Creatively adopted the column lens array and dual-target docking, multi-target tandem, dual-range amplification, long-distance multi-target tandem spatial beam limiting and other novel and unique designs, and established a series of effective target, X-ray reflector precision adjustment and focal line precise collimation of the technological means in the medium-sized Shenguang Ⅰ device in the series of experiments of the class of Ne germanium, and successfully obtained the intensity of gain saturation, directionality close to the diffraction limit of the soft X-ray laser output, the intensity of the soft X-ray laser output, and the directionality of the soft X-ray laser output. In a series of Ne-like germanium experiments carried out in the medium-sized Shenlight Ⅰ device, a soft X-ray laser output with intensity saturated with gain and directivity close to the diffraction limit was successfully obtained. Then, in the slightly larger Scandinavian Ⅱ device, a Ni-like soft X-ray laser was obtained at a wavelength close to the water window by using a creative focal line overlap scheme with a pre-main pulse laser drive. Two rounds of collaborative experiments on the D.E. Gekko device at the Institute of Laser Engineering, Osaka University, Japan, successfully promoted the application of uniform line focusing and dual-target docking techniques to obtain high-intensity Ni-like ion soft X-ray laser output.
Laser technology applications
Laser processing technology is the use of laser beams and material interaction characteristics of the material (including metal and non-metal) for cutting, welding, surface treatment, punching, micromachining, and as a source of light, identification of objects, etc., a technology, the traditional application of the largest areas of laser processing technology. Laser technology is involved in light, machine, electricity, materials and testing and other disciplines of a comprehensive technology, traditionally, the scope of its research can generally be divided into:
1. Laser processing system. Including lasers, light guide system, processing machine tools, control systems and detection systems.
2. Laser processing process. Including cutting, welding, surface treatment, punching, marking, scribing, fine-tuning and other various processing techniques.
Laser welding: auto body thick and thin plates, automotive parts, lithium batteries, pacemakers, sealed relays and other sealed devices, as well as a variety of devices that do not allow welding pollution and deformation. Currently used lasers are YAG lasers, CO2 lasers and semiconductor pump lasers.
Laser cutting: automotive industry, computers, electrical enclosures, wood knife mold industry, a variety of metal parts and special materials, cutting, circular saw blades, acrylic, spring gaskets, 2mm or less of the electronic parts with copper, some metal mesh board, steel tubes, tin-plated iron plate, lead-plated steel, phosphor bronze, bakelite, thin aluminum alloys, quartz glass, silicone rubber, alumina ceramic pieces less than 1mm, Titanium alloy used in the aerospace industry and so on. The lasers used are YAG lasers and CO2 lasers.
Laser marking: in a variety of materials and almost all industries are widely used, the current use of lasers are YAG lasers, CO2 lasers and semiconductor pump lasers.
Laser perforation: Laser perforation is mainly used in aerospace, automotive manufacturing, electronic instrumentation, chemical and other industries. The rapid development of laser perforation, mainly in the perforation of the average output power of the YAG laser has been increased from 5 years ago 400w to 800w to 1000w. Domestic more mature laser perforation applications are in the production of synthetic diamond and natural diamond wire drawing molds and clocks and instrumentation gemstone bearings, aircraft blades, multi-layer printed circuit boards and other industries in the production. The lasers currently used are mostly YAG lasers, CO2 lasers, but also some excimer lasers, isotope lasers and semiconductor pumped lasers.
Laser heat treatment: widely used in the automotive industry, such as cylinder liners, crankshafts, piston rings, commutators, gears and other parts of the heat treatment, but also in the aerospace, machine tool industry and other machinery industry is also widely used. China's laser heat treatment applications are far more extensive than abroad. The current use of lasers are mostly YAG lasers, CO2 lasers are mainly.
Laser rapid prototyping: laser processing technology and computer numerical control technology and flexible manufacturing technology combined and formed. Mostly used in molds and models industry. The current use of the laser is mostly YAG laser, CO2 laser-based.
