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A laser pointer is a fashionable modern gadget of the 21st century!

There are a lot of options for using a laser pointer in everyday life:

• A laser pointer is an inexpensive, portable laser that is similar in appearance and size to a regular pen. It is superior to older pointing devices because only a laser pointer can be used over a distance of several hundred meters, producing a bright spot of light that is very visible to the human eye.
• Laser pointers are widely used in offices for various meetings. Now the presenter does not have to get up and go to the board on which the slides are displayed.
• In some schools, teachers use laser pointers instead of regular wooden ones.
• In many institutes, teachers use only laser pointers during lectures because the board at the institute is much larger than at school.
• In planetariums, green laser pointers have long been used so that even a person not versed in astronomy can show any star and constellation.
• Laser pointers are commonly used in educational settings and business presentations instead of regular pointers. Red laser pointers can be used indoors and outdoors in the evening. Green laser pointers can be used in the same conditions, but green laser pointers, unlike red ones, are clearly visible on the street during the day and at long distances.
• The spot of light produced by a laser pointer attracts cats (and dogs), causing a strong desire to catch it, which is often used by people in games with these pets.
• Green laser pointers can be used for amateur astronomy. On a moonless night, the beam of a green laser pointer can be used to point to stars and constellations.
• A precisely positioned laser pointer can be used as a laser sight to aim firearms or air guns.
• Laser pointers are used in their designs by radio amateurs as an element of communication within visual range.
• A pointer with the collimator removed is used in home holography. This is the only known use of a laser in everyday life, where the most valuable property of a laser is used, which fundamentally distinguishes it from an LED - the monochromaticity of the radiation.
• Psychologists have long proven the influence of a color stimulus on decision making; it is the green color that will create calm and harmony. Your presentations will be more impactful and effective, and you will easily outperform your competitors.
• This convenient and elegant item in a beautiful case can also be a good gift for your loved ones or partners. The compact laser pointer consumes very little battery power and has a long service life of 3000-5000 hours.

As we see nowadays, laser pointers are used everywhere.

The most frequently asked questions and detailed, accurate answers to them:

Question : Tell me, how much does the brightness of a laser pointer beam depend on its power?

Answer : A beam with a power of up to 20-30 mW is quite poorly visible even at night, but from 50 mW the situation changes dramatically and further increase in power no longer gives such stunning indicators. Those. if you had a 5 mW pointer and you changed it to 50 mW, then your joy and surprise will be much greater than if you change the 50 mW to 200 mW. And although the brightness of the beam of 50 mW and 200 mW is not so different, in terms of its burning, incendiary and other similar abilities, 200 mW should not be compared with a 50 milliwatt pointer.

Question : Tell me, to what extent does the power of the pointers written on them correspond to the real state of affairs?

Answer : It often happens that the pointer says 200 mW, but when measuring the power it turns out that it somehow produces 100. Such situations happen quite often. The Chinese are very fond of gluing stickers with a power that is obviously higher than it actually is. Moreover, it is very difficult to distinguish the power of 200mw from 100mw with the naked eye and is only possible if you place two pointers next to each other - 200 and 100 mW. If you just turn on a pointer with a power of 50 mW, give it to a person and say that this pointer has a power of 100 mW - everyone will believe it. Here you need to rely on experience.

Question : There are many stores online that sell these pointers. How are they different from yours? And why are your prices suspiciously cheaper than others?

Answer : When in any store they tell you - “Our laser pointers are the best!” - don’t believe this because in China (where these pointers come from), the laser diodes that are used in these pointers are manufactured at one plant . And all manufacturers of laser pointers (and there are a lot of companies selling them in China) buy these diodes for their products from one manufacturer, and metal cases are not particularly important in these devices. Therefore, our pointers are no better or worse than those in other stores. Absolutely the same.All pointers are the same! Regarding the price, selling laser pointers is not our priority, so we do not set ourselves the goal of making as much money as possible from these laser pointers.

Question : Tell me, is the beam of your green lasers completely visible or just a point?

Answer : During the day, the beam is completely invisible from any pointer! Only a point is visible, the brightness of which, however, depends entirely on the power of the laser diode. But with the onset of twilight, everything depends on the power of the pointer. The greater the laser power, the earlier in the day you will be able to enjoy this spectacle - a bright, juicy beam. Starting with a power of 50 mW, the beam from the pointers will be visible already in the early twilight, and in the dark it will appear as a thick green rope and plow the sky over a radius of several thousand meters. At a power of 150-200 mW, the beam will hit distant clouds, and from 300 mW it will travel many tens of kilometers.

Question : What is the continuous operation time of the laser? Well, that is. Here you press the button and the light shines.

Answer : Firstly, it all depends on the power of the laser pointer, and secondly on the type of batteries or accumulators used. Thirdly, in any case, the manufacturer does not recommend using the pointer continuously for more than 2 minutes, because the laser diode gets very hot during operation and this deteriorates its characteristics, and fourthly, the current flowing through the diode is quite large, and therefore the battery will discharge very quickly soon if you shine your pointer continuously. The recommended operating mode is as follows: We shine for 30 seconds - rest for 20 seconds. or we shine for 20 seconds - rest for 7-10 seconds, so that during this time the diode can cool down and the battery can restore its performance characteristics. In the mode, we light for 5-6 seconds and then rest for 1-2 seconds - continuous operation until the battery is completely discharged. It is this mode that will be the most interesting and optimal for you.

