Laser communication more intuitive understanding is the use of laser transmission of information communication. Its technical principle and the principle of radio communication is similar, that is, the first sound signal modulated onto the red laser beam, and then send the laser with the sound signal.
The laser itself has the characteristics of high brightness, strong directivity, good monochromaticity and strong coherence. In addition to the language information language, the laser can transmit characters, data, images and other information.
The advantages of laser communications: large communications capacity, in theory, laser communications can simultaneously send 10 million television programs and 100 million road phone. Confidentiality, the laser is not only extremely strong direction, and can be used invisible light, which is not easily intercepted by the enemy, the confidentiality is good. The structure is light and the equipment is economical. Since the divergence angle of the green laser pointer beam is small and the directivity is good, both the transmitting antenna and the receiving antenna required for laser communication can be very small. Generally, the diameter of an antenna is several tens of centimeters and the weight is only a few kilos, microwave antenna, the weight of a few tons, more than ten tons of dollars.
Communications distances are limited to line-of-sight (kilometers to tens of kilometers) and are subject to the effects of the weather and even disrupt communications in harsh climates. Atmospheric oxygen, nitrogen, carbon dioxide, water vapor and other atmospheric molecules on the optical signal absorption; atmospheric molecular density and suspended in the atmosphere of dust, smoke, ice, salt particles, microorganisms and tiny water droplets and other optical signals Scattering effect. Clouds, rain, fog, snow and other laser so severely attenuated. Atmospheric turbulence caused by air convection on the Earth's surface can have effects such as beam deflection, beam spread, beam flare (random variation of bright and dark spots within beam cross-section), and image jitter (random jump of beam convergence point).
Different laser wavelengths have different reduction in the atmosphere in the house. Theory and practice show that the laser attenuation of the wavelength is 0.4 ~ 0.7 m, and the wavelength is 0.9, 1.06, 2.3, 3.8, 10.6 m, respectively. The laser with 0.6 m wavelength has stronger fog penetration ability. Atmospheric most powerful lasercommunication can be used for communication of rivers, lakes, border areas, islands, mountains, canyons and other places. It can also be used in microwave communication or coaxial cable communication, temporary repair equipment when interrupted repair. Blue green laser with wavelength of 0.5 m can be used for underwater communication or submarine communication.
Aiming difficult. The laser beam has a very high directivity, which brings with it many difficulties in aiming at the transmitting and receiving points. In order to ensure the aiming between transmitting and receiving points, not only the high stability and precision of the equipment are put forward, but also the operation is complicated.
The main application of laser communications: short-range communication between the ground; short distance transmission of fax and television; due to the large burning laser pointer communication capacity, for missile range data transmission and multi-channel communication between the ground. Global and satellite communications through satellite total reflection, and underwater submarine communications.
برچسب ها: laser pointer
[ بازدید : 44 ]
[ دوشنبه 15 آبان 1396 ] 13:14 ] [ Mike ]
According to the website of the Institute of Physics reported on July 31, 2017, the University of Rice researchers by changing the surface of the wood, so that the wood into an electrical conductor. Researchers use the laser to darken the film pattern and place it on the pine. This is a composite structure of wood and nanomaterials.
In 2014, Rice University researchers used burning laser pointer-heated polyimide sheet surface to develop a thin atomic carbon material called laser-induced graphene (LIG), a porous graphene film with a flexible surface. The film used in this technology is laser-induced graphene.
"In addition to polyimide, some wood can also produce laser-induced graphene." The study found that pine trees are more suitable than woods with low cross-linked lignocellulose content, says Professor James Thor, a professor of chemistry. Production of high quality graphene. Lignin is a composite organic polymer that forms a rigid cell wall. New technology for the preparation of laser-induced graphene has opened up new applications, such as for three-dimensional graphene printing, polyimide non-ideal substrates. In addition, the wood is also rich in reserves and renewable.
As with the use of polyimide to prepare 5mw laser pointer-induced graphene, the new technology requires the use of standard industrial lasers at room temperature and the use of inert argon or hydrogen. Because there is no oxygen, the heat generated by the laser will not ignite the pine, but will produce graphene foam corrugated sheet, and wood surface bonding. In addition, changing the laser power can also alter the chemical composition and thermal stability of the laser-induced graphene. When the laser power is 70%, the laser will produce the highest quality laser induced graphene, called "P-LIG".
Researchers have made a pair of electrocatalysts with high surface area by depositing cobalt, phosphorus, nickel and iron on laser-induced graphene, which is durable and effective to decompose water into hydrogen and oxygen. In addition, the deposition of polyaniline on green laser pointer-induced graphene can also be used as a capacitor to store energy.
