excited. A system of two parallel mirrors resonates only at certain frequencies - and in the laser also plays the role that an oscillatory circuit plays in conventional low-frequency generators.

The use of an open resonator (and not a closed one - a closed metal cavity - characteristic of the microwave range) is fundamental, since in the optical range a resonator with dimensions L = ? (L is the characteristic size of the resonator, ? is the wavelength) simply cannot be manufactured, and at L >> ? a closed resonator loses its resonant properties because the number of possible types of oscillations becomes so large that they overlap.

The absence of side walls significantly reduces the number of possible types of oscillations (modes) due to the fact that waves propagating at an angle to the axis of the resonator quickly go beyond its limits, and allows maintaining the resonant properties of the resonator at L >> ?. However, the resonator in the laser not only provides feedback by returning radiation reflected from the mirrors to the active substance, but also determines the spectrum of the laser radiation, its energy characteristics, and the direction of the radiation.
In the simplest approximation of a plane wave, the condition for resonance in a resonator with flat mirrors is that an integer number of half-waves fits along the length of the resonator: L=q(?/2) (q is an integer), which leads to an expression for the frequency of the oscillation type with the index q: ?q=q(C/2L). As a result, the radiation spectrum of light, as a rule, is a set of narrow spectral lines, the intervals between which are identical and equal to c/2L. The number of lines (components) for a given length L depends on the properties of the active medium, i.e., on the spectrum of spontaneous emission at the quantum transition used and can reach several tens and hundreds. Under certain conditions, it turns out to be possible to isolate one spectral component, i.e., to implement a single-mode lasing mode. The spectral width of each component is determined by the energy losses in the resonator and, first of all, by the transmission and absorption of light by the mirrors.

The frequency profile of the gain in the working substance (it is determined by the width and shape of the line of the working substance) and the set of natural frequencies of the open resonator. For open resonators with a high quality factor used in lasers, the resonator passband ??p, which determines the width of the resonance curves of individual modes, and even the distance between neighboring modes ??h turn out to be less than the gain linewidth ??h, and even in gas lasers, where the line broadening is the smallest. Therefore, several types of resonator oscillations enter the amplification circuit.

Thus, the laser does not necessarily generate at one frequency; more often, on the contrary, generation occurs simultaneously at several types of oscillations, for which the amplification? more losses in the resonator. In order for the laser to operate at one frequency (in single-frequency mode), it is necessary, as a rule, to take special measures (for example, increase losses, as shown in Figure 3) or change the distance between the mirrors so that only one gets into the gain circuit. fashion. Since in optics, as noted above, ?h > ?p and the generation frequency in a laser is determined mainly by the resonator frequency, then in order to keep the generation frequency stable, it is necessary to stabilize the resonator. So, if the gain in the working substance covers the losses in the resonator for certain types of oscillations, generation occurs on them. The seed for its occurrence is, as in any generator, noise, which represents spontaneous emission in lasers.
In order for the active medium to emit coherent monochromatic light, it is necessary to introduce feedback, i.e., part of the light flux emitted by this medium is directed back into the medium to produce stimulated emission. Positive feedback is carried out using optical resonators, which in the elementary version are two coaxially (parallel and along the same axis) mirrors, one of which is translucent, and the other is “deaf,” i.e., it completely reflects the light flux. The working substance (active medium), in which an inverse population is created, is placed between the mirrors. Stimulated radiation passes through the active medium, is amplified, reflected from the mirror, passes through the medium again and is further amplified. Through a translucent mirror, part of the radiation is emitted into the external environment, and part is reflected back into the environment and amplified again. At certain conditions the flux of photons inside the working substance will begin to increase like an avalanche, and the generation of monochromatic coherent light will begin.

The principle of operation of an optical resonator, the predominant number of particles of the working substance, represented by open circles, are in the ground state, i.e., at the lower energy level. Only a small number of particles, represented by dark circles, are in an electronically excited state. When the working substance is exposed to a pumping source, the majority of particles go into an excited state (the number of dark circles has increased), and an inverse population is created. Next (Fig. 2c), spontaneous emission occurs from some particles in an electronically excited state. Radiation directed at an angle to the axis of the resonator will leave the working substance and the resonator. Radiation, which is directed along the axis of the resonator, will approach the mirror surface.

