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In the 1970s, a man named Gordon Moore predicted his performance in the semiconductor industry by doubling the chip's performance every 18 months. This prediction over the past 40 years all the way to prove his right, and the transistor density of the chip also followed by doubling, doubling, and then double. For people who are familiar with the chip, high-performance is usually associated with this high fever, with our dependence on electronic products increasing, mobile phones, laser 5000mw,flat panel, notebook computers and other heating problems, not only negative impact on the experience, The manufacturers to design a more beautiful, lightweight new products.

To solve the electronic products, especially micro-electronic devices of the heat, we must first understand the root causes of these heat generated. And the answer may be hidden in the latest paper published by Dr. Liao Linlin. The former Sichuan Province college entrance exam tutor from Professor Chen Gang, this year from the Massachusetts Institute of Technology received a doctorate. His research team accurately measured the interaction between electrons and phonons, the results not only explain the micro-electronic equipment, the causes of fever, but also can be used to further improve the performance of thermoelectric materials.

With the development of semiconductor chips, more and more transistors are stuffed into smaller and smaller spaces. Massachusetts Institute of Technology engineers recently found that mobile phones, laptops and other electronic devices will be hot, the main reason is that electronic and thermal energy to carry the phonon interaction. This interaction was once overlooked by scientists, but the latest research results show that in microelectronic devices, this interaction has a significant impact on heat dissipation, the related research results published in the October 12 of the "Nature Communication ".

In the 1970s, a man named Gordon Moore predicted his performance in the semiconductor industry by doubling the chip's performance every 18 months. This prediction over the past 40 years all the way to prove his right, and the transistor density of the chip also followed by doubling, doubling, and then double. For people who are familiar with the 3000mw laser pointer chip, high-performance is usually associated with this high fever, with our dependence on electronic products increasing, mobile phones, flat panel, notebook computers and other heating problems, not only negative impact on the experience, The manufacturers to design a more beautiful, lightweight new products.

Thermoelectric materials have a very wide range of applications, including thermal detectors and NASA's latest proposed for space exploration equipment, nuclear batteries. The phenomenon of electron scattering by phonons is not new, but has long been neglected by scientists. With the continuous development of semiconductor technology, the concentration of electrons becomes higher and higher, this phenomenon can not be ignored. Scientists must think about how to manipulate the electron-phonon interaction in order to increase the efficiency of the thermoelectric device on the one hand and prevent the microelectronic device from heating up on the other.

Phonon and electronic bumper car games

Whether in 20000mw laser transistors (semiconductor materials, such as silicon) or wire (conductor material, such as copper), the electronic current movement is the main medium. The reason why resistors exist is that the electrons flow through a roadblock - a phonon carrying thermal energy collides with electrons, pushing it out of the current path. For a long time, scientists have been investigating the effects of electron-phonon interactions, but the focus has been on electrons rather than on how the interactions affect phonons. "Scientists rarely study the effects of this interaction on phonons, because they think this effect is not important," Liao Lin said, "but Newton's third law tells us that each force has a reaction force, but we do not know what The reaction will become important. "

Scattering, heat is difficult to coexist

According to Liao and colleagues, when the electron concentration exceeds 1019 electrons per cubic centimeter, the interaction of electrons and phonons in silicon, the most commonly used material in semiconducting materials, can produce a large scattering of phonons. When the electron concentration reaches 1021 per cubic centimeter, the heat dissipation capacity of the material will be reduced by phonon scattering by 50%. "This is a very significant effect, but many people are doubtful," Liao Lin Lin said. This is mainly because in previous experiments with high concentrations of electronic materials, scientists have assumed that the cooling capacity of the decline is not due to electron - phonon interaction, but due to material defects caused. These defects are due to the doping of materials, silicon, for example, phosphorus and boron are commonly used doping atoms, the purpose is to increase the material's electron concentration. Therefore, to verify Liao Linlin's theory, it is necessary to separate the electron-phonon interaction and the influence of defects on heat dissipation capacity. The specific method of implementation is to increase the electron concentration in the material, but not to introduce any defects.