Laser coating: widely used in the aerospace, mold and die and electromechanical industries. Currently used lasers are mostly high-power YAG lasers, CO2 lasers.
Laser applications in medicine
Laser systems used in dentistry
Based on the different roles of lasers in dental applications, divided into several different laser systems. One of the important features that distinguish lasers is: the wavelength of light, different wavelengths of laser light have different effects on tissues, in the visible and near-infrared spectral range of light, light absorption is low, penetration is strong, and can penetrate into the deeper parts of the dental tissues, such as argon ion lasers, diode lasers, or Nd: YAG lasers (as shown in Figure 1). While Er: YAG laser and CO, laser light penetration is poor, can only penetrate the dental tissue about 0.01 mm. Distinguish between the important characteristics of the laser is: the intensity of the laser (i.e., power), such as diode laser used in diagnostics, its intensity is only a few milliwatts, it is sometimes available in the laser display.
Lasers used for therapeutic purposes are usually of moderate intensity of a few watts. The effect of the laser on the tissue also depends on how the laser pulses are emitted. Lasers that are emitted in typical continuous pulses are: argon ion lasers, diode lasers, CO2, lasers; lasers that are emitted in short pulses are: Er:YAG lasers or many Nd:YAG lasers, and short pulses of lasers can be as intense (i.e., as powerful) as 1,000 watts or more, which is a high intensity, light-absorbing lasers, which are also high, are only suitable for removing hard tissue.
Laser applications in the diagnosis of dental caries
1. Demineralization, shallow caries
2. Hidden caries
Laser applications in treatment
1. Cutting
2. Polymerization of fillings, cavity treatment
Laser aesthetics
(1) Lasers are becoming more and more popular in the aesthetic world. Laser is through the generation of high energy, focusing precision, with a certain penetrating power of monochromatic light, the action of the human body tissues and the local production of high heat so as to achieve the purpose of removing or destroying the target tissues, a variety of different wavelengths of pulsed laser can be treated for a variety of vascular skin diseases and pigmentation, such as nevus of ota, nevus erythematosus, freckles, age spots, capillary dilatation, etc., and to remove the tattoos, eyeliner, eyebrow washing, treatment of In recent years, some new laser instruments, high-energy super-pulse CO2 laser, erbium laser for wrinkles, dermabrasion, skin resurfacing, treatment of snoring, whitening teeth, etc., achieved good results for laser surgery to open up more and more broad areas.
(2) Laser surgery has the superiority of traditional surgery can not be compared. First of all, laser surgery does not require hospitalization, small surgical incisions, intraoperative bleeding, light trauma, no scar. For example: the treatment of under-eye bags traditional surgical method exists due to the peeling of a wide range, intraoperative bleeding, post-operative healing is slow, easy to form a scar and other shortcomings, and the application of high-energy ultra-pulse CO2 laser for the treatment of under-eye bags, it does not bleed during the operation without sutures, does not affect the normal work, the surgical part of the oedema is light, fast recovery, no scar and so on the advantages of the traditional surgery, so that the traditional surgery can not be compared. Some endoscopic surgeries that cannot be performed due to heavy bleeding can be completed by laser cutting instead. (Note: there is a certain scope of adaptation)
(3) laser in the vascular skin diseases and pigmentation treatment with excellent results. The use of pulsed dye laser in the treatment of nevus erythematosus has remarkable efficacy with little damage to the surrounding tissues and almost no scarring. Its appearance has become a revolution in the history of nevus bright red treatment, because in the history of nevus bright red treatment, radiation, freezing, electrocautery, surgery and other methods, the incidence of scarring is high, and pigment loss or hyperpigmentation often occurs. Laser treatment of vascular skin disease uses the selective absorption of oxygen-containing hemoglobin to a certain wavelength of laser light, resulting in a high degree of destruction of vascular tissues, which is highly precise and safe, and does not affect the surrounding neighboring tissues. Therefore, laser treatment of capillary dilatation is also effective.
