Each of us kept in the hands of a laser pointer. Despite the decorativeness of the application, it contains the 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 the semiconductor is a written DVD drive of your computer. It has a more powerful laser diode with thermal destructive power.

This allows you to burn a disk layer by applying tracks with digital information on it.

How does the semiconductor laser work?

Devices of this type inexpensive in production, the design is sufficiently massive. The principle of laser (semiconductor) diodes is based on the use classic P-N Transition. It works such a transition as in conventional LEDs.

The difference in the organization of radiation: LEDs emit "spontaneously", and laser diodes "forced."

The general principle of the formation of the so-called "population" of quantum radiation is performed without mirrors. The edges of the crystal are cleaned mechanically, providing the effect of refraction on the ends, akin to the mirror surface.

To obtain various types of radiation, the "homochortage" can be used when both semiconductors are identical, or "heterochor", with different materials Transition.


Actually laser diode is an affordable radio component. It can be bought in stores selling radio components, and can be removed from the old drive DVD-R (DVD-RW).

Important! Even a simple laser used in light pointers can seriously damage the retina.

More powerful installations, with a burning beam, can deprive vision or cause skin burns. Therefore, when working with similar devices, observe maximum caution.

Having at the disposal such a diode, you can easily make a powerful laser with your own hands. In fact, the product may be completely free, or you will be hung for funny money.

Laser do it yourself from dvd drive

To begin with, it is necessary to get the drive itself. It can be removed from the old computer or purchased on the flea market for the symbolic cost.

Would you ever wanted to make a real laser? In fact, it is not as difficult as it may seem. You only need a DVD drive and a bit of girlfriend.

Let's deal with how to make a laser at home. What will you need?

• DVD drive with rewrite function;
• laser pointer;
• colimator to obtain a smooth beam of light;
• several screwdrivers;
• stationery knife;
• scissors for metal;
• soldering iron.

Course of action

We disassemble the DVD-drive and remove the upper panel from it. You are interested in the location of the carriage, because it is there that are guides. Unscrew the bolts and remove the carriage. Do not forget to disable all connectors!

We start the process of disassembling the carriage. It will have 2 diodes. One serves to read, the other is used for burning tracks - it is red. We need the last one.

Usually, this diode is screwed to the board with bolts that should be carefully unscrewed with a small scope. Check it with its performance by connecting to the battery. Gently remove the diode from the housing. Take a purchased collimator, make disassembly. Inside there is a laser diode. I clean it, in his place we put the one that was removed from the drive.

To dismantle, you can apply scolding. If the element is stubborn, it is necessary to apply a sharp knife. Delete this part should be carefully, trying not to cause harm to other components of the board.

The next step is the installation of the diode into the case. It must be glued, using heat-resistant glue. It is important to establish it in the same position, in which stood the previous one. Take a soldering iron, solder wires to an element with mandatory observance of polarity.

Introduced the turn processing laser pointer. We unscrew the lid, remove the components. It may be necessary to reflect the reflector. Make smooth it edges using a file. Do not forget to remove plexiglas.

Remove the batteries, and then insert the design collected earlier to the emitter. Next, we collect a laser pointer in the reverse order, but without using a plastic lens.

Latest strokes

Now you need to return the batteries to their former place and check the created device. Never induce the laser on yourself or people around you and animals. It does not differ in high power, but easily melts a polyethylene package or other stable material. The length of the beam will exceed 100 m, with its help at such a distance you can set fire to the match.

You do not need to collect a laser personally uncomfortable, special tools or things for this. It is important not to forget that this thing is not applicable as a toy. It is dangerous to direct it on the mirrors or other reflective surfaces. If you like to experiment, then this is a great way to create an interesting thing.

Hello ladies and gentlemen. Today I open a series of articles dedicated to powerful lasers, for Habrapoisk says that people are looking for similar articles. I want to tell how to make a pretty powerful laser at home, and also to teach you to use this power not just for the sake of "shifting on the clouds".

A warning!