There are many applications that need to be explored, for example, using laser-induced graphene integration with solar cells. We believe that this discovery will inspire scientists to think about how to develop natural materials around them into more efficient materials.
برچسب ها: laser
[ بازدید : 59 ]
[ سه شنبه 17 مرداد 1396 ] 16:36 ] [ Mike ]
Laser chiller products with cooling effect, the low cost of cooling the characteristics of the installation of the use of 10mw laser pointer chiller before the first requirements of the relevant staff familiar with the equipment performance, understanding the use of common sense, care equipment, serious operation. The following is the chiller manufacturer of laser chiller introduction.
for the protection of circulating water pump, no water running!
to ensure that the chiller into the wind, the air passage is smooth, do not put foreign matter into the equipment inside!
When an abnormality occurs, stop the machine operation, turn off the power, feedback to the professionals, and remember that it can not be used.
open the package, check the machine is intact, the annex is complete. The installer 5mw laser pointer must have relevant expertise
to confirm that the equipment is properly grounded, although the average operating current of the chiller is not large, but its instantaneous operating current is sometimes up to 6 ~ 10 amps
Unscrew the machine water inlet and add cooling water. Can only use neutral pure water, do not allow water containing granular solid.
When the water temperature is lower than the ambient temperature, and the ambient humidity is large, the circulating water pipe and the surface of the cooling device will produce condensate.
Characteristics and function of laser chiller
the refrigeration system are used international brand components, control accuracy of ± 0.3 ℃ ~ ± 0.5 ℃;
the circulating water system using industrial plastic rust pump, stainless steel water tank, PVC connection material, no rust worries;
compact design, installation, easy to operate;
with a flow protection 30mw laser pointer device, can output signals to external devices;
the thermostat using independent research and development production of electronic thermostat, a variety of settings and fault prompt function, just a key operation (open key), the other by the memory function automatically.
The working principle of the laser chiller is to inject a certain amount of water into the stainless steel tank of the chiller and cool the water through the cooling system of the chiller (the refrigeration compressor draws the low pressure and low temperature refrigerant gas in the evaporator into the cylinder, So that it becomes a gas with a high pressure and a temperature, enters the condenser, and the high-temperature and high-pressure refrigerant gas exchanges heat with the cooling medium cooling air, transfers heat to the laser chiller, and the refrigerant gas condenses into the high-pressure liquid )
And then by the chiller water pressure will be low-temperature cooling of the water to be cooled to the cooling of the 300mw laser pointer equipment, this time through the chiller frozen water will take away the heat in the laser machine after the temperature rise and then back to the tank and then Chiller cooling cooling cycle, to achieve the role of cooling.
برچسب ها: laser
[ بازدید : 140 ]
[ دوشنبه 12 تير 1396 ] 15:47 ] [ Mike ]
Fiber lasers have proven their core competitive advantage in the cutting field. The Yb-doped fiber laser with wavelength of 1070 nm is the ideal light source for laser cutting, excellent beam quality, high anti-material reflection, and high efficiency is the advantage of fiber 5mw green laser in cutting application. Looking back, we have shown that using long pulse cutting can achieve higher efficiency. QCW quasi-continuous laser is more compact than lamp pump Nd: YAG laser, and its low power, low cost, low heat input, high pulse energy, high brightness, high electro-optical conversion characteristics give it high quality cutting The advantages:
To meet the needs of low-power single-mode laser and high-power multi-mode laser cutting between the needs of the blank, can be a variety of thickness of the material cutting. QCW quasi-continuous fiber lasers, with excellent modulation and pulse waveform shaping (waveform editing) capabilities. Pulse modulation enables QCW to significantly improve machining quality and speed in applications such as cutting, welding, punching, surface cleaning, etc., for 10-100% modulation and climb for only 10 μs. Talking about QCW cutting non-metallic materials, you have to mention sapphire, ceramics and other brittle materials. The cutting of these materials, scribing and other applications are very sensitive to heat, the accuracy of a very high demand. The following advantages that QCW can bring to the cutting and scribing of these brittle materials are critical to stable scale production.