In addition, due to the successive introduction of variable pulse lasers, the removal of unsatisfactory tattoos, as well as the treatment of various pigmented skin diseases such as nevus of Ota, age spots and so on, has been a major breakthrough. This kind of laser according to the theory of selective photothermal effect, (i.e., different wavelengths of laser light can selectively act on different colors of skin damage), using its strong instantaneous power, highly concentrated radiation energy and pigment selective, very short pulse width, so that the laser energy focused on the role of pigment particles, will be directly vaporized, broken, discharged out of the body through the lymphatic tissues without affecting the surrounding normal tissues, and its curative effect of It is also known for its efficacy, safety and reliability, no scar, and little pain.
(4) Laser surgery has created a new era of medical aesthetics. High-energy super-pulse CO2 laser skin resurfacing peeling pioneered the new technology of cosmetic surgery. It uses high energy, very short pulse of laser, so that the aging, damaged skin tissue is instantly vaporized, without injuring the surrounding tissues, the treatment process is almost no bleeding, and can accurately control the depth of action. Its effect has been fully affirmed by the international medical cosmetology industry, and it is regarded as "creating a new era of medical cosmetology"; in addition, there are high-energy super-pulse CO2 laser for treating under-eye bags, snoring, and even laser teeth whitening, etc., which creates one miracle after another with its safe and precise efficacy and easy and fast treatment in the medical cosmetology industry. Laser cosmetology has made a big step forward in medical cosmetology and has given a newer connotation to medical cosmetology.
Laser cooling
Laser cooling is a high-tech technology that utilizes the interaction between lasers and atoms to decelerate the movement of atoms in order to obtain ultra-low temperature atoms. The main purpose of this important technology in the early days was to accurately measure various atomic parameters for high-resolution laser spectroscopy and ultra-high-precision quantum frequency scales (atomic clocks), but later it became a key experimental method to realize the Bose-Einstein condensation of atoms. Although it was noted as early as the beginning of the 20th century that light had a radiative pressure effect on atoms, it was only after the invention of lasers that the technique of using light pressure to change the speed of atoms was developed. It has been found that when atoms move in a pair of laser beams with frequencies slightly lower than the difference between the atomic jump energy levels and propagating in opposite directions, due to the Doppler effect, atoms tend to absorb photons in the opposite direction of the atomic motion, while the absorption of photons traveling in the same direction as theirs is less likely; the absorbed photons will be isotropically and spontaneously radiated. On average, it seems that the net effect of the two laser beams is to produce a damping force opposite to the direction of atomic motion, thus slowing down the motion of atoms (i.e., cooling down). 1985 Phillips of the National Institute of Standards and Technology (willam D. Phillips) and Stanford University's Lemon Moon Chu (Steven Chu) was the first to realize the experiments on laser cooling of atoms, and obtained very low temperature (24 μK) sodium atom gas. They further cooled the atoms by using a three-dimensional laser beam to form magneto-optical lectures that imprisoned the atoms in a small region of space, obtaining even lower-temperature "optical goo". After that, many new methods of laser cooling have emerged, the more famous of which are "velocity-selective coherent Buju imprisonment" and "Raman cooling", the former by the French Ecole Normale Supérieure de Paris, Claud Cohen-Dannodji (Claud Cohen- Tannodji) proposed. Tannodji, the former by Claud Cohen- Tannodji at the école Normale Supérieure de Paris, France, and the latter by Mowen Zhu, who used this technique to obtain very low temperatures below the recoil limit of photons, respectively. Since then, a series of cooling techniques combining magnetic fields and lasers have been developed, including polarization gradient cooling, magnetic induction cooling, and so on. The trio of Mowen Zhu, Kochen Danoki and Phillips were awarded the 1997 Nobel Prize in Physics for this work. Laser cooling has many applications, such as: atomic optics, atomic etching, atomic clocks, optical lattices, optical tweezers, Bose-Einstein condensation, atomic lasers, high-resolution spectroscopy, and fundamental studies of the interaction between light and matter.