The article describes the manufacture of a powerful laser (300 mW ~ 500 Chinese pointers), which can harm your health and health surrounding! Be extremely careful! Use special protective glasses and do not direct the laser beam on people and animals!

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

First you need to prepare all components:

• - non-working (or working) DVD-RW drive with recording speed 16x or higher;
• - condensers 100 PF and 100 MF;
• - resistor 2-5 ohms;
• - Three AAA batteries;
• - soldering iron and wires;
• - collimator (or chinese pointer);
• - Steel LED flashlight.

it required minimum For the manufacture of a simple driver model. The driver is, in fact, the fee that will display our laser diode at the desired power. Connect the direct power source to the laser diode is not worth it. The laser diode is needed to feed the current, not the voltage.

The collimator is, in fact, a module with a lens that reduces all radiation into a narrow beam. Ready collimators can be bought in radio logs. There are already a convenient place for the installation of a laser diode immediately, 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 fix, and the collimator body itself is probably made from metallized plastic. So, our diode will be badly cooled. But this is possible. This option can be viewed at the end of the article.

You must first get the laser diode itself. This is a very fragile and small detail of our DVD-RW drive - be careful. A powerful red laser diode is in the carriage of our drive. It is possible to distinguish it from a weak one by a larger radiator than an ordinary IR diode.

It is recommended to use an antistatic bracelet, as the laser diode is very sensitive to static voltage. If there is no bracelet, then you can wrap the dedication of the diode with a thin wire until it is to wait for the installation into the case.

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

Do not confuse polarity! The laser diode will also fail instantly with incorrect polarity of the supply power.

The scheme indicates a condenser 200 MF, however, for portability, 50-100 mf is quite enough.

Before installing a laser diode and collect everything into the case, check the driver's performance. Connect another laser diode (non-working or second, which is from the drive) and measure the current strength by 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 apply even 500mA, but a completely different driver, the manufacture of which I plan to describe in another article.

It looks terrible, but it works!

Aesthetics.

You can boast about the weight with the laser only before the same crazy techno-maniacs, but it is better to collect in a comfortable body for beauty and amenities. It is already better to choose how to like it. I mounted the entire scheme in the usual LED flashlight. Its dimensions do not exceed 10x4cm. However, I do not advise you to wear it with you: if there are never any complaints with the relevant authorities. And it is better to store in a special case, so that a sensitive lens was not dug.

This is an option S. minimal cost - Used collimator from Chinese pointed:

The use of a factory-made module will allow you to obtain these results:

The laser beam is visible in the evening:

And, of course, in the dark:

Maybe.

Yes, I want to tell and show how you can use similar lasers. How to make much more powerful copies that can cut the metal and wood, and not just to wait for the match and melted plastic. How to produce holograms and scan items to obtain 3D Studio Max models. How to make powerful green or blue lasers. The scope of the application of lasers is quite wide, and one article here is not to do.

Attention! Forget about security technician! Lasers are not a toy! Take care of your eyes!

Today we will talk about how to make a self-powerful green or blue laser at home from handicraft materials with your own hands. Also consider drawings, schemes and device of self-made laser pointers with an igniting ray and range 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 basis of the laser is based on the phenomenon of forced (induced) radiation. The radiation of the laser can be continuous, with a constant power, or impulse, achieving extremely large peak capacities. The essence of the phenomenon is that the excited atom is able to emit a photon under the action of another photon without its absorption, if the energy of the latter equals the difference in the energy of the atom levels before and after radiation. In this case, the radiated photon is coherent photon, which caused radiation, that is, it is its exact copy. Thus, light gain occurs. This phenomenon differs from spontaneous radiation in which the emitted photons have random distribution directions, polarization and phase
The likelihood that a random photon will cause induced radiation of an excited atom, exactly equals the probability of absorption of this photone at an atom in an unexcited state. Therefore, it is necessary to enhance light that the excited atoms in the medium were larger than the unexcited. In equilibrium state, this condition is not performed, therefore various pumping systems of the active medium of the laser (optical, electrical, chemical, etc.) are used. In some schemes, the working element of the laser is used as an optical amplifier for radiation from another source.

