Let's make a laser with our own hands. How to make a powerful laser with your own hands, video Manual laser

Today we will talk about how to make your own powerful green or blue laser at home from improvised materials with your own hands. We will also consider drawings, diagrams and the device of home-made laser pointers with an ignition 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 powers. 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 emission. 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 of 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 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
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, only those photons that propagate in a direction parallel to the optical axis of the resonator at a small distance from it are stored in the laser beam, the rest of the photons quickly leave the resonator volume. 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 not a large number 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, allowing them to be used in consumer devices 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 reflective 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 resonators that provide feedback in the Laser, only 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 its 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 neighboring 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 translucent mirror, part of the radiation is emitted into the external medium, and part is reflected back into the medium and again amplified. 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 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 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 the 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 the 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 the 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 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 at very low temperatures, and the bombardment of semiconductor crystals with an electron beam causes it to be strongly heated. 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 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 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.

The possibility of making something useful from unused or worn-out equipment attracts many home craftsmen. One such useful device is the laser cutter. Having at your disposal a similar apparatus (some even make it from an ordinary laser pointer), you can perform decoration products from various materials.

What materials and mechanisms will be required

To make a simple DIY laser cutter, you will need the following materials and technical devices:

• laser pointer;
• an ordinary flashlight equipped with rechargeable batteries;
• an old writable drive (CD / DVD-RW) equipped with a laser drive (it is not at all necessary that such a drive be in working condition);
• soldering iron;
• set of locksmith tools.

Thus, it is possible to make the simplest device for laser cutting using materials that are easy to find in a home workshop or garage.

The manufacturing process of a simple laser cutter

The main working element of a home-made cutter of the proposed design is the laser element of a computer disk drive. It is necessary to choose a writing drive model because the laser in such devices has a higher power, which allows you to burn tracks on the surface of the disk installed in them. The design of the reader-type disk drive also contains a laser emitter, but its power, used only to illuminate the disk, is low.

The laser emitter, which is equipped with a writing drive, is placed on a special carriage that can move in two directions. To remove the emitter from the carriage, it is necessary to free it from a large number of fasteners and detachable devices. They should be removed very carefully so as not to damage the laser element. In addition to the usual tools, to remove the red laser diode (and to equip the homemade laser cutter, you need it), you will need a soldering iron to carefully release the diode from the existing solder joints. Removing the emitter from seat, care must be taken not to subject it to strong mechanical stress, which can cause it to fail.

The emitter removed from the writing computer disk drive must be installed instead of the LED, which was originally equipped with a laser pointer. To perform this procedure, the laser pointer must be disassembled by dividing its body into two parts. At the top of them is an LED, which should be removed and replaced with a laser emitter from a writing computer drive. When fixing such an emitter in the body of the pointer, you can use glue (it is only important to ensure that the eye of the emitter is located exactly in the center of the hole intended for the beam to exit).

The voltage generated by the power supplies in the laser pointer is not enough to ensure efficient use laser cutter, therefore, it is impractical to use them to equip such a device. For a simple laser cutter, rechargeable batteries used in a conventional electric flashlight are suitable. Thus, by combining the lower part of the flashlight, which houses its rechargeable batteries, with the upper part of the laser pointer, where the emitter from the writing computer drive is already located, you can get a fully functional laser cutter. When performing such a combination, it is very important to observe the polarity batteries, which will feed the emitter with electricity.

Before assembling a home-made hand-held laser cutter of the proposed design, it is necessary to remove the glass installed in it from the tip of the pointer, which will prevent the passage laser beam. In addition, it is necessary to once again check the correct connection of the emitter with the batteries, as well as how accurately its eye is located in relation to the exit hole of the pointer tip. After all structural elements are securely interconnected, you can start using the cutter.

Of course, with the help of such a low-power laser it will not be possible to cut a metal sheet, it is not suitable for woodworking either, but it is suitable for solving simple tasks related to cutting cardboard or thin polymer sheets.

According to the algorithm described above, it is possible to produce more powerful laser ny cutter, somewhat improving the proposed design. In particular, such a device must be additionally equipped with such elements as:

• capacitors, the capacitance of which is 100 pF and 100 mF;
• resistors with parameters 2–5 ohms;
• collimator - a device that is used to collect light rays passing through it into a narrow beam;
• LED flashlight with steel body.