Laser spectroscopy
Laser spectroscopy (laser spectra) spectroscopic technology using a laser as a light source. Compared with ordinary light sources, laser light source has good monochromaticity, high brightness, strong directionality and coherence, etc. It is an ideal light source used to study the interaction between light and matter, so as to identify the structure, composition, state and change of matter and its system. The emergence of lasers has greatly improved the original spectroscopic techniques in terms of sensitivity and resolution. Since lasers with extremely high intensity and narrow pulse widths have become available, the observation of multiphoton processes, nonlinear photochemical processes, and the relaxation of molecules after they have been excited has become possible and has developed into a new spectroscopic technique, respectively. Laser spectroscopy has become a research field closely related to physics, chemistry, biology and materials science.
Laser sensor
Laser sensor (laser transducer) using laser technology for measurement of the sensor. It consists of a laser, laser detector and measurement circuit. Laser sensor is a new type of measuring instrument, its advantages are able to realize non-contact long-distance measurement, fast speed, high precision, large range, anti-light, electrical interference ability.
Laser radar
Laser radar (laser radar) refers to the use of lasers as a radiation source of radar. Lidar is a combination of laser technology and radar technology products. By the transmitter, antenna, receiver, tracking frame and information processing and other components. The transmitter is a variety of forms of lasers, such as carbon dioxide lasers, neodymium-doped yttrium aluminum garnet lasers, semiconductor lasers and wavelength tunable solid-state lasers, etc.; antenna is an optical telescope; the receiver uses a variety of forms of photoelectric detectors, such as photomultiplier tubes, semiconductor photoelectric diodes, avalanche photoelectric diodes, infrared and visible multiple detector devices. Lidar uses pulse or continuous wave 2 kinds of work, detection method is divided into direct detection and differential detection.
Laser weapon
Laser weapon is a kind of directional energy weapon that uses laser beams emitted in a directional direction to directly damage or disable the target. According to the different operational purposes, laser weapons can be divided into two categories: tactical laser weapons and strategic laser weapons. The weapon system mainly consists of lasers and tracking, targeting, launching devices and other components, and the lasers usually used at present are chemical lasers, solid-state lasers, CO2 lasers and so on. Laser weapons have the advantages of fast attack speed, flexible steering, precise strikes, and no electromagnetic interference, but there are also weaknesses such as susceptibility to weather and environmental influences. Laser weapons have more than 30 years of development history, and its key technologies have made breakthroughs, the United States, Russia, France, Israel and other countries have successfully conducted a variety of laser targeting tests. At present, low-energy laser weapons have been put into use, mainly used to interfere with and blind photoelectric sensors at a relatively close distance, as well as attacking the human eye and some enhanced observation equipment; high-energy laser weapons are mainly chemical lasers, according to the existing level, in the next 5-10 years can be expected to be deployed on the ground and air platforms for use in tactical air defense, anti-missile and anti-satellite warfare, and so on. .
Classification of Laser Weapons
Lasers with different power densities, different output waveforms, and different wavelengths will produce different killing and destructive effects when interacting with different target materials. With the laser as a "dead light" weapon, not like in laser processing with the help of lens focusing, and must greatly increase the output power of the laser, the combat can be based on different needs to choose the appropriate laser. At present, a wide variety of lasers, different names, there is the volume of a building occupied by a whole, the power of trillions of watts, used to trigger nuclear fusion laser, there are smaller than a person's fingernail, the output power of only a few milliwatts, used for optoelectronic communications semiconductor lasers. According to the working medium, there are solid lasers, liquid lasers and molecular, ionic and excimer gas lasers. Meanwhile, according to its launch location can be divided into space-based, land-based, shipborne. Vehicle and airborne and other types, according to its use can also be divided into tactical and strategic types of two categories.