In the quantum generator there is no external flux of photons, inverse population is created inside it with various pump sources. Depending on sources exist various methods pumping:
optical - powerful flash lamp;
gas discharge in the working substance (active medium);
injection (transfer) current carriers in semiconductor in zone
r-p transitions;
electronic excitation (irradiation in vacuum of a pure semiconductor by electron flow);
heat (heating gas, followed by its sharp cooling;
chemical (use of chemical reaction energy) and some others.

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

Reflecting from the mirrors, the radiation bundle passes the resonator repeatedly, causing induced transitions in it. Radiation can be both continuous and impulse. At the same time, using various devices for quick shutdown and inclusion of feedback and a decrease in the very period of pulse period, it is possible to create conditions for generating a very high power radiation - these are the so-called giant impulses. This mode of operation of the laser is called modulated quality facilities.
The laser beam is a coherent, monochrome, polarized narrow-controlled light stream. In a word, it is a beam of light emitted not only that synchronous sources are also in a very narrow range, and sooner. Summary extremely concentrated light flux.

The radiation generated by the laser is monochromatic, the probability of photon radiation of a certain wavelength is greater than the closely located, associated with the broadening of the spectral line and the likelihood of induced transitions at this frequency also has a maximum. Therefore, gradually in the process of generating photons of this wavelength will dominate all other photons. In addition, due to the special location of the mirrors in laser ray Only those photons that are distributed in the direction parallel to the optical axis of the resonator are preserved at a short distance from her, the remaining photons quickly leave the volume of the resonator. Thus, the laser beam has a very small divergence angle. Finally, the laser beam has strictly defined polarization. To do this, various polarizers are introduced into the resonator, for example, they can serve as flat glass plates, mounted at the corner of the brutener to the direction of the spread of the laser beam.

From how the working body is used in the laser, the working length of its wave is depends, as well as other properties. The working fluid is subjected to "pumping" by energy in order to obtain the effect of inversion of electronic populations, which causes forced radiation of photons and the effect of optical amplification. Simplest form The optical resonator is two parallel mirrors (they can also be four or more) located around the laser working body. The forced radiation of the working body is reflected in the mirrors back and amplified again. Until the output of the outside, the wave can be reflected many times.

So, we formulate a brief condition necessary to create a source of coherent light:

need a working substance with inverse population. Only then can be obtained to gain light due to forced transitions;
the working substance should be placed between the mirrors that exercise feedback;
the amplification given by the working substance, and therefore the number of excited atoms or molecules in the working substance should be greater than the threshold value depending on the reflection coefficient of the output mirror.

The design of the lasers can use the following types of working bodies:

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

Gases. In particular, carbon dioxide, argon, crypton or gas mixes, as in helium neon lasers. "Package" with the energy of these lasers is most often carried out using electrical discharges.
Solid bodies (crystals and windows). The solid material of such working bodies is activated (doped) by adding a small number of chromium ions, neodymium, erbium or titanium. The following crystals are usually used: alumo-yttrium grenades, lithium-yttrium fluoride, sapphire (aluminum oxide) and silicate glass. Solid state lasers are usually "pumped up" with a pulsed lamp or another laser.

Semiconductors. The material in which the transition of electrons between the energy levels may be accompanied by radiation. Semiconductor lasers are very compact, "pumping out" electric shockWhat allows you to use them in household devices, such as CD players.

To turn the amplifier to the generator, you need to organize feedback. In the lasers, it is achieved when placing an active substance between reflective surfaces (mirrors) forming the so-called "open resonator" due to the fact that part of the energies emitted active substance reflected from the mirrors and returns again 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 can be excited only by some certain types of electromagnetic field oscillations, which are called their own oscillations or modes of the resonator.