Capacitors and resistors in the design of such a laser cutter are necessary in order to create a driver through which electrical power will be supplied from the batteries to the laser emitter. If you do not use the driver and put the current on the emitter directly, the latter may immediately fail. Despite the higher power, this laser machine for cutting plywood, thick plastic and even more so metal will not work either.

How to make a more powerful machine

Home craftsmen are often interested in more powerful laser machines that you can make yourself. It is quite possible to make a laser for cutting plywood with your own hands and even a laser cutter for metal, but for this you need to acquire the appropriate components. At the same time, it is better to immediately make your own laser machine, which will have decent functionality and work in automatic mode, controlled by an external computer.

Depending on whether you are interested in your own hands or you need an apparatus for working on wood and other materials, you should correctly select the main element of such equipment - a laser emitter, the power of which can be different. Naturally, do-it-yourself laser cutting of plywood is performed by a device of lower power, and a laser for cutting metal must be equipped with an emitter with a power of at least 60 watts.

To make a full-fledged laser machine, including for cutting metal with your own hands, you will need the following Consumables and accessories:

1. a controller that will be responsible for communication between an external computer and the electronic components of the device itself, thereby providing control over its operation;
2. electronic board equipped with an information display;
3. laser (its power is selected depending on the materials for the processing of which the manufactured cutter will be used);
4. stepper motors that will be responsible for moving the desktop of the device in two directions (stepper motors from unused printers or DVD players can be used as such motors);
5. cooling device for the emitter;
6. a DC-DC regulator that will control the amount of voltage supplied to the emitter electronic board;
7. transistors and electronic boards for controlling the cutter stepping motors;
8. Limit switches;
9. pulleys for installing toothed belts and the belts themselves;
10. housing, the size of which allows you to place in it all the elements of the assembled structure;
11. ball bearings of various diameters;
12. bolts, nuts, screws, couplers and collars;
13. wooden planks, from which the working frame of the cutter will be made;
14. metal rods with a diameter of 10 mm, which will be used as guide elements;
15. a computer and a USB cable with which it will connect to the cutter controller;
16. set of locksmith tools.

If you plan to use a laser machine for do-it-yourself metal work, then its design must be reinforced to withstand the weight of the metal sheet being processed.

The presence of a computer and a controller in the design of such a device makes it possible to use it not only as a laser cutter, but also as an engraving machine. With the help of this equipment, the operation of which is controlled by a special computer program, it is possible to apply the most complex patterns and inscriptions on the surface of the workpiece with high accuracy and detail. The corresponding program can be found freely available on the Internet.

By its design, a laser machine that you can make yourself is a shuttle-type device. Its movable and guiding elements are responsible for moving the working head along the X and Y axes. The Z-axis is taken to be the depth to which the workpiece is cut. For the movement of the working head of the laser cutter of the presented design, as mentioned above, stepper motors are responsible, which are fixed on the fixed parts of the device frame and connected to the moving elements using toothed belts.

Sliding support Head with laser and heatsink Carriage assembly

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, it is, if we talk about huge laser systems. 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

DIY laser circuit

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 piece 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. As a housing for the future laser, it is best to use an unnecessary steel lantern. 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 extremes is a 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 battery 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.

THE MOST POWERFUL LASER ON YOUTUBE 10000 mW! SWORD OF THE JEDI!

HOW TO MAKE A CUTTING LASER FROM A DVD DRIVE

Good day, brain engineers! Today I will share with you a guide on how to how to do a laser cutter with a power of 3W and a desktop 1.2x1.2 meters controlled by an Arduino microcontroller.

This brain trick born to create coffee table in pixel art style. It was necessary to cut the material into cubes, but manually it is difficult, and through an online service it is very expensive. Then this 3-watt cutter / engraver for thin materials appeared, I will clarify that industrial cutters have a minimum power of about 400 watts. That is, light materials, such as polystyrene foam, cork sheets, plastic or cardboard, this cutter masters, but only engraves thicker and denser ones.

Step 1: Materials

Arduino R3
Proto Board - display board
stepper motors
3-watt laser
laser cooling
power unit
DC-DC regulator
MOSFET transistor
motor control boards
Limit switches
case (large enough to fit almost all list items)
timing belts
ball bearings 10mm
pulleys for toothed belts
ball bearings
2 boards 135x10x2 cm
2 boards 125x10x2 cm
4 smooth rods with a diameter of 1cm
various bolts and nuts
screws 3.8cm
lubricant
clamps
computer
a circular saw
screwdriver
various drills
sandpaper
vise

Step 2: Wiring Diagram

Laser circuit homemade informatively presented in the photo, there are only a few clarifications.