1. Tactical laser weapons
Tactical laser weapons is the use of laser as energy, is like conventional weapons to directly kill and maim enemy personnel, destroy tanks, aircraft, etc., the strike distance is generally up to 20 kilometers. The main representatives of this weapon are laser guns and laser cannons, which can send out a very strong laser beam to combat the enemy. 1978 March, the world's first laser gun in the United States was born. The style of laser gun is not much different from that of ordinary rifle, which mainly consists of four main parts: laser, exciter, striker and stock. At present, foreign countries have a ruby pocket laser gun, shape and size with the United States Parker pen equivalent. But it can be a few meters away from people burn clothes, burn through the flesh, and no sound, unknowingly causing death, and can be in a certain distance, so that the gunpowder explosion, so that night vision, infrared or laser rangefinders and other photoelectric equipment failure. There are also seven kinds of slightly larger weight and machine gun similar to the compact laser gun, can penetrate the copper helmet, at a distance of 1500 meters to burn the skin and flesh, blinding eyes and so on.
Tactical laser weapons "eye gouging" can not only cause the aircraft out of control, the destruction of people, or make the gunner incapacitated, and because of the soldiers do not know the other side of the laser weapons will appear when and where, often subject to heavy psychological pressure. Therefore, laser weapons and conventional weapons do not have a deterrent effect. 1982 British-Argentine war in the Isle of Man, the United Kingdom in the aircraft carriers and various types of frigates on the installation of laser blinding weapons, has made Argentina's aircraft out of control, crashed or mistakenly into the British army shooting fire network.
2. Strategic Laser Weapons
Strategic laser weapons can attack thousands of kilometers away from the intercontinental missiles; can attack the reconnaissance satellites and communications satellites in space. For example, in November 1975, the United States of America's two reconnaissance satellites to monitor the missile silos flying over Siberia, the Soviet Union's "anti-satellite" land-based laser weapons hit, and become "blind". Therefore, high-base, high-energy laser weapons are one of the ideal weapons for seizing the advantage of the cosmic space, which is also the fundamental reason for the fierce competition among the military powers at great expense. According to foreign publications, since the 1970s, the United States and Russia are respectively in the name of a variety of dozens of anti-satellite laser weapon tests.
At present, the development of anti-strategic missile laser weapons types of chemical lasers, excimer lasers, free electron lasers and tuned ray lasers. For example, free electron lasers have the advantages of high output power, good beam quality, high conversion efficiency, and wide tunable range. However, free-electron lasers are bulky and only suitable for installation on the ground for use in land-based laser weapons. In combat, the strong laser beam is first shot to the interrupter mirror in high orbit in space. The interrupting mirror reflects the laser beam to the combat reflector in low orbit, which then aims the laser beam at the target to carry out the attack. With these two reflections, a ground-based free-electron laser weapon can attack strategic missiles launched from anywhere in the world.
High-based high-energy laser weapons are a combination of high-energy laser weapons and spacecraft. When this laser travels along the space orbit goo, once found each other target, can be put into combat. Because it is deployed in the cosmic space, living high down, broad field of vision, is like a tiger with wings. In actual combat, it can be used on the other side of the air target to implement lightning attacks to destroy each other's reconnaissance satellites, early warning satellites, communications satellites, weather satellites, and even the other side of the intercontinental missiles can be destroyed in the boosting stage of the ascent.
Laser glass
Laser glass is a glass-based solid laser material. It is widely used in all types of solid-state laser light sources and has become the primary laser material for high-power and high-energy lasers.
Laser glass consists of two parts: matrix glass and activation ions. Various physicochemical properties of laser glass are mainly determined by the matrix glass, while its spectral properties are mainly determined by the activation ion. However, the matrix glass and activation ions interact with each other, so the activation ions have a certain effect on the physicochemical properties of the laser glass, while the matrix glass on its spectral properties of the impact is sometimes quite important.