For a translucent mirror, part of the radiation will pass through it into environment, and part of it will be reflected and again directed into the working substance, involving particles in an excited state in the process of stimulated emission.

At the “deaf” mirror, the entire radiation flux will be reflected and again pass through the working substance, inducing radiation from all remaining excited particles, which reflects the situation when all the excited particles gave up their stored energy, and at the output of the resonator, on the side of the translucent mirror, a powerful flux of induced radiation was formed.

The main structural elements of lasers include a working substance with certain energy levels of their constituent atoms and molecules, a pump source that creates population inversion in the working substance, and an optical cavity. There are a large number of different lasers, but they all have the same and, moreover, simple circuit diagram of the device, which is presented in Fig. 3.

The exception is semiconductor lasers due to their specificity, since everything about them is special: the physics of the processes, pumping methods, and design. Semiconductors are crystalline formations. In an individual atom, the electron energy takes on strictly defined discrete values, and therefore the energy states of an electron in an atom are described in the language of levels. In a semiconductor crystal, energy levels form energy bands. In a pure semiconductor that does not contain any impurities, there are two bands: the so-called valence band and the conduction band located above it (on the energy scale).

Between them there is a gap of forbidden energy values, which is called the bandgap. At a semiconductor temperature equal to absolute zero, the valence band should be completely filled with electrons, and the conduction band should be empty. In real conditions, the temperature is always above absolute zero. But an increase in temperature leads to thermal excitation of electrons, some of them jump from the valence band to the conduction band.

As a result of this process, a certain (relatively small) number of electrons appears in the conduction band, and a corresponding number of electrons will be missing in the valence band until it is completely filled. An electron vacancy in the valence band is represented by a positively charged particle, which is called a hole. The quantum transition of an electron through the band gap from bottom to top is considered as a process of generating an electron-hole pair, with electrons concentrated at the lower edge of the conduction band, and holes at the upper edge of the valence band. Transitions through the forbidden zone are possible not only from bottom to top, but also from top to bottom. This process is called electron-hole recombination.

When a pure semiconductor is irradiated with light whose photon energy slightly exceeds the band gap, three types of interaction of light with matter can occur in the semiconductor crystal: absorption, spontaneous emission and stimulated emission of light. The first type of interaction is possible when a photon is absorbed by an electron located near the upper edge of the valence band. In this case, the energy power of the electron will become sufficient to overcome the band gap, and it will make a quantum transition to the conduction band. Spontaneous emission of light is possible when an electron spontaneously returns from the conduction band to the valence band with the emission of an energy quantum - a photon. External radiation can initiate the transition to the valence band of an electron located near the lower edge of the conduction band. The result of this third type of interaction of light with the semiconductor substance will be the birth of a secondary photon, identical in its parameters and direction of movement to the photon that initiated the transition.

To generate laser radiation, it is necessary to create an inverse population of “working levels” in the semiconductor - to create a sufficiently high concentration of electrons at the lower edge of the conduction band and a correspondingly high concentration of holes at the edge of the valence band. For these purposes, pure semiconductor lasers are usually pumped by an electron flow.

The resonator mirrors are polished edges of the semiconductor crystal. The disadvantage of such lasers is that many semiconductor materials generate laser radiation only at very high low temperatures, and the bombardment of semiconductor crystals by a stream of electrons causes it to heat up greatly. This requires additional cooling devices, which complicates the design of the device and increases its dimensions.

The properties of semiconductors with impurities differ significantly from the properties of unimpurity, pure semiconductors. This is due to the fact that atoms of some impurities easily donate one of their electrons to the conduction band. These impurities are called donor impurities, and a semiconductor with such impurities is called an n-semiconductor. Atoms of other impurities, on the contrary, capture one electron from the valence band, and such impurities are acceptor, and a semiconductor with such impurities is a p-semiconductor. Energy level impurity atoms is located inside the band gap: for n-semiconductors - near the lower edge of the conduction band, for /-semiconductors - near the upper edge of the valence band.

