DIY lasers. How to make a powerful laser with your own hands

The word “laser” or “laser” is an abbreviation for “light amplification by stimulated emission of radiation.” In Russian: - “amplification of light by stimulated emission”, or an optical quantum generator. The first laser, which used a silver-coated ruby ​​cylinder as a resonator, was developed in 1960 by Hughes Research Laboratories, California. .Today, lasers are used for a variety of purposes ranging from measuring various sizes before reading the encoded data. There are several ways to make a laser, depending on your budget and skills.

Steps

Part 1

The laser needs a power source to operate. Lasers work by excitation of electrons in the active medium of the laser external source energy and stimulate them to emit light of a certain wavelength. This process was first proposed in 1917 by Albert Einstein. In order for the electrons (in the atoms of the active medium of the laser) to emit light, they must first absorb energy by moving to a higher orbit, and then give this energy in the form of a particle of light when returning to the original orbit. This way of introducing energy into the laser active medium is called “pumping.”

Channel passage of energy through an active (amplifying) medium. The amplifying medium or active laser medium increases the intensity of light due to induced (forced) emission emitted by electrons. The amplifying medium can be any structure or substance listed below:

Installing mirrors to hold the light inside the laser. Mirrors, or resonators, hold light within working chamber laser until the desired level of energy is accumulated for radiation through a small hole in one of the mirrors or through a lens.

• The simplest resonator or "linear resonator" uses two mirrors placed on opposite sides of the laser's working chamber to generate one output beam.
• A more complex "ring resonator" uses three or more mirrors. It can generate multiple beams or a single beam with an optical isolator.

1. The use of a focusing lens to direct light through an amplifying medium. Along with mirrors, the lens helps to concentrate and direct the light so that the amplifying medium receives as much light as possible.

   Part 2

   Construction of the Laser

   Method One: Building a Laser from a Kit

   1. Purchase. You can buy at an electronics store or buy online "laser kit", "laser kit", "laser module" or "laser diode". The laser kit should include the following:

      • Driver schema. Sometimes sold separately from other components. Choose a driver circuit that will allow you to regulate the current.
      • laser diode.
      • The adjusting lens can be glass or plastic. Typically, the diode and lens are bundled together in a small tube. These components are sometimes sold separately without a driver.

   2. Assembling the driver circuit. Many laser kits are sold with an unassembled driver. These sets include printed circuit board and the corresponding parts, and you have to solder them, following the attached diagram. Some kits may have the driver assembled.

      Connect the control unit to the laser diode. If you have a digital multimeter, you can include it in a diode circuit to monitor the current. Most laser diodes have a current in the range of 30 to 250 milliamps (mA). The current range from 100 to 150 mA will give a fairly powerful beam.

      • You can give more current to the laser diode to get a more powerful beam, but the extra current will shorten the life or even burn out the diode.

   3. Connect the power supply or battery to the driver circuit. The laser diode should glow brightly.

   4. Rotate the lens to focus the laser beam. Point it at the wall and focus until a nice, bright point appears.

      • Once you have adjusted the lens in this way, place the match in line with the beam and rotate the lens until you see the match head begin to smoke. You can also try to pop Balloons or burn holes in paper.

   Method Two: Building a Diode Laser from an Old DVD or Blu-Ray Drive

   1. Get an old DVD or Blu-ray burner or drive. Choose devices with 16x write speed or faster. These devices have laser diodes with an output power of 150mW or more.

      • DVD drive has a red laser diode with a wavelength of 650nm.
      • The Blu-ray drive has a blue laser diode with a wavelength of 405nm.
      • The DVD drive must be in good enough condition to burn discs, although not necessarily successfully. In other words, its diode must be good.
      • Do not try to use a DVD reader, CD reader and writer instead of a DVD writer. The DVD reader has a red diode, but not as powerful as the DVD burner. The laser diode in the CD burner is quite powerful, but emits light in the infrared range, and you will get a beam that is not visible to the eye.

   2. Removing the laser diode from the drive. Flip the drive bottom up. You will see screws that will need to be removed before you can separate the drive mechanism and pull out the diode.