Laser history
In 1958, the American scientists Shollo and Towns discovered a magical phenomenon: when they shine the light emitted by the inner light bulb on a rare earth crystal, the molecules of the crystal will emit brightly colored, strong light that will always be clustered together. Based on this phenomenon, they formulated the "Laser Principle", which states that matter, when excited by energy at the same frequency as the intrinsic oscillation frequency of its molecules, produces this kind of non-dispersive bright light, the laser. This led to the discovery of an important paper.
After the publication of the research results of Xiao Luo and Towns, scientists from various countries have put forward a variety of experimental programs, but were unsuccessful. 1960 May 15, the United States of America, California Hughes Laboratory scientists Meyman announced the acquisition of the wavelength of 0.6943 microns of laser light, this is the first beam of laser light ever obtained by mankind, and Meyman has become the world's first to bring the laser into the practical field of scientists. The first scientist in the world to introduce lasers into the realm of practicality.
On July 7, 1960, Meyman announced the birth of the world's first laser, Meyman's scheme was to use a high-intensity flash tube to stimulate chromium atoms in a ruby-colored crystal to produce a thin column of red light that was quite concentrated, and which, when directed at a certain point, could be made to reach temperatures higher than those on the surface of the Sun.
The Soviet scientist H.Γ. Basov invented the semiconductor laser in 1960. The structure of a semiconductor laser usually consists of a P layer, an N layer, and an active layer forming a double heterojunction. It is characterized by small size, high coupling efficiency, fast response speed, wavelength and size adapted to the size of the optical fiber, direct modulation, and good coherence.
China's laser research new advances in military science of great significance
According to the Chinese Academy of Sciences news, after the Chinese Academy of Sciences Institute of Physics Wang Shuduo research and development group of personnel efforts, the first time to achieve a large area of excimer laser energy direct measurement of the effective measurement of the diameter of up to 100mm, in the size of pyroelectric-type laser detector for the world's largest. After cooperation with the relevant experts of the China Academy of Atomic Energy Science and the tests conducted in the National Laboratory showed that this system in different energy regions (10-20J and 100-200mJ) have reached the expected technical specifications.
According to reports, laser fusion research is a promising energy development topic, laser controlled thermonuclear fusion reaction will certainly bring a new twist to human life. Laser fusion in military science research is also of great significance. In laser fusion experiments, especially in indirect-drive fusion research, high X-ray conversion efficiency, good radiation transport environment, and optimal radiation drive field are being pursued in order to produce a strong radiation drive field. During these studies, it is very important to directly monitor and study the energy of the excimer laser.
The results of this research show that the research and development of the project in addition to the strength of the developed product market continues to develop, the country is developing the application of the demand for the project also has the ability to undertake and develop.
"Laser revolution" is of great significance
In modern society, the role of information is becoming increasingly important, who masters the information more quickly, more accurate, more abundant, who will be more in control of the right to take the initiative, there are more opportunities for success. The emergence of laser triggered an information revolution, from VCD, DVD discs to laser photolithography, the use of laser greatly improves the efficiency, as well as to facilitate the preservation and extraction of information, "laser revolution" is of extraordinary significance. Laser spatial control and time control is very good, the processing object material, shape, size and processing environment of the degree of freedom are very large, especially suitable for automated processing, laser processing system and computer numerical control technology can be combined to form a high-efficiency automated machining equipment, has become the enterprise to implement the production of the key technology, for high-quality, high-efficiency and low-cost machining and production opens up a wide range of prospects. At present, laser technology has been integrated into our daily life, in the years to come, the laser will bring us more miracles.