If an electric voltage is created in this area so that there is a positive pole on the side of the p-semiconductor, and a negative pole on the side of the p-semiconductor, then under the influence electric field electrons from the n-semiconductor and holes from the n-semiconductor will move (inject) into the region of the p-n junction.

When electrons and holes recombine, photons will be emitted, and in the presence of an optical resonator, laser radiation can be generated.

The mirrors of the optical resonator are polished edges of the semiconductor crystal, oriented perpendicularly p-n plane- transition. Such lasers are miniature, since the size of the semiconductor active element can be about 1 mm.

Depending on the characteristic under consideration, all lasers are divided as follows).

First sign. It is customary to distinguish between laser amplifiers and generators. In amplifiers, weak laser radiation is supplied at the input, and it is correspondingly amplified at the output. There is no external radiation in the generators; it arises in the working substance due to its excitation using various pump sources. All medical laser devices are generators.

The second sign is the physical state of the working substance. In accordance with this, lasers are divided into solid-state (ruby, sapphire, etc.), gas (helium-neon, helium-cadmium, argon, carbon dioxide, etc.), liquid (liquid dielectric with impurity working atoms of rare earth metals) and semiconductor (arsenide -gallium, gallium arsenide phosphide, lead selenide, etc.).

The method of exciting the working substance is the third hallmark lasers. Depending on the excitation source, lasers are distinguished: optically pumped, pumped by a gas discharge, electronic excitation, injection of charge carriers, thermally pumped, chemically pumped, and some others.

The laser emission spectrum is the next classification feature. If the radiation is concentrated in a narrow range of wavelengths, then the laser is considered monochromatic and its technical data indicates a specific wavelength; if in a wide range, then the laser should be considered broadband and the wavelength range is indicated.

Based on the nature of the emitted energy, pulsed lasers and lasers with continuous radiation are distinguished. The concepts of a pulsed laser and a laser with frequency modulation of continuous radiation should not be confused, since in the second case we essentially receive intermittent radiation of various frequencies. Pulsed lasers have high power in a single pulse, reaching 10 W, while their average pulse power, determined by the corresponding formulas, is relatively small. For continuous frequency modulated lasers, the power in the so-called pulse is lower than the power of continuous radiation.

Based on the average radiation output power (the next classification feature), lasers are divided into:

· high-energy (generated flux density, radiation power on the surface of an object or biological object - over 10 W/cm2);

· medium-energy (generated radiation power flux density - from 0.4 to 10 W/cm2);

· low-energy (the generated radiation power flux density is less than 0.4 W/cm2).

· soft (generated energy irradiation - E or power flux density on the irradiated surface - up to 4 mW/cm2);

· average (E - from 4 to 30 mW/cm2);

· hard (E - more than 30 mW/cm2).

In accordance with the “Sanitary norms and rules for the design and operation of lasers No. 5804-91,” lasers are divided into four classes according to the degree of danger of the generated radiation for operating personnel.

First class lasers include such technical devices whose output collimated (confined in a limited solid angle) radiation does not pose a danger when irradiating human eyes and skin.

Second class lasers are devices whose output radiation poses a danger when irradiating the eyes with direct and specularly reflected radiation.

Lasers of the third class are devices whose output radiation poses a danger when irradiating the eyes with direct and specularly reflected, as well as diffusely reflected radiation at a distance of 10 cm from a diffusely reflective surface, and (or) when irradiating the skin with direct and specularly reflected radiation.

Fourth class lasers are devices whose output radiation poses a hazard when the skin is irradiated with diffusely reflected radiation at a distance of 10 cm from a diffusely reflective surface.