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

The use of an open resonator (and not closed - a closed metal cavity - characteristic of the microwave range) principal, since in the optical range the resonator with dimensions l \u003d? (L is the characteristic size of the resonator ,? - the wavelength) simply can not be made, and with L \u003e\u003e? A closed resonator loses resonant properties, since 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 (mod) due to the fact that the waves propagating at an angle to the axis of the resonator quickly go beyond its limits, and allows you to save the resonant properties of the resonator at L \u003e\u003e?. However, the resonator in the laser not only provides feedback due to the return reflected from the radiation mirrors into the active substance, but also determines the laser radiation spectrum, its energy characteristics, the direction of radiation.
In the simplest flat wave approximation, the resonance condition in a flat mirror resonator is that a whole number of half-filled on the resonator is laid: L \u003d Q (? / 2) (q is an integer), which leads to expression for the type of oscillation type with the index Q :? Q \u003d Q (C / 2L). As a result, L. radiation spectrum, 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 (component) at a given length L depends on the properties of the active medium, i.e. on the spectrum of spontaneous radiation on the quantum transition used and can reach several tens and hundreds. Under certain conditions, it is possible to select one spectral component, i.e. to carry out a single mode generation mode. The spectral width of each of the components is determined by the loss of energy in the resonator and, first of all, the transmission and absorption of light by mirrors.

The frequency profile of the gain in the working substance (it is determined by the width and form of the working substance line) and the set of own frequencies of the open resonator. For used in open resonator lasers with high qualityness bandwidth of the resonator ?? p, determining the width of the resonant curves of individual mod, and even the distance between adjacent modes ?? H is less than the width of the amplification line ?? H, and even in gas lasers, where broadening lines are the smallest. Therefore, several types of resonator oscillations fall into the gain circuit.

Thus, the laser does not necessarily generate on one frequency, more often, on the contrary, the generation occurs simultaneously on several types of oscillations for which the amplification? More losses in the resonator. In order for the laser to work at one frequency (in one-frequency mode), it is necessary, as a rule, to take special measures (for example, to increase the loss, as shown in Figure 3) or change the distance between the mirrors so that only one falls into the increasing circuit fashion. Since in optics, as noted above ,? H\u003e? P and the generation frequency in the laser is determined in the main frequency of the resonator, then to keep the stable generation frequency, it is necessary to stabilize the resonator. So, if the gain in the working substance overlaps losses in the resonator for certain types of oscillations, they arise to generation. The seed for its occurrence is, as in any generator, noises representing spontaneous radiation in lasers.
In order for the active medium to radiate the coherent monochromatic light, it is necessary to enter feedback, i.e., part of the light-emitted light flux to be directed back to the medium for the implementation of forced radiation. Positive feedback It is carried out using optical resonators, which in the elementary embodiment are two coaxial (parallel and on one axis) of the mirrors, one of which is translucent, and the other is "deaf", that is, completely reflects the light stream. The working substance (active medium), which creates an inverse population, is located between the mirrors. Forced radiation passes through the active medium, enhanced, reflected from the mirror, again passes through the medium and is even more intensified. Through a translucent mirror, part of the radiation is emitted into an external environment, and the part is reflected back to Wednesday and is reinforced again. Under certain conditions, the flow of photons inside the working substance will begin avalanche-like an increase, the generation of monochromatic coherent light will begin.

The principle of operation of the optical resonator, the prevailing number of particles of the working substance, represented by light circles, are in the main state, i.e. at the lower energy level. Only ne. a large number of Particles represented by dark circles are in an electronically excited state. When exposed to a working substance, the pump source is the main amount of particles goes into an excited state (the amount of dark circles has increased), an inverse population has been created. Further (Fig. 2B), spontaneous radiation of some particles in electronically excited state occurs. Radiation directed at an angle to the resonator axis will leave the working substance and the resonator. Radiation, which is directed along the axis of the resonator, will suit the mirror surface.

In a translucent mirror, part of the radiation will pass through it in environmentAnd the part will reflect and again go to the working substance, involving the particles in the excited state in the process of forced radiation.

In the "deaf" mirror, the entire radiation stream will reflect and reappears a working substance, induced by the radiation of all the remaining excited particles, where the situation is reflected when all excited particles have given their storage energy, and at the output of the resonator, a powerful flow of induced radiation was formed on the side of the translucent mirror.