Laser is a modern new light source, with good directionality, high brightness, monochromatic and other characteristics and is widely used, such as laser distance measurement, laser drilling and cutting, seismic monitoring, laser surgery, laser vocoder and so on. The unique ablation effect, surge effect and radiation effect produced by laser weapons have been widely used in air defense, anti-tank, bomber and so on, and has shown its magical power. China's laser industry, there are two leaders, the south has a large laser, the north has a G Kodak (600986), it is interesting that the two laser shares of the liquidity of only 54.68 million shares and 49.53 million shares, respectively, is a pocket-sized, but the G Kodak's share price is less than a fraction of a large laser, after the market has a very strong potential for outbreaks. G Kodak's main business is the laser electronics, the company's cooperation with foreign capital, the production of internationally advanced The main business is laser electronic products, the company cooperates with foreign capital, the production of international advanced technology level of the laser head and related electronic products, the company installs and operates 24 production lines, the production of three types of machine types more than one model of the laser head products, can be processed annually a variety of laser head 48 million pieces, to become our country's largest production base of the laser head, and the line of the "Daqi Laser" dichotomy. G Kedar controlling subsidiary of the Dongying Koying laser Ltd., its business scope for the production and sale of electronic laser head, movement and related products, the leading product digital decoding laser head is widely used in computers, video disc players, game consoles and other high-tech electronic products, the current main customers are LG Electronics, Asus Computer, Jianxing Electronics and other famous IT manufacturers, due to the laser head and its series of products cohesion of optics, electronics, precision machinery, micro-computers, new materials, microfabrication and other high-tech essence, it is the most advanced technology, is the most advanced technology, is the most advanced technology, is the most advanced technology. As the laser head and its series of products are condensed optics, electronics, precision machinery, microcomputers, new materials, microfabrication and other high-tech essence of the crystallization of today's most advanced technology, the application prospects are very broad, the company's laser industry is expected to grow rapidly in the future.
In addition, G Kodak's parent company, Kodak Industry in G Kodak 05 annual report commitment, "Qingdao LPG low-temperature atmospheric pressure storage and transportation project" will be injected into the listed company after completion, so that G Kodak holding the largest liquefied petroleum gas base in East China project to create a huge profit growth, because liquefied petroleum gas is a seller's market, and the price is also a huge profit growth. Is a seller's market, and the price of liquefied petroleum gas may also surge, the company's development prospects are first-class. G Kedar and Daqi Laser is China's two giants of laser electronics, is the formation of the laser and liquefied petroleum gas construction projects two fist industry, especially liquefied petroleum gas project after the injection of the company's performance will skyrocket, and the current liquidity of less than 50 million shares, the price of shares in the vicinity of NAV, away from the 8.6 yuan Issue price, has a good value of investment speculation, the recent main force at the bottom of the intervention, the market is expected to dust, it is worth paying close attention to. Laser science is a new discipline developed in the 1960s, is one of the major scientific and technological achievements following atomic energy, computers and semiconductor technology.
Laser speed
Laser speed is the object to be measured twice with a specific time interval laser ranging,
To obtain the time period in the object to be measured within the moving distance, so as to get the object to be measured moving speed.
Therefore, laser speed measurement has the following characteristics:
1, because the laser beam is basically a ray, the estimated speed distance relative to the radar speed effective distance far, can be measured outside 1000M;
2, speed accuracy, error <1 kilometer;
3, in view of the principle of laser speed measurement, the laser beam must aim at the perpendicular to the plane of the laser beam reflection point, and the laser speed is the same as the laser beam, and the laser beam is the same as the laser beam, and the laser beam is the same as the laser beam. Plane reflection point of the beam, and due to the measured vehicle is too far away, and in a mobile state, or the car body plane is not large, which leads to low success rate of laser speed measurement, difficult, especially on-duty police officers work intensity, very easy to fatigue.
4, in view of the principle of laser speed measurement, laser speed detector can not have the use of the movement, only in a stationary state application; therefore, the laser speed detector can not be called "mobile electronic police". When used in a stationary state, the driver can easily find a detection, and therefore can not achieve the desired purpose.
5, expensive, now through the regular way to import the laser speedometer (excluding the view and control part) price of at least 10,000 U.S. dollars or so.