From an old or broken DVD drive
From a computer mouse and flashlight
From a kit of parts purchased at an electronics store

How to make a laser at home from an old oneDVDdrive

Find a non-working or unwanted DVD drive that has a recording speed greater than 16x and outputs more than 160mW of power. Why can't you take a recordable CD, you ask? The fact is that its diode emits infrared light, invisible to the human eye.
Remove the laser head from the drive. To access the “internals”, unscrew the screws located on the bottom of the drive and remove the laser head, which is also held in place by screws. It may be in a shell or under a transparent window, or maybe even outside. The most difficult thing is to remove the diode itself from it. Caution: The diode is very sensitive to static electricity.
Get a lens, without which it will be impossible to use the diode. You can use a regular magnifying glass, but then you will have to twist and adjust it every time. Or you can purchase another diode included with the lens, and then replace it with the diode removed from the drive.
Next you will have to buy or assemble a circuit to power the diode and assemble the structure together. In a DVD drive diode, the center pin acts as the negative terminal.
Connect a suitable power source and focus the lens. All that remains is to find a suitable container for the laser. You can use a metal flashlight of suitable size for these purposes.
We recommend watching this video, where everything is shown in great detail:

How to make a laser from a computer mouse

The power of a laser made from a computer mouse will be much less than the power of a laser made using the previous method. The manufacturing procedure is not very different.

First, find an old or unwanted mouse with a visible laser of any color. Mice with an invisible glow are not suitable for obvious reasons.
Next, carefully disassemble it. Inside you will notice a laser that will have to be soldered using a soldering iron.
Now repeat steps 3-5 from the instructions above. The difference between such lasers, we repeat, is only in power.

The basis of the laser device is an optical quantum generator, which, using electrical, thermal, chemical or other energy, produces a laser beam.

Laser operation is based on the phenomenon of forced (induced) radiation. Laser radiation can be continuous, with constant power, or pulsed, reaching extremely high peak powers. The essence of the phenomenon is that an excited atom is capable of emitting a photon under the influence of another photon without its absorption, if the energy of the latter is equal to the difference in the energies of the levels of the atom before and after the radiation. In this case, the emitted photon is coherent with the photon that caused the radiation, that is, it is its exact copy. This way the light is amplified. This phenomenon differs from spontaneous radiation, in which the emitted photons have random propagation directions, polarization and phase
The probability that a random photon will cause stimulated emission from an excited atom is exactly equal to the probability of absorption of this photon by an atom in an unexcited state. Therefore, to amplify light, it is necessary that there be more excited atoms in the medium than unexcited ones. In a state of equilibrium, this condition is not satisfied, so various systems for pumping the laser active medium are used (optical, electrical, chemical, etc.). In some schemes, the laser working element is used as an optical amplifier for radiation from another source.

There is no external flow of photons in a quantum generator; an inverse population is created inside it using various pump sources. Depending on the sources, there are different pumping methods:
optical - powerful flash lamp;
gas discharge in the working substance (active medium);
injection (transfer) of current carriers in a semiconductor in the zone
p-n transitions;
electronic excitation (irradiation of a pure semiconductor in a vacuum with a flow of electrons);
thermal (heating of gas followed by rapid cooling;
chemical (using the energy of chemical reactions) and some others.

The working wavelength of the laser, as well as other properties, depend on what working fluid is used in the laser. The working fluid is “pumped” with energy to obtain the effect of electron population inversion, which causes stimulated emission of photons and an optical amplification effect. The simplest form of an optical resonator is two parallel mirrors (there can also be four or more) located around the laser working fluid. The stimulated radiation of the working fluid is reflected back by the mirrors and is again amplified. Until the moment it comes out, the wave can be reflected many times.

So, let us briefly formulate the conditions necessary to create a source of coherent light:

The following types of working fluids can be used in the design of lasers:

Liquid. It is used as a working fluid, for example, in dye lasers. The composition includes an organic solvent (methanol, ethanol or ethylene glycol) in which chemical dyes (coumarin or rhodamine) are dissolved. The operating wavelength of liquid lasers is determined by the configuration of the dye molecules used.

Semiconductors. A material in which the transition of electrons between energy levels can be accompanied by radiation. Semiconductor lasers are very compact and “pumpable” electric shock, allowing them to be used in consumer devices such as CD players.