Maintenance constructive elements Laser includes a working substance with certain energy levels of the components of their atoms and molecules, a pump source that creates inverse population in the working substance, and an optical resonator. There are a large number of different lasers, but all of them have the same and moreover a simple principal scheme of the device, which is presented in Fig. 3.

The exceptions are semiconductor lasers due to their specificity, since they have everything special: and process physics, and pumping methods, and design. Semiconductors are crystalline formations. In a separate atom, the electron energy adopts strictly defined discrete values, and therefore the energy states of the electron in the atom are described in the level language. In the semiconductor crystal, energy levels form energy zones. In a pure, non-impurity semiconductor, there are two zones: the so-called valence zone and located above it (on the energy scale) of the conduction zone.

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

As a result of this process, some (relatively small) amount of electrons appear in the conduction zone, and in the valence zone until its full filling will miss the corresponding amount of electrons. The electronic vacancy in the valence zone is represented by a positively charged particle, which is called a hole. The switched electron transition through the prohibited zone from the bottom is considered as the process of generating an electron-hole pair, and the electrons are focused on the lower edge of the conduction zone, and the holes are at the top edge of the valence zone. Transitions through the forbidden zone are possible not only from the bottom up, but from top to bottom. Such a process is called electron recombination and hole.

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

To generate laser radiation, it is necessary to create in the semiconductor inverse population of "working levels" - create a sufficiently high concentration of electrons in the lower edge of the conduction zone and, accordingly, a high concentration of holes at the edge of the valence zone. For these purposes, in pure semiconductor lasers, the fluid flow of electrons is usually used.

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 the 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 semiconductors with impurities differ significantly from the properties of nestless, clean semiconductors. This is due to the fact that atoms of some impurities are easily given to the conduction zone according to one of their electrons. These impurities are called donor, and a semiconductor with such impurities - a P-semi-veter. Atoms of other impurities, by contrast, are captured by one electron from the valence zone, and such impurities are acceptor, and a semiconductor with such impurities - a P-semi-conductor. The energy level of impurity atoms is located inside the prohibited zone: in "-Polponds - not far from the lower edge of the conduction zone, y / ^ - semiconductors - near the upper edge of the valence zone.

If in this area to create an electrical voltage so that from the part of the r-semiconductor there is a positive pole, and from the side of the P-semiconductor is negative, then under the action electric field electrons from the P-semiconductor and holes from / ^ - semiconductor will move (injected) in r-P region - Transition.

When electron recombination and holes, photons will be emitted, and in the presence of an optical resonator, laser radiation is generated.

Optical resonator mirrors are polished semiconductor crystal faces, oriented perpendicular plane R-P - Transition. Such lasers differ in miniature, since the size of the semiconductor active element can be about 1 mm.

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

The first sign. It is customary to distinguish laser amplifiers and generators. In the amplifiers at the inlet, weak laser radiation is supplied, and at the output it is respectively enhanced. There are no external radiation in the generators, it occurs in the working substance due to its excitation using various pump sources. All medical laser devices are generators.

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

The method of excitation of the working substance is the third distinguishing feature of lasers. Depending on the source of excitation, lasers with optical pumping, with pumping due to gas discharge, electronic excitation, injection of charge carriers, with thermal, chemical pumping and some others are distinguished.

The laser radiation spectrum is the following feature of the classification. If the radiation is concentrated in a narrow wavelength interval, it is considered to be monochromatic laser and its technical data indicates a specific wavelength; If in a wide range, then you should consider a laser broadband and indicates the wavelength range.

By the nature of the emitted energy, pulsed lasers and continuous radiation lasers are distinguished. Do not mix the concepts of a pulse laser and a laser with frequency modulation of continuous radiation, since in the second case we get in fact the intermittent radiation of various frequencies. Pulse lasers have a high power in a single pulse reaching 10 W, while their mid-pulse power, determined by the respective formulas, is relatively small. In continuous frequency modulation lasers, the power in the so-called impulse is below the power of continuous radiation.