Laser manufacturing technology after years of research and development, covering the red laser pointer surface engineering, laser welding, laser cutting, laser hole, laser marking, laser material manufacturing as the representative of the macro-manufacturing technology to laser micro-welding, laser precision cutting, Laser-induced drilling, laser ablation, etc., and the preparation of femtosecond laser, two-photon polymerization, interference lithography, contact ion lens sequence, laser induced surface nanostructure and nano-particle laser preparation On behalf of the laser micro-nano manufacturing technology and other extensive research areas, across the millimeters, microns and nano-scale, become a pivotal advanced manufacturing core technology, will play an indispensable role in the future. Among the above research areas, ultra-fast laser micro-nano processing is undoubtedly the current and future period of research hot spots, the research prospects are very optimistic.
As the ultra-fast 100mw laser pointer in the energy density and the role of time and so can be extremely extreme, and make its manufacturing process using the physical and chemical effects, the mechanism of action is different from the traditional manufacturing, such as non-linear (multi-photon, etc.) And non-equilibrium between lattice, non-equilibrium between electrons, etc.) and non-thermal phase transition (Coulomb explosion, electrostatic ablation, etc.). Ultra-fast laser micro-nano manufacturing contains the cutting edge of the manufacturing base of hot spots, due to the extreme elements of manufacturing, ultra-fast laser manufacturing process of observation, analysis and understanding there are still many problems to be revealed, in particular, these special features of the manufacturing Principle applied to more areas, you must have a more profound grasp of its manufacturing mechanism and laws.
In the short term, micro-nano manufacturing technology will not have a significant impact on environmental and energy costs. Subject to the current processing technology constraints, these technologies in the early stages of development tend to have a higher energy costs. At the same time, micro-nano manufacturing once mature, will consume less 50mw green laser energy and resources, in this regard, micro-nano manufacturing is undoubtedly an exciting technology. For example, unlike the removal of a trim, the resulting laminate process will result in less waste.
Ultrafast laser nano-processing cutting-edge technology, ultra-fast laser technology, ultra-fast laser nano-processing typical industrial applications. The conference will invite domestic and foreign laser technology research, laser devices and equipment research and development, laser processing applications related enterprises, research institutes and universities, research institutes, laser micro-nano processing applications of well-known leaders, around the theme of the conference, Ultrafast 1mw laser pointer and micro-nano processing technology in the field of cutting-edge technology and hot issues, the latest technology developments related to the field, to promote ultra-fast laser micro-nano processing technology development and application.
برچسب ها: laser
[ بازدید : 96 ]
[ دوشنبه 14 فروردين 1396 ] 16:16 ] [ Mike ]
Google originally is used in laser radar industry leading manufacturers Velodyne top products HDL64E, using 64 line laser specifications, superior performance. The principle of its application to receive the reflected 300mw laser pointer emission, depicts the space around the 3D form, high precision, and can detect subtle movements within 100 meters of mankind. However, behind the high-end performance is expensive prices, the price of up to $75000. In addition to other devices, Google each test car is simply the price of automatic driving. Google said in the 2012 summit, the unmanned vehicle, the automatic driving vehicle installed a $150 thousand additional equipment -- the price is 2 times more than the Lexus RX450h car test. High cost of hardware has become a huge drag, so that Google unbearable. According to foreign media reports, Google began hiring engineers at the end of the year before, to conduct research and development of laser radar. A year later, this has not been the news team finally got the results, come up with far and near are responsible for the detection of two laser radar, and its cost is reduced by 90%.
According to the news of domestic auto companies, laser radar is expensive, a big reason is actually a monopoly. In the automotive industry, the solution provided by radar and camera, although the price is low, but the effect is always not as good as high-end laser radar. In order to ensure the safety and accuracy, most manufacturers often use the best 400mw laser pointer radar. The most cutting-edge 64 line laser radar only Velodyne a company can produce, which makes it a dominant market in the high-end laser radar, the lack of competition, so that the downstream manufacturers no bargaining room. So the truth is, although the high cost of laser radar, Velodyne more by virtue of its monopoly position, rely on the "price black box", from the downstream firms earn high profits.
So Waymo will reduce the cost of laser radar, should not sell for $75 thousand as a benchmark, but should be compared to the manufacturing cost price HDL64E, but it relates to commercial secrets, can make this type of laser radar, only this one, the information transparency is low, the amount is difficult to accurately estimate.
The complex structure of a large part of the mechanical laser radar high cost comes from it, the precision optical element is very much, and in the automatic driving demand also needs a plurality of (8, 16, 32, 64 etc) laser emission lines, increase the number of lines has greatly increased the difficulty of installation and debugging. Even more deadly is that there is no ability to deal with such a task of automated production machinery, all mechanical 500mw laser pointer radar are skilled manual installation and debugging step by step. Therefore, the production of laser radar needs to spend a lot of manpower, but also low productivity poor. Labor costs are high, it is difficult to large-scale, automated production, so that the high price of mechanical laser radar. Solid state laser radar will transmit, receive, deal with the original are done on a chip, can be directly and mature microelectronics industry, large-scale, automated production.