Question : At what power do the “burning” and “incendiary” abilities begin?

Answer : Pointers with a power of up to 100 mW do not burn or set anything on fire. In reality, these properties appear on laser pointers with a power of 200 mW or more. But keep in mind that the further the distance to the object, the weaker these properties are. A green laser from 300 mW, and a violet laser from 200 mW, are already fully burning and setting fire to dark and red objects. Keep in mind that you will not set white objects on fire with any laser pointer! The white color reflects the laser beam and you will not get anything other than a bright spot of light.

Question : How much pointer power is required for wood burning?

Answer : If the tree is painted black, red (or a very dark color), then with a power of 200 mW you will already be able to burn through the tree, and from 300-400 mW the smoke will come out immediately as soon as you start shining the light on the piece of wood.

Laser - acronym for L ight A amplification by S stimulated E mission of R adiation, which literally translates as “light amplification by stimulated emission,” is a device that converts pump energy into the energy of a narrowly directed radiation flux.

There are many different types of lasers. They can be divided into groups according to the pumping source, working fluid, and area of ​​application. Because In this article, lasers will be considered in the context of the safety of working with laser levels and rangefinders, then attention will be paid to such parameters as operating wavelength (nm) and radiation power (mW).

Wavelength , if it is in the visible range, determines the color of the laser beam. Radiation power determines the brightness of the beam, certain capabilities (aiming, demonstrating optical effects, reading barcodes, cutting and welding materials, laser surgery, pumping other lasers).

Radiation in laser levels And rangefinders works like a regular laser pointer - a portable generator of coherent and monochromatic electromagnetic waves in the visible range in the form of a narrow beam. It is made on the basis of a red laser diode, which emits in the range 635-670 nm. Their radiation power does not exceed 1.0 mW.

There are several classifications of the dangers of lasers, which, however, are very similar. Below is the most common international classification.

Class 1 Lasers and laser systems are of very low power and are not capable of creating radiation levels that are dangerous to the human eye. Radiation from Class 1 systems does not pose any danger even under long-term direct eye observation. Class 1 also includes laser devices with higher power lasers that have reliable protection against the beam escaping the housing

Class 2 Low-power visible lasers that can cause damage to the human eye if you specifically look directly at the laser for an extended period of time. These lasers should not be used at head level. Lasers with invisible radiation cannot be classified as Class 2 lasers. Typically, class 2 includes visible lasers with powers up to 1 mW

Class 2a Lasers and laser systems of class 2a, located and secured in such a way that the beam cannot enter the human eye when used correctly

Class 3a Lasers and laser systems that emit visible radiation, which do not usually pose a hazard if the laser is viewed with the naked eye only for a short period (usually due to the blink reflex of the eye). Lasers can be dangerous if viewed through optical instruments (binoculars, telescopes). Typically limited to 5 mW. In many countries, devices of higher classes in some cases require special permission to operate, certification or licensing

Class 3b Lasers and laser systems that pose a hazard when looking directly at the laser. The same applies to the specular reflection of a laser beam. A laser is classified as class 3b if its power is greater than 5 mW

Class 4 Lasers and high power laser systems that are capable of causing severe damage to the human eye in short pulses (< 0,25 с) прямого лазерного луча, а также зеркально или диффузно отражённого. Лазеры и лазерные системы данного класса способны причинить значительное повреждение коже человека, а также оказать опасное воздействие на легко воспламеняющиеся и горючие материалы

Requirements for design and technical characteristics, rules of safe operation and methods of protection from laser radiation on the territory of the Republic of Belarus are regulated by SanPiN 2.2.4.13-2-2006 "Laser radiation and hygienic requirements for the operation of laser products" and STB IEC 60825-1-2011 "Safety laser products. Part 1. Equipment classification and requirements" - a national standard of the Republic of Belarus, which is identical to the international IEC standard.

A significant part of the laser equipment produced in the world is manufactured and labeled in accordance with standards published by the American organization Center for Devices and Radiological Health (CDRH).

Laser levels And rangefinders are laser class 2 in accordance with this classification, which allows their use following the following precautions:
- do not look at the laser beam, the laser beam can damage your eyes, even if you look at it from a great distance;
- do not direct the laser beam at people or animals;
- the laser must be installed above eye level;
- use the device only for measurements;
- do not open the device;
- keep the device out of the reach of children;
- do not use the device near explosive substances.

The structure of green rays is more complex: the first laser, infrared, with a wavelength of 808 nm, shines into an Nd:YVO4 crystal - laser radiation with a wavelength of 1064 nm is obtained. It hits the “frequency doubler” crystal - and it turns out 532 nm.