According to the average output power of the radiation (the following sign of classification), the lasers are divided into:

· High-energy (created flux density. Radiation power on the surface of an object or bio-object is over 10 W / cm2);

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

· Low energy (created flux density. Radiation power is less than 0.4 W / cm2).

· Soft (created energy irradiation - E or power flow 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 standards and rules of the device and operation of lasers No. 5804-91" by the degree of risk of generated radiation for the service personnel, the lasers are divided into four classes.

First-class lasers include such technical devices, the output collimant (concluded in limited bodily corner) radiation of which is not dangerous during the irradiation of the eyes and human skin.

Second-class lasers are devices, the output radiation of which is dangerous when irradiated with the eye direct and mirror reflected radiation.

Third-class lasers are devices, the output radiation of which is a danger upon irradiation of the eyes direct and mirror reflected, as well as diffusely reflected radiation at a distance of 10 cm from the diffuse reflective surface, and (or) when the skin is irradiated with direct and mirror reflected radiation.

Fourth-class lasers are devices, the output radiation of which is danger when irradiating the skin diffusely reflected radiation at a distance of 10 cm from the diffuse reflective surface.

It is possible to create a homemade construction level, when creating light effects when designing a home disco, for an additional rear signal of cars, motorcycles, bicycles, etc.

The laser diode is a semiconductor crystal made in the form of a thin rectangular plate. The beam passes through the collecting lens and represents a thin line, when crossing the surface we see the point. To obtain a visible line, you can install a cylindrical lens before the laser beam. The refracted ray will look like a fan.

The proposed homemade can quickly and cheap even a novice radio amateur.

I made it from the 5MW laser, on the supply voltage of 3V with Aliexpress. Despite the small power of the laser emitter, it is necessary to comply with the elementary safety technique not to direct the beam.

The whole manufacturing process to view in the video:

List of tools and materials
Laser emitter 5MW, 3B (link to laser)
-screwdriver; scissors;
-Paller;
-kembrik; Foil textolite;
-Tweb batteries at1.5V;
-Contentive wires; Battery compartment housing with power button on a naked lamp;
- Spristor on 5Ω;
-Lodiodes with a transparent flask;
- Put fuss.

Step one. Production of a laser board.

From a small piece of foil textolite, we make a scarf for mounting a laser. A piece of tin solder to textolite, having previously bent it on the laser body. Then we insert the laser itself in the clamp (should come tightly). The beam outlet side of the beam solder the LED (if you have a glass transparent tube - you can use a piece of 5mm long) from the back of the board and fading the legs exhibit its position relative to the laser to get a bright and contrasting visible line. It remains to be placed with a laser in a suitable case. In the case of the battery compartment with a switch from a naked lantern, we make a rectangular window. To power this laser emitter, a voltage in 3 V. In the battery case, we set two batteries by 1.5 V. In place of the third battery, we establish our fee with a laser. We turn over the wires, respectively, two batteries and a 5 ohm resistor connect to a push button. If desired, the laser can be powered from the battery and use the down-converter board. I made a 2.8 volt voltage and a current of 15-18 mA to extend the life of the laser diode.

Step second. Production of construction level.
On the basis of this homemade, you can make a laser construction level. The first option is attaching the homemade housing to the industrial level (naturally it is necessary to accurately adjust the position of the beam). The second option to attach to a piece of polyfoam housing of the homemade laser, put this design into a container with water. The water level will always be parallel to the horizon. Laser line position to verify industrial levels. The farther from the surface is the laser of the longer the visible line.

This is the design of the day off. It was interesting to see the refraction of the laser beam with different lenses. How to apply this homemade the case of your choice. The process itself was, at least for me, is interesting. Make an independently such a timer forces beginner without high time and finance. And where to apply them already decide for themselves. A day off and 10 rubles went to all the work (a bag with lasers from Aliexpress 10pcs x 10p. \u003d 100r). I had the rest of the components.