Previous speculation that there are two main types of Google automatic driving the industry's business model: one is their own cars, equipped with automatic driving system of their own, similar to Tesla; two is the underlying supplier of automatic driving system, give up autonomous cars at Google, people have to think that this is Google in the future in the field of automatic driving role. However, in the current situation of many competitors, only a set of automatic driving software, the downstream customers - car manufacturers, it is obviously not enough to see. So Google out of the third way: the integration of hardware and software solutions provider.
After Google in the autopilot hardware does not have much contribution, although the realization of independent production of other sensors, but they are not better than good, but the key depends on the 1000mw laser pointer radar in Velodyne. Waymo is now carrying the automatic driving system of laser radar and two core technology solutions, integrated hardware and software have the ability to provide first level, for many are eager to accelerate their self driving process of the automobile manufacturers, this is a can not ignore the potential partners.
In the Waymo announced that its cost is reduced by 90% after laser radar, computer vision star company Mobileye shares fell 4.4%, the latter mainly rely on the camera to provide automatic driving solutions, is the largest supplier in the field. There are some common radar and camera and 2000mw laser pointer radar for competition, they are in a weak performance, previously with cost advantage, has become the current mainstream hardware automatic driving system, once the cost is no longer dominant, the living space will be seriously squeezed. Even if the lidar can not work in certain weather conditions, the camera and the ordinary radar as an important assistant can not give up, but for the Mobileye, it will be in the industry's position is not as good as before.
برچسب ها: technology
[ بازدید : 181 ]
[ پنجشنبه 5 اسفند 1395 ] 14:03 ] [ Mike ]
High-power, high-brightness fiber Gatling laser pointer make rapid laser scanning (RLS) applications rapid development. Compared to other technologies, RLS has greater flexibility and faster processing speed, and greatly reduce the large-size workpiece processing cycle. So, how does the fiber laser use its performance advantages in remote laser scanning applications? (Beam parameter product [BPP] <1.5 mm-mrad)? Due to the special optical performance, high-brightness fiber lasers can enable system integrators to achieve remote processing, effectively improve the remote processing head in the operation of the security. And through the rapid positioning of the beam with the scanning head combination, En resistance has been successfully achieved on the aluminum, copper and other high thermal conductivity metals, as well as new, lightweight carbon fiber composite materials, remote laser cutting, etching and welding.
Conventional fiber lasers use fiber-coupled technology to couple multiple 3000mw green laser outputs together, resulting in lower brightness of the output laser. The new generation of fiber lasers uses an innovative architecture that combines the pump diodes and drivers into separate pump modules. The gain fiber is mounted in a configurable gain module that can output more than 8kW of laser power. The gain module is based on the novel main oscillator / power amplifier (MOPA) design, enabling high-brightness laser output. In addition, the Ennie laser also uses a reliable integrated backlash isolator to protect all modules from the impact of backlit light, can be high anti-material for full power, uninterrupted, stable processing. These two technological innovations play a vital role in RLS applications.
High-brightness fiber green astronomy laser processing of high thermal conductivity material, it is best to use a small spot to maintain the stability of the welding hole, but this process may make the process is too intense, resulting in a large number of welding splash. Experiments show that high-brightness laser with high-speed positioning of the remote scanning head, significantly reduce the welding splash, which is achieved by beam swing to ensure that the welding hole stability to achieve. Figure 3 shows that welding copper, aluminum, if you do not use the beam swing mode, welding splash will be very serious. Once the high-frequency swing beam is used, the splash will be reduced. In addition, En-resistant laser's original anti-high anti-technology in this application is also indispensable, by installing a protective device to avoid the equipment by the back light damage. Processing of copper and aluminum such high reflective metal, the backlit light is inevitable, the traditional laser due to the natural sensitivity of the return light, may lead to processing instability and destructive automatic shutdown, or even scrapped.
Another application with high-speed scanning of fiber high power laser pointer with significant advantages is the cutting, 3D shaping and drilling of carbon fiber composite materials (CFRP). Carbon fiber composites, also known as carbon fiber laminates, are widely used in automotive lightweighting and are a new generation of more energy efficient and safe manufacturing materials. Carbon fiber composite material is a high-purity carbon fiber braid and hardened composite materials (such as epoxy resin) bonding, very strong and hard.