Stepper motors: I think you noticed that two motors are started from one control board. This is necessary so that one side of the belt does not lag behind the other, that is, the two motors work synchronously and maintain the tension of the toothed belt, which is necessary for high-quality work. crafts.

Laser power: when setting the DC-DC regulator, make sure that the laser is supplied with constant pressure, not exceeding specifications laser, otherwise you will just burn it. My laser is rated at 5V and 2.4A, so the regulator is set to 2A and the voltage is slightly below 5V.

MOSFET transistor: this important detail given brain crafts, since it is this transistor that turns the laser on and off, receiving a signal from the Arduino. Since the current from the microcontroller is very weak, only this MOSFET transistor can perceive it and lock or unlock the laser power circuit, other transistors simply do not respond to such a low-current signal. The MOSFET is mounted between the laser and ground from the DC regulator.

Cooling: When building my laser cutter, I ran into the problem of cooling the laser diode to avoid overheating. Problem solved by installing computer fan, with which the laser functioned perfectly even when working for 9 hours in a row, and a simple radiator could not cope with the task of cooling. I also installed coolers next to the motor control boards, as they also get quite warm, even if the cutter is not working, but just turned on.

Step 3: Assembly

The attached files contain a 3D model of a laser cutter showing the dimensions and assembly principle of the desktop frame.

Shuttle design: it consists of one shuttle responsible for the Y axis, and two twin shuttles responsible for the X axis. The Z axis is not needed, since this is not a 3D printer, but instead the laser will turn on and off alternately, that is, the Z axis is replaced by the pierce depth . I tried to reflect all the dimensions of the shuttle structure in the photo, I will only clarify that all the mounting holes for the rods in the sides and shuttles are 1.2 cm deep.

Guide rods: steel rods (although aluminum is preferable, but steel is easier to get), quite large diameter 1 cm, but this thickness of the rod will avoid sagging. The factory grease was removed from the rods, and the rods themselves were carefully polished with a grinder and sandpaper to perfect smoothness for a good glide. And after grinding, the rods are treated with white lithium grease, which prevents oxidation and improves glide.

Belts and stepper motors: For installation stepper motors and toothed belts I used conventional tools and materials at hand. First, the motors and ball bearings are mounted, and then the belts themselves. As a bracket for the engines, a sheet of metal was used, approximately the same in width and twice as long as the engine itself. This sheet has 4 holes drilled for mounting on the engine and two for mounting on the body homemade, the sheet is bent at an angle of 90 degrees and screwed to the body with self-tapping screws. On the opposite side of the engine mounting point, a bearing system is similarly installed, consisting of a bolt, two ball bearings, a washer and a metal sheet. A hole is drilled in the center of this sheet, with which it is attached to the body, then the sheet is folded in half and a hole is drilled in the center of both halves to install the bearing system. On the engine-bearing pair thus obtained, a toothed belt is put on, which is attached to wooden base shuttle with an ordinary self-tapping screw. This process is more clearly shown in the photo.

Step 4: Soft

Fortunately software for this brain crafts free and open source. Everything you need is in the links below:

In and all that I wanted to tell you about my laser cutter / engraver. Thank you for attention!

good luck homemade!

Sometimes you can make something really incredible and useful from unnecessary things stored at home. Do you have an old DVD-RW (writer) drive lying around at home? We will show you how to make a powerful laser at home by borrowing elements from it.

Safety

The device we end up with is not a harmless toy! Before you make a laser, take care of your safety: hitting the beam in the eyes is detrimental to the retina, especially if the invention is powerful. Therefore, we advise you to carry out all work in special protective glasses that will save your eyesight if something goes wrong and you accidentally direct the laser beam into your eyes or a friend.

When using the laser in the future, remember these simple safety precautions:

• Do not aim the laser beam at flammable or explosive objects.
• Do not shine on reflective surfaces (glasses, mirrors).
• Even a laser beam fired from a distance of up to 100 m poses a danger to the human and animal retinas.