      • Once you take the drive apart, you will see a pair of metal rails held in place with screws. They support the laser kit. Unscrew the guides to remove them. Remove the laser kit.
      • The laser diode is smaller than a penny. It has three metal contacts in the form of legs. It can be placed in a metal shell with a protective transparent window or without a window, or it can be not closed by anything.
      • You have to pull the diode out of the laser head. It may be easier to remove the heatsink from the assembly first before attempting to remove the diode. If you have an anti-static wrist strap, use it while removing the diode.
      • Handle the laser diode with care, especially if it is an unprotected diode. If you have an anti-static container, place the diode in it until you begin to assemble the laser.

   3. Prepare the focusing lens. You will have to pass the beam from the diode through a focusing lens to use it as a laser. You can do this in one of two ways:

      • Using a magnifying glass as a focusing lens. Rotate the lens to find the right place to receive the focused laser beam. If necessary, this will have to be done each time before using the laser.
      • Buy a little powerful laser ny diode, for example 5mW assembled with a lens and a tube. Then replace it with a laser diode from a DVD burner.

A laser pointer is a useful item, the purpose of which depends on the power. If it is not very large, then the beam can be aimed at distant objects. In this case, the pointer can play the role of a toy and be used for entertainment. It can also be of practical use, helping a person to point to the object he is talking about. Using improvised items, you can make a laser with your own hands.

Briefly about the device

The laser was invented as a result of testing the theoretical assumptions of scientists involved in the then just beginning to emerge quantum physics. The principle underlying the laser pointer was predicted by Einstein at the beginning of the 20th century. No wonder this device is so called - "pointer".

More powerful lasers are used for burning. The pointer provides an opportunity to realize creative potential, for example, they can be used to engrave a beautiful high-quality pattern on wood or plexiglass. The most powerful lasers can cut metal, which is why they are used in construction and repair work.

The principle of operation of a laser pointer

According to the principle of operation, the laser is a photon generator. The essence of the phenomenon that underlies it is that an atom is affected by energy in the form of a photon. As a result, this atom emits the next photon, which moves in the same direction as the previous one. These photons have the same phase and polarization. Of course, the emitted light is amplified in this case. Such a phenomenon can only occur in the absence of thermodynamic equilibrium. To create stimulated emission, apply different ways: chemical, electrical, gas and others.

The very word "laser" did not arise from scratch. It was formed as a result of the reduction of words describing the essence of the process. In English, the full name of this process sounds like this: “light amplification by stimulated emission of radiation”, which translates into Russian as “light amplification by stimulated emission”. Scientifically speaking, laser pointer is an optical quantum generator.

Preparing for production

As mentioned above, you can make a laser with your own hands at home. To do this, prepare the following tools, as well as simple items, which are almost always available at home:

These materials are enough to do all the work on the manufacture of both a simple and a powerful laser with your own hands.

Self-assembly of the laser

You will need to find a drive. The main thing is that its laser diode is in good working order. Of course, there may not be such an object at home. In this case, it can be purchased from those who have it. Often people throw away optical drives even if their laser diode is still working or selling them.

Choosing a drive for the manufacture of a laser device, you need to pay attention to the company in which it was issued. The main thing is that Samsung should not be this company: drives from this manufacturer are equipped with diodes that are not protected from external influences. Consequently, such diodes are quickly contaminated and subjected to thermal stress. They can be damaged even by a light touch.

The drives from LG are best suited for making a laser: each of their models is equipped with a powerful crystal.

It is important that the drive, when used for its intended purpose, can not only read, but also write information to the disk. Recording printers have an infrared emitter needed to assemble a laser device.

The work is in the following steps:

A ready-made DIY laser pointer can easily cut through plastic bags and instantly explode balloons. If you point this homemade device at wooden surface, then the beam will immediately burn it. When using, care must be taken.

Today we will talk about how to make a powerful green or blue laser yourself at home from improvised materials with your own hands. We will also consider drawings, diagrams and the device of self-made laser pointers with an incendiary 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.