Some lasers have an infrared filter, but this significantly increases the price of the device, which means it can only be present in expensive models. It is also worth noting that green diodes, devices that emit a green beam, are much more expensive to produce (several times due to the higher number of defects compared to red ones). And the working life of the green diode is much lower. In total, this is reflected in the final cost of the laser level. The result is the following picture. A laser level with a green beam creates projections that are better visible, the service life of such a device is lower, the cost is higher (sometimes one manufacturer sets a price that differs by 1.5-2 times for identical models that differ only in the laser).

It should be noted that according to the characteristics declared by level manufacturers, the power of such a laser is up to 2.7 mW(for red up to 1.0 mW), and safety according to class 3(red has 2).

To summarize, laser green is indeed better visible in daylight conditions than red, but we must not forget that it much more unsafe And unreasonably expensive .

About laser pointers in general: A laser pointer is a portable device that generates a narrowly directed laser beam in the visible light range. In most cases, it is made on the basis of a laser LED, which emits in the range of 473 - 650 nm. The LED radiation is focused into a line due to a biconvex lens. Due to the fact that the diode does not emit directionally, a significant part of the radiation falls on the inner walls of the case and is absorbed. In this regard, the efficiency of the laser pointer is low. However, with high-quality focusing of the beam (which can be done independently by tightening the lens clamping nut), the pointer can be used to conduct experiments with a laser beam (for example, to study interference)
The spot of light produced by a laser pointer attracts cats (and dogs), causing a strong desire to catch it, which is often used by people in games with these pets. We should not forget that a laser pointer beam directed into the eyes of a person or animal can damage the retina.

Using laser pointers: Laser pointers are widely used in offices for various meetings and presentations. In planetariums, green laser pointers have long been used so that even a person not versed in astronomy can show any star and constellation. Also, stargazers can point out any celestial body to their friends.
Psychologists have long proven the influence of a color stimulus on decision-making; green color will create calm and harmony. Your presentations will be more impactful and effective, and you will easily outperform your competitors. This comfortable and elegant item can also be a good gift for your loved ones or partners. The compact laser pointer consumes very little battery power and has a long service life of 3000-5000 hours.

But are they all safe? Can laser beams cause harm? What are the consequences of their harmful actions? Unfortunately, all these questions have to be answered in the affirmative. Contrary to popular belief, laser pointers are not toys, and not only can they have harmful effects on people or animals, but they can also get you in trouble with the law. Just don’t react too emotionally to this and don’t rush to get rid of laser pointers. All you need to do is understand and remember a few rules for using laser devices.

Attention! First of all, never, under any circumstances, point a laser pointer at vehicles with passengers, people or animals. The beam can be distracting and can even temporarily blind a person, which can lead to disaster if a person blinded by the beam is driving a vehicle at a speed of 100 km/h, and there are concrete barriers around. Don't forget about it! If you direct a laser beam at an airplane, you are definitely breaking the law, and subsequently it will be difficult to wriggle out of the accusation. Therefore, always watch where you are pointing the laser pointer beam.

The laser revolution is slowly but surely sweeping the world as more and more people purchase laser pointers for themselves. If you are not already the proud owner of a laser pointer, you are, in a sense, still living in the stone age. Never before have such advanced devices been so accessible (not to mention that many high-energy laser pointers are capable of lighting matches, burning through film, exploding balloons, and the like). The evolution of the laser was rapid and did not stop for a moment. Laser technology covers many applications, from simple presentation pointers to high-powered military installations with concentrated laser beams. It has never been so easy to join the advances in laser technology and buy a laser pointer. The main thing is to never forget about safety rules when using laser devices.

Applications of lasers

The advent of the laser in 1960 marked the beginning of the rapid development of various fields of science and technology. But not only. Lasers led to the emergence of fundamentally new, previously unseen devices and such areas of science as integrated and nonlinear optics, holography, and laser chemistry. The word “laser” itself comes from the English definition “Light Amplification by Stimulated Emission of Radiation”.

Lasers are:

• Gas (argon, helium-neon, carbon monoxide and carbon dioxide, excimer).
• Solid-state (Alexandrite, ruby, crystalline with ytterbium doping, aluminum-yttrium, titanium-sapphire, microchip).
• Semiconductor laser diodes (in pointers, printers, CD/DVD).

With the help of laser technologies, it has become possible to weld, cut, drill, and harden materials without the appearance of internal stress in them, which was impossible to achieve with mechanical processing. The accuracy of such processing literally reaches a micrometer, and the laser does not care what exactly it processes - metal or diamond. In microelectronics, it is preferable not to solder connections, but to weld, and the laser beam does its job perfectly. There is also laser cooling and magnetization. The emitter is still very successfully used in thermonuclear fusion.

Today, lasers are also indispensable in medicine. It is used in surgery, ophthalmology, gynecology, oncology and cosmetic surgery. For example, during operations on the eyeball, a laser is able to weld the detached retina without injuring the eye itself. The laser can burn out both benign and malignant tumors. It is also successfully used in dentistry for teeth whitening and bloodless implantation. And the prospect of using the beam to stop bleeding in people with poor blood clotting is very exciting.

Laser astronomy has also been able to take the quality of its research to a completely different level. For example, with the help of ruby ​​lasers, scientists were able to more accurately determine the distance from the Earth to other cosmic bodies. The accuracy of mapping the surface of planets is now up to 1.5 m. And with the help of semiconductor lasers, communication with satellites is carried out.