Today, in the field of transport, especially in the aircraft and automotive industries, there are lightweight needs, which reduce energy consumption and CO2 emissions and other sustainable development strategies have far-reaching significance. Large-scale manufacturing markets (such as cars) are increasingly demanding fast and low-cost manufacturing processes, including carbon fiber composite molding, joining and cutting processes. The mechanical cutting of long fiber composites will cause the machine tool to be worn and must be replaced by frequent burning laser pointer cutting tools to maintain the accuracy of the parts, increasing the processing cycle and manufacturing costs. In addition, machining usually requires water to cool the parts and remove debris and reduce dust. After cutting, in order to reduce the impact of water on the components, often have to dry the parts, extending the entire manufacturing process. Another challenge for water jet cutting is the need for complex water pipelines. Laser technology for the processing of carbon fiber composite material provides no wear, no external and anhydrous processing technology, and fast, high degree of automation, easy to solve the carbon fiber composite mechanical cutting all the shortcomings.
A new generation of fiber lasers is revolutionizing kilowatt-class materials processing. This combination of high-speed scanning system performance, can be achieved before the processing speed and application speed. Anti-high anti-technology to achieve high-reflective material full power, uninterrupted welding, while ensuring continuous and stable weld quality. The combination of high-brightness 2000mw green laser and scanning systems for the cutting and etching of carbon fiber composites enables high-speed, high-quality machining and minimal thermal impact, and has contributed to the development of advanced new materials processing technologies.
برچسب ها: technology
[ بازدید : 99 ]
[ پنجشنبه 28 بهمن 1395 ] 14:52 ] [ Mike ]
Laser precision machining in fine-tuning of functions such as thin-film circuits, fine tuning of piezoelectric quartz resonators and single-layer filters, modification of photomasks, fine tuning of ultra-high frequency circuits with distributed parameters, engraving of optical disks and reticles System and other industrial fields will be more and more widely used.
In the mobile terminal, digital cameras, portable and other mobile equipment production sites, the use of precision burning laser pointer trimming machine as a processing technology equipment, there is a high-precision laser cutting machine, laser cutting machine, laser cutting machine, Great potential for development. Resistance to high technical content requirements, need to master the laser focus and image monitoring technology. Coaxial CNC and automatic image recognition and positioning technology, ATE (automated test tooling) technology.
The laser resistance trimming is performed by short pulse laser scanning to cut the conductive cross-sectional area of the resistor and to adjust the resistor body lower than the target resistance value to the tolerable tolerance range. A 500mw laser pointer beam is irradiated on the resistive film according to a certain locus, and the resistive paste layer of the substrate is heated and vaporized by laser irradiation to form a certain depth, thereby changing the conductor cross-sectional area and the conductor length of the resistor body so as to achieve fine- the goal of. At the same time, the resistance of the dynamic measurement, the measurement results and set the resistance to compare, and feedback control of laser fire movement, to meet the requirements.
The existing mode of operation is the use of precision resistance artificial measurement adjustment, this approach requires more labor, or use the potentiometer for resistance adjustment, but the existence of overshoot, the potentiometer will rebound, resulting in circuit oscillation, the Move or transport process is also easy to loose, resulting in parameter drift. And many of the resistance of the circuit resistance requirements are very accurate, the relative error requirements of a few thousandths or even a few brightest laser pointer thousandths, and thick-film screen printing operation due to the inherent inaccuracy of the substrate surface and the sintering conditions are not uniform Repeatability, thick film resistance is often positive and negative error, the manufacturing process relative error can only reach 5%, or even lower, so the resistance must be fine-tuned to achieve high precision requirements.
Advanced 5000mw laser pointer trimming system uses a large number of LSI, VLSI circuit, with most of the software operation instead of many hardware functions. The core is directly connected to the laser, beam positioning, step-repeat and measurement systems via hardware. The measurement system consists of a passive network using a combination of precision bridges and matrices.
At present, in the country, precision laser trimming machine in addition to three precision can be independent research and development, can produce and sell the equipment manufacturers few. Cutting the resistive substrate by a short pulse laser scanning to make the resisting paste layer vaporized by high power laser pointer heating to form a certain depth of the nick, thereby changing the conductive cross-sectional area and the conductive length of the resistor body to achieve a resistance lower than the target resistance The body is transferred to the allowable deviation of resistance range.
Laser trimming machine, easy to control accuracy, speed, and easy to automate and mass production, and to complete the function of the circuit resistance, is currently the mainstream of the resistance process.
برچسب ها: technology
[ بازدید : 94 ]
[ سه شنبه 26 بهمن 1395 ] 16:23 ] [ Mike ]