The operation of a laser is based on the phenomenon of stimulated (induced) radiation. Laser radiation can be continuous, with a constant power, or pulsed, reaching extremely high peak power. The essence of the phenomenon is that an excited atom is able to emit 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 to the photon that caused the radiation, that is, it is its exact copy. This is how the light is amplified. This phenomenon differs from spontaneous emission, in which the emitted photons have random directions of propagation, polarization and phase.
The probability that a random photon will cause stimulated emission of 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 the state of equilibrium, this condition is not met, so we use various systems pumping the laser active medium (optical, electrical, chemical, etc.). In some schemes, the working element of the laser is used as an optical amplifier for radiation from another source.

There is no external photon flux in a quantum generator, the inverse population is created inside it with the help of various sources pumping. 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
p-n transitions;
electronic excitation (vacuum irradiation of a pure semiconductor by a stream of electrons);
thermal (heating the gas with its subsequent rapid cooling;
chemical (energy use chemical reactions) and some others.

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

Reflecting from the mirrors, the radiation beam repeatedly passes through the resonator, causing induced transitions in it. The radiation can be either continuous or pulsed. At the same time, using various devices for quickly turning off and on feedback and thereby reducing the pulse period, 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 narrow beam of light. In a word, this is a beam of light emitted not only by synchronous sources, but also in a very narrow range, and directed. A sort of extremely concentrated luminous flux.

The radiation generated by the laser is monochromatic, the probability of emitting a photon of a certain wavelength is greater than that of a closely spaced one associated with the broadening of the spectral line, and the probability of induced transitions at this frequency also has a maximum. Therefore, gradually in the process of generation, photons of a given wavelength will dominate over all other photons. In addition, due to the special arrangement of mirrors in laser beam only those photons are preserved that propagate in a direction parallel to the optical axis of the resonator at a small distance from it, the rest of the photons quickly leave the volume of the resonator. Thus, the laser beam has a very small angle of divergence. 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 the Brewster angle to the direction of propagation of the laser beam.

What working fluid is used in the laser depends on its working wavelength, as well as other properties. The working body is "pumped" with energy to obtain the effect of electron population inversion, which causes stimulated emission of photons and the effect of optical amplification. The simplest form The optical resonator consists of two parallel mirrors (there may also be four or more) located around the working body of the laser. The stimulated radiation of the working body is reflected back by the mirrors and again amplified. Until the moment of exit to the outside, 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 an inverse population. Only then it is possible to obtain amplification of light due to forced transitions;
the working substance should be placed between the mirrors that provide feedback;
the gain given by the working substance, which means that the number of excited atoms or molecules in the working substance must be greater than the threshold value, which depends on the reflection coefficient of the output mirror.

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

Liquid. It is used as a working fluid, for example, in dye lasers. The composition 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" the energy of these lasers is most often carried out with the help of electrical discharges.
Solids (crystals and glasses). The solid material of such working bodies is activated (alloyed) by adding a small amount of chromium, neodymium, erbium or titanium ions. Crystals commonly used are yttrium aluminum garnet, yttrium lithium fluoride, sapphire (aluminum oxide), and silicate glass. Solid state lasers are usually "pumped" with 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, "pumped up" electric shock, which allows them to be used in home appliances such as CD players.

To turn the amplifier into a generator, you need to organize feedback. In lasers, it is achieved by placing the active substance between reflecting surfaces (mirrors), which form the 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 various types- with flat mirrors, spherical, combinations of flat and spherical, etc. In optical cavities providing feedback in the Laser, only certain certain types of electromagnetic field oscillations, which are called natural oscillations or resonator modes, can be excited.

Modes are characterized by frequency and shape, i.e., by the spatial distribution of oscillations. 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 also performs in the laser the role that an oscillatory circuit plays in conventional low-frequency generators.