The laser uses optical resonators various types- with flat mirrors, spherical, combinations of flat and spherical, etc. In optical resonators that provide feedback in the Laser, only certain specific types of oscillations of the electromagnetic field can be excited, which are called natural oscillations or modes of the resonator.

Thus, the laser does not necessarily generate at one frequency; more often, on the contrary, generation occurs simultaneously at several types of oscillations, for which the amplification? more losses in the resonator. In order for the laser to operate at one frequency (in single-frequency mode), it is necessary, as a rule, to take special measures (for example, increase losses, as shown in Figure 3) or change the distance between the mirrors so that only one gets into the gain circuit. fashion. Since in optics, as noted above, ?h > ?p and the generation frequency in a laser is determined mainly by the resonator frequency, then in order to keep the generation frequency stable, it is necessary to stabilize the resonator. So, if the gain in the working substance covers the losses in the resonator for certain types of oscillations, generation occurs on them. The seed for its occurrence is, as in any generator, noise, which represents spontaneous emission in lasers.
In order for the active medium to emit coherent monochromatic light, it is necessary to introduce feedback, i.e., part of what is emitted by this medium luminous flux send back into the medium to produce stimulated emission. Positive feedback is carried out using optical resonators, which in the elementary version are two coaxially (parallel and along the same axis) mirrors, one of which is translucent, and the other is “deaf,” i.e., completely reflects the light flux. The working substance (active medium), in which an inverse population is created, is placed between the mirrors. Stimulated radiation passes through the active medium, is amplified, reflected from the mirror, passes through the medium again and is further amplified. Through a translucent mirror, part of the radiation is emitted into the external environment, and part is reflected back into the environment and amplified again. Under certain conditions, the flux of photons inside the working substance will begin to increase like an avalanche, and the generation of monochromatic coherent light will begin.

In a translucent mirror, part of the radiation will pass through it into the environment, and part will be reflected and again directed into the working substance, involving particles in an excited state in the process of stimulated emission.

The main structural elements of lasers include a working substance with certain energy levels of their constituent atoms and molecules, a pump source that creates population inversion in the working substance, and an optical cavity. There are a large number of different lasers, but they all have the same and simple schematic diagram device, which is shown in Fig. 3.

The exception is semiconductor lasers due to their specificity, since everything about them is special: the physics of the processes, pumping methods, and design. Semiconductors are crystalline formations. In an individual atom, the electron energy takes on strictly defined discrete values, and therefore the energy states of the electron in the atom are described in the language of levels. In a semiconductor crystal, energy levels form energy bands. In a pure semiconductor that does not contain any impurities, there are two bands: the so-called valence band and the conduction band located above it (on the energy scale).

To generate laser radiation, it is necessary to create an inverse population of “working levels” in the semiconductor—to create a sufficiently high concentration of electrons at the lower edge of the conduction band and a correspondingly high concentration of holes at the edge of the valence band. For these purposes, pure semiconductor lasers are usually pumped by an electron flow.

The resonator mirrors are polished edges of the semiconductor crystal. The disadvantage of such lasers is that many semiconductor materials generate laser radiation only at very low temperatures, and the bombardment of semiconductor crystals by a stream of electrons causes it to become very hot. This requires additional cooling devices, which complicates the design of the device and increases its dimensions.

The properties of semiconductors with impurities differ significantly from the properties of unimpurity, pure semiconductors. This is due to the fact that atoms of some impurities easily donate one of their electrons to the conduction band. These impurities are called donor impurities, and a semiconductor with such impurities is called an n-semiconductor. Atoms of other impurities, on the contrary, capture one electron from the valence band, and such impurities are acceptor, and a semiconductor with such impurities is a p-semiconductor. The energy level of impurity atoms is located inside the band gap: for n-semiconductors - near the lower edge of the conduction band, for /-semiconductors - near the upper edge of the valence band.

If an electric voltage is created in this region so that there is a positive pole on the side of the p-semiconductor and a negative pole on the side of the n-semiconductor, then under the influence of the electric field electrons from the n-semiconductor and holes from the /^-semiconductor will move (injected) into region of p-n transition.