A laser is indispensable for geodetic measurements, as well as for recording seismic activity in the Earth’s crust. In geophysics, cloud heights are determined with high accuracy and phenomena such as turbulence and contrails are studied.

• In aviation, laser gyroscopes, altimeters and airspeed meters are used. It is also important that the laser helps to land the plane accurately and correctly, and thereby ensures the safety of the crew and passengers.

  Everyone knows about the laser sight, which increases the shooter's accuracy in hitting the target. The beam is widely used in the armaments of armies around the world. With its help, they not only shoot accurately, but also interfere with the enemy and sniper detection systems, and also develop methods of misleading the enemy.

• Lasers surround us in everyday life. With their help, we listen to CDs, record data, and print information on printers. Cashiers in supermarkets use lasers to read barcodes from products. With its help, subtitles are added to the screen, and teachers use laser pointers to explain the material. And in the evening young people admire enchanting laser shows at the disco.

  Currently at the development stage are technologies such as holographic recording of information and optical methods for its storage and transmission, as well as projection television.

• Features and capabilities of modern laser roulettes and levels

  Today laser precision is needed everywhere

  When laying out plots of land, installing communications, constructing buildings, decorating premises and many other works, effective measuring instruments have recently been often used - a laser tape measure and a level.
  A tape measure is necessary to determine the geometric dimensions of objects with high accuracy. Its operating principle is based on measuring the duration of passage of an impulse to an object and back. Levels are used for internal marking work, marking holes during construction and finishing of premises.

  Functional features of roulettes

  The device consists of a laser, a keyboard, a computing device, and a liquid crystal display. Often, an additional tape measure can be equipped with an optical sight. The emitter can be either rigidly fixed or freely fixed (self-leveling). In addition, modern models have built-in memory and, if necessary, the ability to synchronize with a computer.
  Device models can be classified according to certain criteria. First of all, in terms of measurement range, i.e. the maximum distance that a tape measure can measure with high accuracy. Thus, they produce models whose effective measuring length is no more than 50 meters. They are very convenient for taking measurements indoors and have an error of no more than 1.5 millimeters.

  Additional functions include calculating the area or volume of a room, adding and subtracting values ​​from measurements. Among other things, this type of tape measure is compact, easy to use and produces accurate measurements.

  A device that measures distances up to one hundred and fifty meters is often also called a range finder. Using it, you can take measurements not only indoors, but also in open space, as well as measure distances between various objects. The measurement error is no more than three millimeters.

  In addition, it is necessary to highlight a third model of rangefinders, which have Bluetooth function and, accordingly, have the ability to transmit information wirelessly. They can work with other necessary programs and applications, depending on the required tasks.
  You should also consider a digital tape measure, designed for measuring short distances (up to five meters) with high accuracy. Such a device has a digital display, a function for storing the value of the last measurement taken, automatic shutdown, and is also very compact.
  Electronic tape measures are highly accurate instruments for measuring a wide variety of sizes, both outdoors and indoors. The results of calculations and measurements are displayed almost instantly.
  All models of the described devices are manufactured for industrial or industrial use and household use.

  Main features of laser levels

  Levels are usually produced in two types - a device with an optical system that turns the beam into a plane, and a point plotter. The latest model is often used during finishing and other repair work. This level is effective when laying communications, pouring floors, and laying tiles. A level with built-in prisms that can rotate the beam is more advanced and multifunctional.
  Also levels can be divided into rotary, self-adjusting and building type devices. The latter are used for marking for finishing work, marking holes and other measurements when it is necessary to construct a point at any distance, bypassing existing obstacles.
  The second type of laser level is very convenient, because it saves time on adjusting the rotary base of the level and allows you to adjust vertical or horizontal lines by pressing one button. A rotary level is a device that makes oblique, vertical and horizontal measurements by rotating the beam. It is used more often in open spaces, because its beam is clearly visible at sufficient distances in sunlight. The device has a rotating emitter and two horizontal beams.

  Modern laser tape measures and levels allow you to quickly and very accurately measure various sizes when performing many types of work.

  Partial or complete copying of all components of the site in any form is permitted only when placing a direct active link to the site http://www.lannat.umi.ru

• Laser pointers have been banned in Australia

  Laser pointer key fobs have been banned at airports in the major Australian state of New South Wales. This happened after a series of incidents in which airplane pilots were temporarily blinded by these pointers.

  High-powered pocket lasers, including so-called laser-based "star pointers" used by astronomers, have been blacklisted as a prohibited weapon in New South Wales. Passengers who do not have special permission to carry them will receive 14 years in prison if they attempt to transport such “weapons.”

  "Such irresponsible behavior can lead to dire consequences. It only takes a split second to point a pointer at a pilot's eyes to blind him for some time, during which a terrible catastrophe can occur," says state premier Morris Imma.

  Several pilots have recently reported dangerous laser beams streaking through their cockpits during takeoff and landing. The police responded by organizing a special service to combat “laser lunatics,” as the newspapers dubbed them. The latest incident occurred over the weekend when the pilot of a helicopter heading to Sydney's south was struck by a green laser beam.