The use of an open resonator (rather than 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 made, and for L >> ? a closed resonator loses resonant properties as the number of possible modes of oscillation 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 resonator axis quickly go beyond its limits, and makes it possible to preserve the resonant properties of the resonator at L >> ?. However, the resonator in the laser not only provides feedback by returning the radiation reflected from the mirrors to the active substance, but also determines the laser radiation spectrum, its energy characteristics, and the radiation directivity.
In the simplest approximation of a plane wave, the resonance condition in a resonator with flat mirrors is that an integer number of half-waves fit along the length of the resonator: L=q(?/2) (q is an integer), which leads to an expression for the oscillation type frequency with the index q: ?q=q(C/2L). As a result, the emission spectrum of L., as a rule, is a set of narrow spectral lines, the intervals between which are the same 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 generation regime. The spectral width of each of the components 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 medium (it is determined by the width and shape of the line of the working medium) and the set of natural frequencies of the open resonator. For open resonators with a high quality factor used in lasers, the cavity bandwidth ??p, which determines the width of the resonance curves of individual modes, and even the distance between adjacent modes ??h, turn out to be smaller than the gain linewidth ??h, and even in gas lasers, where line broadening is minimal. Therefore, several types of resonator oscillations fall into 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 gain? more losses in the resonator. In order for the laser to operate at one frequency (in the single-frequency mode), it is usually necessary to take special measures (for example, increase the losses, as shown in Figure 3) or change the distance between the mirrors so that only one fashion. Since in optics, as noted above, ?h > ?p and the generation frequency in a laser is determined mainly by the resonator frequency, it is necessary to stabilize the resonator in order to keep the generation frequency stable. 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 is spontaneous emission in lasers.
In order for the active medium to emit coherent monochromatic light, it is necessary to introduce feedback, i.e., send part of the light flux emitted by this medium back into the medium for stimulated emission. Positive Feedback carried out with the help of optical resonators, which in the elementary version are two coaxial (parallel and along the same axis) located 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 the inverse population is created, is placed between the mirrors. Stimulated radiation passes through the active medium, is amplified, reflected from the mirror, again passes through the medium, and is further amplified. Through a semitransparent mirror, part of the radiation is emitted into external environment, and part is reflected back into the medium and amplified again. Under certain conditions, the photon flux inside the working substance will begin to grow 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 light circles, are in the ground state, i.e., at the lower energy level. Only not a large number of particles represented by dark circles are in an electronically excited state. When the working substance is exposed to a pumping source, the main number of particles goes into an excited state (the number of dark circles has increased), and an inverse population is created. Further (Fig. 2c), spontaneous emission of some particles in an electronically excited state occurs. Radiation directed at an angle to the resonator axis will leave the working substance and the resonator. Radiation that is directed along the axis of the resonator will approach mirror surface.

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

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

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

The exception is semiconductor lasers due to their specificity, since they have everything special: the physics of the processes, the pumping methods, and the design. Semiconductors are crystalline formations. In a separate atom, the energy of an electron takes strictly defined discrete values, and therefore the energy states of an electron in an atom are described in terms 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 band gap. At a semiconductor temperature equal to absolute zero, the valence band must be completely filled with electrons, and the conduction band must 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 the corresponding number of electrons will be lacking 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 generation of an electron-hole pair, with electrons concentrated at the lower edge of the conduction band, and holes at top edge valence zone. Transitions through the forbidden zone are possible not only from the bottom up, but also from the top down. This process is called electron-hole recombination.

When a pure semiconductor is irradiated with light whose photon energy somewhat exceeds the band gap, three types of interaction of light with a substance can occur in a 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 a 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 substance of a semiconductor will be the birth of a secondary photon, identical in its parameters and direction of motion 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, accordingly, a high concentration of holes at the edge of the valence band. For these purposes, pure semiconductor lasers usually use pumping with an electron beam.

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

The properties of doped semiconductors differ significantly from those of undoped, pure semiconductors. This is due to the fact that the 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 it is not far from the lower edge of the conduction band, for f-semiconductors it is near the upper edge of the valence band.

If an electrical 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 p-semiconductor, then under the action electric field electrons from the n-semiconductor and holes from the n-semiconductor will move (inject) into r-p area- transition.

During the recombination of electrons and holes, photons will be emitted, and in the presence of an optical resonator, generation of laser radiation is possible.

The mirrors of the optical resonator are the polished faces of the semiconductor crystal, oriented perpendicularly p-p plane- transition. Such lasers are characterized by miniaturization, since the dimensions of the semiconductor active element can be about 1 mm.

Depending on the feature under consideration, all lasers are subdivided in the following way).

First sign. It is customary to distinguish between laser amplifiers and generators. In amplifiers, weak laser radiation is supplied at the input, and at the output it is correspondingly amplified. There is no external radiation in the generators; it arises in the working substance due to its excitation with the help of 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, arsenide-phosphide-gallium, selenide-lead, etc.).