When electrons and holes recombine, photons will be emitted, and in the presence of an optical resonator, laser radiation can be generated.

The mirrors of the optical resonator are polished edges of the semiconductor crystal, oriented perpendicular to the plane of the pn junction. Such lasers are miniature, since the size of the semiconductor active element can be about 1 mm.

Depending on the characteristic under consideration, all lasers are divided as follows).

The method of exciting the working substance is the third distinctive feature of lasers. Depending on the excitation source, lasers are distinguished: optically pumped, pumped by a gas discharge, electronic excitation, injection of charge carriers, thermally pumped, chemically pumped, and some others.

Based on the average radiation output power (the next classification feature), lasers are divided into:

· high-energy (the generated radiation power flux density on the surface of an object or biological object is over 10 W/cm2);

· medium-energy (generated radiation power flux density - from 0.4 to 10 W/cm2);

· low-energy (the generated radiation power flux density is less than 0.4 W/cm2).

· soft (generated energy irradiation - E or power flux density on the irradiated surface - up to 4 mW/cm2);

· average (E - from 4 to 30 mW/cm2);

· hard (E - more than 30 mW/cm2).

In accordance with " Sanitary standards and rules for the design and operation of lasers No. 5804-91”, according to the degree of danger of the generated radiation for operating personnel, lasers are divided into four classes.

First class lasers include: technical devices, the output collimated (enclosed in a limited solid angle) radiation of which does not pose a danger when irradiating human eyes and skin.

Second class lasers are devices whose output radiation poses a danger when irradiating the eyes with direct and specularly reflected radiation.

Class 4 lasers are devices whose output radiation poses a hazard when the skin is irradiated with diffusely reflected radiation at a distance of 10 cm from a diffusely reflective surface.

Warning!

Let's find out.

Let's cook.

This minimum required to make a simple driver model. The driver is, in fact, a board that will output our laser diode to the required power. You should not connect the power source directly to the laser diode - it will break down. The laser diode must be powered with current, not voltage.

A collimator is, in fact, a module with a lens that reduces all radiation into a narrow beam. Ready-made collimators can be purchased at radio stores. These immediately have a convenient place to install a laser diode, and the cost is 200-500 rubles.

Let's do it.

According to this scheme, you need to solder the driver.

Don't mix up the polarity! The laser diode will also fail instantly if the polarity of the supplied power is incorrect.

The diagram shows a 200 mF capacitor, however, for portability, 50-100 mF is quite enough.

Let's try.

Looks terrible, but it works!

Aesthetics.

This is an option with minimal costs - a collimator from a Chinese pointer is used:

Using a factory-made module will allow you to get the following results:

The laser beam is visible in the evening:

And, of course, in the dark:

Maybe.

We need to remember.

Don't forget about safety precautions! Lasers are not a toy! Take care of your eyes!

When mentioning a laser, most people immediately recall episodes from science fiction films. However, such an invention has long been firmly established in our lives and is not something fantastic. The laser has found its application in many areas, from medicine and manufacturing to entertainment. Therefore, many people are wondering whether and how to make a laser themselves.

Making a laser at home

Depending on the specifics and requirements put forward, lasers can be completely different, both in size (from pocket pointers to the size of a football field), and in power, the working media used and other parameters. Of course, it is impossible to make a powerful production beam yourself at home, since these are not only technically complex devices, but also very difficult to maintain things. But you can make a simple, but reliable and powerful laser with your own hands from a regular DVD-RW drive.

Principle of operation

The word "laser" came to us from in English“laser”, which is an abbreviation of the first letters of a much more complex name: light amplification by stimulated emission of radiation and literally translates as “light amplification through stimulated emission”. It can also be called an optical quantum generator. There are many types of lasers, and their scope of application is extremely wide.

The principle of its operation is to convert one energy (light, chemical, electrical) into the energy of various radiation fluxes, that is, it is based on the phenomenon of forced or induced radiation.