  A small laser with blue and green beams can burn through thin plastic, explode an inflated children's balloon, set fire to paper and blind a person. These beams are visible even from the side (of course, not in a vacuum), unlike inexpensive “red” pointers, which reveal themselves only by a bright spot on the target. In general, even small red lasers with a weak beam (usually from 0.5 to 1-2, and less often - up to 5 milliwatts, which are widely sold in stores) are dangerous if they come into direct contact with the eyes. The point here is not so much the power, but the small diameter of the beam, which irreversibly damages individual retinal cells. In many countries their sale is already prohibited.

• A little about laser pointers

  It is difficult to find a person who does not know what a “laser pointer” is. The heyday of the popularity of these devices with a beam power of up to 5 mW in Russia occurred in the 90s - the very red dot resembled the sight of a sniper rifle. Since that time, “laser progress” has stepped far forward. But I didn’t even suspect how much. My acquaintance with the new generation of laser pointers happened by chance, in one of the nightclubs in Beijing. In addition to the DJ, the atmosphere on the dance floor in the club is also created by the VJ - the person who handles the lighting and smoke equipment. Deciding to watch the DJ at work, I saw the VJ take a cigar-sized metal rod from his pocket and point it at the mirrored disco ball. The next second, a thin green beam burst from the tip of the “cigar”, which, colliding with the ball, broke into many smaller beams and illuminated the dance floor. To say that I was surprised is to say nothing. I was shocked. Until this time, I had only seen stationary laser club installations with a similar effect. And here everything fits in a thin “handle”.

  The most important thing about the new generation of “pointers” is that you see not only the point, but the beam itself. It can be of three colors - green, blue or red. In this case, the beam hits a huge distance - up to 5 km. in conditions of urban gas pollution.

  Depending on the power - from 15 mW to 125 mW - you can simply enjoy the spectacle or play pranks, popping, for example, balloons, lighting matches or even cigarettes. The more powerful the beam and the darker the surface the laser hits, the easier it is to achieve a “naughty” effect.

  One of the most famous manufacturers selling lasers online is the Chinese company WickedLasers.com. The prices on the site are fantastic, starting at $150 and ending at $1,700.

  Deciding to search offline, I immediately found an old Nexus model with a 35 mW laser for 200 yuan (about 25 dollars). For this money, in a gift box, I received a laser in black cover in good English (the contents are brief: do not point it at the eyes, change the batteries more often).

  Indeed, it is better to stock up on batteries. At the same time, the most expensive are lithium or alkaline. One pair of batteries will give you 15-20 minutes of bright laser show. Then the beam becomes thinner and disappears.

  Using fresh batteries, the laser easily reached a building two kilometers away. At night the beam is visible clearly and brightly. The spot on the walls is very large. At the same time, a feeling of unreality appears - as if the laser was simply painted onto the surrounding world using Photoshop.

  An incredible effect is achieved, again, in a nightclub. However, the security service immediately responds to unauthorized illumination and asks not to use the laser in the club. In general, they are asking correctly. If a laser hits a visitor's eye, it can cause intense displeasure. Having accidentally hit myself in the eye with a beam from fresh batteries, I felt the hard way that this toy was not a toy at all. Within an hour, vision problems were observed - white spots, blurriness. I was really scared and glad that I didn’t buy the most powerful model. Of course, you can also buy special safety glasses, but they spoil the whole picture - it’s better just not to point the laser at your eyes.

  By the way, there is no need to overuse ordinary “jokes”. I am still ashamed of one incident. Sitting on the balcony and “walking” with a laser around the neighboring house (200 meters from mine), I stopped at one window and drew zigzags on it. The light came on, a Chinese man flew up to the window, began to peer into the darkness, after which he closed the curtains and turned off the light. I wonder how he slept, what he was thinking about?

  Conclusions: an excellent toy, a super find for DJs and VJs, but it can also be useful for professionals. The downside is the short battery life. If you don't live in the Middle Kingdom, the price of the toy will be impressive. At least not a toy at all.

• Types of lasers

  Optically pumped solid-state lasers

  The laser effect in a solid is achieved due to the presence of an impurity in it (for example, chromium oxide in the case of ruby), the concentration of which is a few percent. Neodymium impurities provide laser lasing in many solid structures, of which glass and yttrium aluminum garnet (YAG) are most often used. Such lasers emit short pulses of very high power, the peak value of which is limited from above only by light breakdown in the active medium, causing its damage (for example, local melting). A neodymium glass laser (rod diameter 10 cm) with a pulse duration of one billionth of a second can provide a peak power of about a trillion watts. Longer pulses have lower peak power.

  Gas lasers

  Many gases and gas mixtures, when an electrical discharge occurs in them, begin to generate laser radiation. Their beams are characterized by a very high degree of coherence and low divergence, close to the theoretical limit; in these parameters they compare favorably with solid-state laser beams. To solve applied problems, lasers with a gas mixture as an active medium (carbon dioxide with nitrogen and helium, helium with neon, or krypton with fluorine) are successfully used. The first type of laser emits in the infrared region of the spectrum; in continuous generation mode it has high efficiency and high output power. It is widely used in cutting and welding various materials. A helium-neon laser emits visible (red) light; it is used in many research and educational programs. The fluorine-krypton laser is the most efficient radiation generator in the ultraviolet region of the spectrum.