The method of excitation of the working substance is the third hallmark lasers. Depending on the excitation source, there are lasers with optical pumping, with pumping due to a gas discharge, electronic excitation, charge carrier injection, with thermal, chemical pumping, and some others.

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

According to the nature of the emitted energy, pulsed lasers and continuous-wave lasers 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 get, in fact, discontinuous radiation of different frequencies. Pulsed lasers have big power in a single pulse, reaching 10 W, while their average pulse power, determined by the corresponding formulas, is relatively small. For cw lasers with frequency modulation, the power in the so-called pulse is lower than the power of continuous radiation.

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

high-energy (created flux density radiation power on the surface of an object or biological object - more than 10 W/cm2);

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

low-energy (created flux density radiation power - less than 0.4 W/cm2).

Soft (created energy exposure - 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 the rules for the design and operation of lasers No. 5804-91 ”, according to the degree of danger of the generated radiation for the operating personnel, lasers are divided into four classes.

First class lasers are technical devices, the output collimated (contained in a limited solid angle) radiation of which does not pose a danger when irradiated to the eyes and skin of a person.

Lasers of the second class are devices whose output radiation is dangerous when exposed to the eyes by direct and specularly reflected radiation.

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

Class 4 lasers are devices whose output radiation is dangerous when the skin is exposed to diffusely reflected radiation at a distance of 10 cm from a diffusely reflective surface.

Many radio amateurs at least once in their lives wanted to make a laser with their own hands. It was once believed that it was possible to collect it only in scientific laboratories. Yes, this is true, if we talk about huge laser installations. However, you can assemble a simpler laser, which will also be quite powerful. The idea seems very complicated, but in fact, everything is not at all difficult. In our article with video, we will talk about how you can build your own laser at home.

Powerful do-it-yourself laser

It is very important to follow the basic safety rules. Firstly, when checking the operation of the device or when it is already fully assembled, in no case should you point it at the eyes, at other people or animals. Your laser will be so powerful that it can light a match or even a sheet of paper. Secondly, follow our scheme and then your device will work for a long time and with high quality. Thirdly, do not let children play with it. And finally, store the assembled device in a safe place.

To assemble a laser at home, you will not need too much time and components. So, first you need a DVD-RW drive. It can be both working and non-working. It's not essential. But it is very important that it is a recording device, and not a conventional drive for playing discs. The write speed of the drive must be 16x. It is possible even higher. Next, you need to find a module with a lens, thanks to which the laser can be focused at one point. An old Chinese pointer may well be suitable for this. It is best to use an unnecessary steel lantern as the body of the future laser. The "stuffing" for it will be wires, batteries, resistors and capacitors. Also, do not forget to prepare a soldering iron - assembly will be impossible without it. Now let's see how to assemble a laser from the components described above.

DIY laser circuit

The first thing to do is disassemble the DVD drive. You need to remove the optical part from the drive by disconnecting the cable. Then you will see a laser diode - it should be carefully removed from the case. Remember that a laser diode is extremely sensitive to temperature changes, especially cold. Until you install the diode in the future laser, it is best to rewind the diode leads with a thin wire.

Most often, laser diodes have three terminals. The one in the middle gives a minus. And one of the extreme - plus. You should take two finger batteries and connect to the diode removed from the case using a 5 ohm resistor. In order for the laser to light up, you need to connect the minus of the batteries to the middle terminal of the diode, and the plus to one of the extreme ones. Now you can assemble the laser emitter circuit. By the way, you can power the laser not only from batteries, but also from the accumulator. This is everyone's business.

In order for your device to assemble to a point when turned on, you can use an old Chinese pointer, replacing the laser from the pointer with the one you assembled. The whole structure can be neatly packed into the case. So it will look prettier and last longer. An unnecessary steel lantern can serve as a body. But it can also be almost any capacity. We choose a flashlight not only because it is more durable, but also because your laser will look much more presentable in it.

Thus, you yourself have seen that to assemble a sufficiently powerful laser at home, neither deep knowledge of science nor prohibitively expensive equipment is required. Now you can assemble the laser yourself and use it for its intended purpose.