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 : 54 ]
[ 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 : 66 ]
[ 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 : 168 ]
[ 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 : 102 ]
[ دوشنبه 14 فروردين 1396 ] 16:16 ] [ Mike ]