  Chemical lasers

  Some chemical reactions release a lot of energy, and the end products of such reactions contain enough excited atoms to produce laser lasing. The most promising of lasers of this type seems to be a generator based on hydrogen fluoride, which is formed by the direct interaction of atomic components. Due to the nature of chemical lasers, their continuous generation is difficult. But this drawback is compensated by the advantage of their pulsed modifications - they require low energy costs, and the components of the active medium of chemical lasers are easily transported to remote objects where there are problems with mains power (for example, spacecraft). A hydrogen fluoride laser can emit pulses of very high energy (several thousand joules) with a very modest power supply.

  Semiconductor lasers

  If an electric current is passed through a transistor-type semiconductor structure, a laser effect can be achieved. The dimensions and output power of semiconductor lasers are small, but their efficiency is high. Such lasers are made mainly from gallium arsenide or gallium aluminum arsenide; They are used mainly in communication systems.

  Dye lasers

  Many liquid organic dyes generate laser radiation when pumped by ultraviolet radiation, gas-discharge flash lamps, and continuous-wave (usually gas) lasers. Dye lasers have two important advantages: firstly, they are able to tunable wavelengths and, secondly, they can emit ultrashort pulses - lasting less than one trillionth of a second. In this regard, dye lasers are widely used in spectroscopy methods, including time-resolved spectral analysis.

Laser pointer- a portable quantum-optical generator of coherent and monochromatic electromagnetic waves in the visible range in the form of a narrow beam. In most cases, it is made on the basis of a red laser diode, which emits in the range of 635-670 nm, and a collimator - a biconvex lens for organizing a narrowly directed beam. The rarer blue and purple pointers and, so far (2016), even rarer green ones have a similar device. Until the early to mid-2010s, green laser pointers had a complex structure and consisted of a solid-state laser pumped by an infrared laser diode and a subsequent nonlinear element for doubling the frequency.

The most common are red laser pointers with a power of up to 1-20 mW; pointers up to 100-200 mW are somewhat less common. The most powerful commercially produced pointers: green up to 1W and blue - up to 5 W, green up to 2 W.

• Laser pointer

First, a powerful (usually 200-1000 mW) infrared laser diode with λ = 808 nm is pumped into a neodymium-doped yttrium orthovanadate crystal (Nd:YVO 4), where the radiation is converted to 1064 nm. Then, passing through a crystal of potassium titanyl phosphate (KTiOPO 4, abbreviated KTP), the frequency of the radiation doubles (1064 nm → 532 nm) and visible green light is obtained. The generation and output of green radiation is provided by mirrors, one of which completely reflects radiation with wavelengths of 1064 and 532 nm and completely transmits pump radiation at 808 nm, and the other completely reflects radiation at 1064 nm, but completely transmits 532 nm. The pump radiation is also partially reflected.

In most modern green laser pointers, yttrium vanadate and KTP crystals, together with resonator mirrors, are combined into a so-called “microchip” - a gluing of two crystals with mirrors deposited on the edges. To generate laser radiation, it is sufficient to focus the radiation of a pump laser diode inside the Nd:YVO 4 crystal.

The efficiency of the circuit strongly depends on the pump power and can reach no more than 20%. In addition to green light, such a laser emits significant power in IR at wavelengths of 808 and 1064 nm, so it is necessary to install an infrared filter (IR filter) in such pointers to remove residual IR radiation and avoid damage to vision. In inexpensive versions of green pointers, such a filter may not be installed; in this case, even a pointer with a power of 1-5 mW poses a serious danger to vision, since the power of IR radiation can reach tens of milliwatts. The 1064 nm radiation is focused almost as well as green and poses a hazard if it enters the eye even at long distances, while the 808 nm pump radiation is highly unfocused and not concentrated along the beam, presenting a hazard up to several meters away.

It is worth noting the high energy consumption of green lasers - the current consumption reaches hundreds of milliamps. Since the generation and doubling efficiency increases rapidly with pump power, increasing the output power from 5 to 100 mW requires only approximately doubling the current consumption.

The small size of the green laser pointer does not allow installing a system for stabilizing the temperature of the laser diode and active media. Temperature has a particularly strong effect on the wavelength emitted by a laser diode, which leads to its departure from the maximum of the neodymium absorption line and a drop in output power. This leads to the fact that such pointers operate unstable when the temperature changes. This drawback is partially eliminated by stabilizing the radiation power at the laser output. To do this, a beam splitter is installed at the output (the role of which is played by an IR filter, from which part of the radiation is reflected) and a photodiode, and negative feedback is introduced. The disadvantage of this solution is the possibility of failure of the laser diode with a significant temperature deviation, at which the stabilization system, compensating for the drop in output power, is forced to significantly increase the current through it.

Blue laser pointers (473 nm)

These laser pointers appeared in 2006 and have a similar operating principle to green laser pointers. 473 nm light is typically produced by doubling the frequency of 946 nm laser light. To obtain 946 nm, a crystal of yttrium aluminum garnet with neodymium additives (Nd:YAG) is used.