Working with the laser module

The main thing we need is a burner. Note that the higher the write speed, the more powerful our DVD laser will be. It goes without saying that after removing the laser module, the equipment will become inoperative, so disassemble only such a device that you no longer need.

And now we start:

The first part of our work is over. Let's move on to the next important step.

Assembling the device circuit

We need a circuit in order to control the power of our device. Otherwise, it will simply burn out on the first use. You will see the drawing for the laser below.

For our device, hanging mounting is quite suitable. And now let's move on to providing power to a do-it-yourself laser.

Device power supply

At a minimum, we will need 3.7 V. Old batteries from mobile phones, penlight batteries. It is only necessary to connect them in parallel with each other. To check the operation of the device or a stationary laser pointer, a stabilization power supply is suitable.

At this stage, you can already test the operation of the device. Point it at the wall, floor and turn on the power. You should see a bunch of bright reddish color. In the dark, it looks like a powerful infrared flashlight.

You can see that while the glow is far from the laser: the beam is too wide; he asks to be focused. This is what we will do next.

Lens for focusing the laser beam

To adjust the focal length, you can get by with a lens borrowed from the same DVD-RW drive.

Now reconnect the power to the device, directing its light to any surface through this lens. Happened? Then let's move on to final stage work - the placement of all elements in a rigid case.

Case manufacturing

Many, advising how to make a laser, say that the easiest way is to place the module in a case from a small flashlight or a Chinese laser pointer. Where, by the way, there is already a lens. But let's analyze the situation, if neither one nor the other was at hand.

Alternatively, put the elements in aluminum profile. It is easily sawn with a hacksaw, modeled with pliers. You can also add a small finger battery here. How to do this, the photo below will guide you.

Be sure to insulate all contacts. The next step is fixing the lens in the housing. It is easiest to mount it on plasticine - so you can adjust the most successful position. In some cases, a better effect is achieved if you turn the lens towards the laser diode with the convex side.

Turn on the laser and adjust the beam clarity. Once you are satisfied with the results, lock the lens into the housing. Then close it entirely, for example, tightly wrapping it with electrical tape.

How to make a laser: an alternative way

We will offer you another, somewhat different way to make a homemade powerful laser. You will need the following:

• DVD-RW drive with a recording speed of 16x or more.
• Three finger batteries.
• Capacitors 100 mF and 100 pF.
• Resistor from 2 to 5 ohms.
• Wires.
• Soldering iron.
• Laser pointer (or any other collimator - this is the name of the module with a lens).
• LED steel lantern.

Now let's see how to make a laser using this method:

1. Remove the laser module located in the device carriage from the drive in the way already described. Remember to protect it from static electricity by wrapping the outputs with thin wire or wearing an antistatic wrist strap.
2. According to the above scheme, solder the driver - the board that will bring our homemade product to the desired power. Pay great attention to polarity so as not to damage the sensitive laser diode.
3. In this step, we will test the performance of the newly built driver. If the laser module is from a model with a speed of 16x, then a current of 300-350 mA is enough for it. If higher (up to 22x), then stop at 500mA.
4. After you have verified that the driver is suitable, it must be placed in the case. It can be either a base from a Chinese laser pointer with a lens already mounted, or a more suitable housing from an LED flashlight.

Laser testing

And here is what you were interested in how to make a laser for. Let's move on to practical testing of the device. In no case do it at home - only on the street, away from fire and explosive objects, buildings, dead wood, heaps of garbage, etc. For experiments, we need paper, plastic, the same electrical tape, plywood.

So let's start:

• Place a sheet of paper on asphalt, stone, brick. Aim an already well-focused laser beam at it. You will see that after a while the leaf will begin to smoke, and then it will completely light up.
• Now let's move on to plastic - it will also begin to smoke from exposure to a laser beam. We do not recommend conducting such experiments for a long time: combustion products this material very toxic.
• The most interesting experience is with plywood, a flat plank. A focused laser can burn a certain inscription, drawing on it.

Home laser is definitely fine work and whimsical invention. Therefore, it is quite possible that your craft will soon fail, as certain storage and operating conditions are important for it, which cannot be provided at home. The most powerful lasers, which can easily cut metal, can only be obtained in specialized laboratories; naturally, they are not available to amateurs. However, a conventional device is also very dangerous - directed from a long distance into the eyes of a person or animal, close to a flammable object.