Conventionally, the operating principle is shown in the following drawing:

Materials required for work

When describing the basics of laser operation, everything looks complicated and unclear. In fact, making a laser with your own hands at home is extremely simple. You will need some components and tools:

The most basic thing you need to create a laser is a DVD-RW drive, that is, a burner drive from a computer or player. The higher the recording speed, the more powerful the product itself will be. It is preferable to take drives with a speed of 22X, since its power is the highest, about 300 mW. At the same time, they differ in color: red, green, purple. As for non-writing ROMs, they are too weak. It is also worth paying attention to the fact that after manipulating the drive, it will no longer work, so you should take either one that is already out of order, but with a working laser, or one that you won’t be sorry to say goodbye to.
You will also need a current stabilizer, although there is a desire to do without it. But it is worth knowing that all diodes (and laser diodes are no exception) “prefer” not voltage, but current. The cheapest and most preferred options are pulse converter NCP1529 or LM317 chip (analogous to KR142EN12).
The output resistor is selected depending on the supply current of the laser diode. It is calculated using the formula: R=I/1.25, where I is the rated current of the laser.
Two capacitors: 0.1 µF and 100 µF.
Collimator or laser pointer.
AAA standard batteries.
Wires.
Tools: soldering iron, screwdrivers, pliers, etc.

Removing the laser diode from the DVD drive

The main part that needs to be removed is the laser from the DVD drive. This is not difficult to do, but it is worth knowing some nuances that will help avoid possible misunderstandings during work.

First of all, the DVD drive needs to be disassembled to get to the carriage on which the laser diodes are located. One of them is a reader - it is too low-power. The second writer is exactly what you need to make a laser from a DVD drive.

On the carriage, the diode is installed on the radiator and securely fastened. If you don’t plan to use another radiator, then the existing one is quite suitable. Therefore, you need to remove them together. Otherwise, carefully cut off the legs at the entrance to the radiator.

Since diodes are extremely sensitive to static, it is a good idea to protect them. To do this, you need to wind the legs of the laser diode together with a thin wire.

All that remains is to put all the details together, and the ROM itself is no longer needed.

Assembling the laser device

It is necessary to connect the diode removed from the LED to the converter, observing the polarity, since otherwise the laser diode will immediately fail and become unsuitable for further use.

A collimator is installed on the back side of the diode so that the light can be concentrated into one beam. Although, instead, you can use the lens included in the rum, or the lens that the laser pointer already contains. But in this case, you will have to make adjustments to get the required focus.

On the other side of the converter, wires are soldered, connecting to the contacts of the case where the batteries will be installed.

This diagram will help you complete a laser from a DVD drive with your own hands:

When all components are connected, you can check the functionality of the resulting device. If everything works, then all that remains is to place the entire structure in the housing and securely fasten it there.

Homemade body design

You can approach the manufacture of the case in different ways. For example, a case from Chinese lantern. You can also use a ready-made laser pointer body. But optimal solution It may turn out to be homemade, made from an aluminum profile.

Aluminum itself is lightweight and, at the same time, very easy to process. The entire structure will be conveniently located in it. It will also be convenient to secure it. If necessary, you can always easily cut out the required piece or bend it in accordance with the required parameters.

Safety and Testing

When all the work is completed, it is time to test the resulting powerful laser. It is not recommended to do this indoors. Therefore, it is better to go outside to a deserted place. At the same time, it is worth remembering that the device made is several hundred times more powerful than a conventional laser pointer, and this requires using it with extreme caution. Do not direct the beam at people or animals; be careful that the beam does not reflect or get into your eyes. When using a red laser beam, it is recommended to wear green glasses; this will significantly reduce the risk of vision damage in unexpected cases. After all, it is not recommended to look at laser beams even from the outside.

Do not direct the laser beam at flammable or explosive objects and substances.

The created device, with a correctly configured lens, can quite cut plastic bags, burning on wood, popping balloons and even burning - a kind of combat laser. It's incredible what you can do with a DVD drive. Therefore, when testing a manufactured device, you should always remember safety precautions.