Blue laser pointers (445 nm)

In these laser pointers, light is emitted from a powerful 1-5 W blue laser diode. Most of these pointers belong to laser hazard class 4 and pose a very serious danger to the eyes and skin, both directly and in the form of radiation scattered by the surface.

Blue pointers have become increasingly widespread due to the serial production of powerful laser diodes, mainly for compact LED projectors, for example Casio Slim.

Purple laser pointers (405nm)

The light in the purple pointers is generated by a laser diode emitting a beam with a wavelength of 405 nm. These lasers are used in Blu-ray Disc recorders. The wavelength of 405 nm is at the limit of the range perceived by human vision and therefore the laser radiation from such pointers appears dim. However, the light from the pointer causes some of the objects it is aimed at to fluoresce, which is brighter to the eye than the brightness of the laser itself. Even the weakest of them are extremely dangerous for the skin and eyes.

Purple laser pointers appeared immediately after the advent of Blu-ray drives, in connection with the start of mass production of 405 nm laser diodes.

Using laser pointers

• Laser pointers are commonly used in educational settings and business presentations in place of regular pointers. They are built into projector remote controls or computer remote controls for presentations. Red laser pointers can be used indoors and outdoors in the evening. Green laser pointers can be used in the same conditions, but, unlike red ones, they are clearly visible on the street during the day and at long distances. The only drawback of laser pointers when pointing at a target is the jerking of the point, since the human hand cannot remain motionless for a long time due to tremor.
• The spot of light produced by a laser pointer attracts cats, dogs and other pets, causing a strong desire to catch it, which is often used by people in games with these pets. However, green laser pointers, due to the significantly higher brightness of the beam, can frighten the animal. We should also not forget that a laser pointer beam directed into the eyes of a person or animal can damage the retina.
• Green laser pointers can be used for amateur astronomy. On a moonless night, the beam of a green laser pointer can be used to point to stars and constellations. Also, a laser pointer can be used to adjust telescopes and to study the shape of the surfaces of telescope mirrors (both by the shadow method and interferometrically).
• A precisely positioned laser pointer can be used as a laser pointer to aim firearms or air guns.
• Laser pointers are used in their designs by radio amateurs as an element of communication within visual range.
• A red pointer with the collimator removed is used in amateur holography. This is one of the few applications of a laser in everyday life, where the most valuable property of a laser is used, which fundamentally distinguishes it from an LED - coherence of radiation. Not all laser pointers have sufficient coherence, so it may be necessary to select a suitable specimen and select the laser diode current. Coherence can be assessed at home, for example, by observing interference using a plane-parallel glass plate 1-2 cm thick.
• In laboratory practice, a laser pointer (especially a green one) is a very useful tool that has many applications - in particular, it can be used to detect in a liquid, gas or any transparent substance (for example, optical glass) small amounts of mechanical impurities or suspensions that are invisible to the naked eye eye. Green, and especially blue or violet pointers in combination with a suitable filter that does not transmit its radiation, make it possible to visually detect weak fluorescence, for example, associated with surface contamination with organic substances.
• A laser pointer, as a source of narrowly directed coherent light, can be used in school physics lessons to demonstrate visual experiments in optics: reflection and refraction of light, diffraction and interference, fluorescence (with a green or blue pointer), light guides, and the like.

Safety

Laser radiation is dangerous if it comes into contact with the eyes.

Conventional laser pointers have a power of 1-5 mW and belong to hazard class 2 - 3A and can pose a danger if the beam is directed into the human eye for a long enough time or through optical instruments. Laser pointers with a power of 50-300 mW belong to class 3B and are capable of causing severe damage to the retina of the eye even when briefly exposed to a direct laser beam, as well as a specular or diffusely reflected one. Even low-power green DPSS pointers use much more powerful IR lasers internally and often do not provide sufficient IR filtering. Such radiation is invisible and because of this is more dangerous for the vision of humans and animals.

At best, laser pointers are only irritating. But the consequences will be dangerous if the beam hits someone's eye or is aimed at a driver or pilot and can distract them or even blind them. In some countries this may result in criminal liability. Thus, in 2015, a US resident was sentenced to 21 months in prison for briefly blinding a police helicopter pilot with a laser pointer. In 2017, a 22-year-old resident of Germany was sentenced to one and a half years in prison for similar actions.

Increasingly numerous “laser incidents” are causing demands in Russia, Canada, the USA and the UK to limit or ban laser pointers. Already in New South Wales there is a fine for possessing a laser pointer, and for “laser attack” - a prison term of up to 14 years.

The use of laser pointers is prohibited by FIFA football stadium safety regulations. One example of the application of this ban was a fine of 50,000

Hi all!
Today is a review of a very useless, but nevertheless interesting thing for some users.
Laser pointer power 5 mW, green glow.
The seller promises ignition with matches. Let's check if this is true?

I'll start the review as usual, with the packaging.
The laser arrived in a large package with several flashlights. The delivery of this parcel is a completely separate story, not without all sorts of incidents))) But I will tell you about this at the end of the review.
I received a complete gift set. There's a box here.


Inside is the laser itself, battery, charger (universal) and keys.


The battery is the famous blue ultrafire))) Unfortunately, it is not famous for its super quality. Well, okay, there is and there is. Moreover, the laser produces excellent light.

The pointer itself is made of aluminum, like the simplest Chinese lanterns. The size is quite large, the body is larger than the Convoy S2+ flashlight.


Additional parts of the set:

A battery with a stated capacity of 4200 mAh. In fact, there are about 700-800. There is no protection. The length is exactly the same as that of an unprotected Samsung.

Charger with Chinese plug, no adapter included. There is a two-color LED. When charging it lights up red, when it's finished it lights up green. It also lights up green if you just insert the battery and do not plug the plug into the socket.


The simplest cheap charger for almost any lithium battery. The charge is exactly up to 4.2, everything is fair here. But I wouldn’t recommend leaving this one unattended, and even with a complete battery.

The laser has a side button. There is a lock at the back, closing which interrupts the circuit and the laser will not light up. Everything works here without any problems!

It can be disassembled into several components.

Laser diode:


By the way, with the lens removed, the laser beam will not work. The light spot is quite wide.
It also provides for the use of a small 16340 or 18350 battery. With such a battery, the pointer becomes noticeably more compact. This is achieved by unscrewing the central tube. In addition, my MECO ()16340 batteries have an honest capacity of approximately 700 mAh, which is almost the same as the supplied battery.

This pointer has a focusing ring that allows you to make the beam thinner.


But no matter how I tried to focus the beam, set something on fire, or burst a balloon, I failed. I also shined these lasers directly into the eye of the old webcam. It was not possible to disable it, but after the beam hits, the matrix catches the “bunnies” for a few seconds))) So it won’t be possible to spoil the CCTV cameras either, well, maybe only temporarily.

And of course, let's see how it shines)))
I have had lasers hundreds of times more powerful than this (), yet the green color is perceived by the eye much better than blue, and this green feels brighter than that blue hyperboloid (as some of the commentators dubbed it). In general, the WOW effect is guaranteed for those unfamiliar with the topic. I guarantee it!








Also, using a long shutter speed on the camera, you can draw letters and all sorts of shapes.

This is such a toy. I don't even know where to use it. You can’t give it to children without accidentally shining it into their eyes.
Oh yes! Cats run after the beam like crazy))) But again, there is a danger of getting into the eyes. Be careful!!!

Well, at the end of the review I will tell the story of how this pointer came to me, and not only that.
Somewhere in the middle of summer, a girl from the TOMTOP store wrote to me on VK and offered products for review. I don’t even remember what she offered, but some kind of crap, and I asked for something else, for example, flashlights. She agreed, saying that I could choose flashlights for 40 bucks. No sooner said than done))) The very next day I provided her with a list. It included two LIXADA flashlights, models X5 and X3, several 16340 batteries, and to get up to 40 bucks I asked for this pointer))) By the way, it also belongs to this brand, as the sticker with the inscription Lixada tells us. Since I'm still looking for inexpensive but high-quality flashlights, I decided to check out this manufacturer. Although Aliexpress is full of such pointers and without stickers. Well, okay, that's not the most interesting thing.
A week later I was given a track. Well, I began to wait. The parcel arrived, but got stuck at customs. A couple of weeks later, I asked that girl if everything was okay, to which she replied that the parcel was turned away at customs at the airport due to the presence of those same 16,340 batteries. China Post by the way.
After some time, she wrote that she had received the parcel back and re-sent it, only by Turkish Post, and also issued a track. And what do you think? This exact situation happened this time too))) All because I am a winner in life)))
It was around August, and I safely gave up on it all. And then two weeks ago they called me from DHL and asked what time would be convenient for me to receive the parcel. I was surprised twice at once, since I had never ordered anything through this company, and that in my muhosransk there is actually an office of theirs))) Well, in general, as you already understood, this package turned out to be from Tomtop, and contained two lanterns and this pointer.

Two central ones, if that.

The lanterns turned out to be very decent, by the way.

But the adventures didn’t end there either.
While the package was wandering, these lights disappeared from the site))) Now the old links give me a 404 error. And I don’t know what to do. I’ve been writing to that girl for three days, and there’s still silence. Although the reviews are almost ready, there are no links.
This is the story))) Believe it or not.

Something like this. To summarize, I will say that the toy under review is specific, and many people have it (or have ever had it). Why do I need it? I don't know myself. I wouldn't buy it for money. Only needed for the WOW effect))) There are few applications in everyday life.
But nevertheless, the pointer ended up in my hands and I told about it “from my own bell tower”))) Thank you all for watching the review! Constructive criticism is welcome! If there is anything I haven’t completed, ask, I will answer everyone!
See you soon!

IMPORTANT ADDENDUM!
The laser still burns! Just recorded a video:

Due to my illiteracy in this matter, I did not immediately figure out how to focus the beam so that the match would light.
I furiously upvote the user directly for the advice he provided!
I apologize)))

The product was provided for writing a review by the store. The review was published in accordance with clause 18 of the Site Rules.

I'm planning to buy +5 Add to favorites I liked the review +19 +43