The team developed a technique called three-pulse photoacoustic spectroscopy to optically increase the concentration of electrons in silicon crystal thin films and measure phonon production in the material Of any impact. The technique is an extension of the traditional "two-pulse photoacoustic spectroscopy" in which the scientists accurately control the timing of the two blue laser pointer beams. The first beam produces phonon pulses in the material and the second beam measures the scattering or attenuation of the phonon pulses. Liao Linlin introduced a third laser beam, which can accurately increase the electron concentration in the silicon material without introducing any defects. After the third laser beam is emitted, the measurement results show that the phonon pulse decay time is significantly shortened, which indicates that the electron concentration increases the phonon scattering and inhibits its activity.

The experimental results show that the introduction of the third burning laser pointer can shorten the decay time of the phonon pulse. The larger the laser intensity (the higher the electron concentration), the shorter the decay time of the phonon pulse. The result was a great excitement for Liao Lin's team, which was a good match for their previous calculations. "We can now determine the effect is very obvious, and we confirmed it in the experiment," Liao Lin Lin said, "This is the first can directly detect the electron - phonon interaction on the impact of phonons experiment." Interestingly, The concentration of 1019 electrons per cubic centimeter, than some of the existing transistor is even lower, in other words, the latest discovery of this phenomenon is part of the existing microelectronics fever one of the culprits. "According to our research, this effect will become increasingly important as the size of the circuit gets smaller," says Liao. "We must seriously consider this effect and study how to use or avoid its effects."

In the past 10 years, the global laser system has maintained a 7% annual growth rate, which in 2015 laser materials processing system market reached 11.8 billion US dollars, industrial laser 3.2 billion 3.7 times. In 2005, China's burning laser pointer materials processing system only about 3 billion US dollars of turnover, accounting for only 5% of the global market. In 2011, the domestic market grew to $ 1.8 billion. In 2015, to $ 2.8 billion, accounting for 24% of the global market. Since the 1990s, the United States in the field of industrial manufacturing created a new application of laser systems; since then 20 years, Europe will replace the United States as the industry leader; in 2015, China replaced Europe, the first time to become the largest laser system, the consumer market .

Those who have been concerned about the development of the laser industry should be remembered that Japan was almost the world's largest laser market in the 1980s, but then the market share fell and industrial productivity shifted from Japan to other countries with low labor costs. Of course, we do not want China to happen in the future. At present, the domestic laser material processing market prosperity, established in the domestic large and growing industrial base. As long as China's manufacturing growth rate is higher than other parts of the world, is expected to laser materials processing system demand will be higher than the average growth rate.

Fiber lasers dominate

In 2005, fiber lasers accounted for 37% of the global 20000mw laser materials processing market share, in addition, gas lasers accounted for 37%, high-capacity solid, semiconductor lasers accounted for 26%. The market share of fiber lasers has increased significantly over the past 10 years, from 4 percent in 2005 to 14 percent in 2010, up from 37 percent in 2015, to $ 3.2 billion. Over the past five years, fiber laser processing market has been the average annual growth rate of nearly 30%. Fiber laser in the field of rapid development of materials processing, thanks to the following three aspects: First, the application in the marking, the replacement of solid-state lasers; Second, in metal cutting, replacing the CO2 laser; Low-power laser welding, fiber lasers occupy a large market share. At the same time, the industrial laser market is still a large part of fiber lasers can not be involved, including micro-processing applications, because the fiber laser can not provide the required specific wavelength pulse. There are some ablation and structural processes and micro-lithography processing, a lot of non-metallic materials processing technology, more favored in long-wavelength CO2 lasers.

Fiber lasers market share can continue to grow long

According to market assessment, fiber lasers in the alternative to other lasers on the road will continue to make strides. Now, fiber lasers have dominated the laser marking market, but also in sheet metal cutting and high-power welding, but also significantly better than CO2 lasers. In the high-power laser cutting and welding market, fiber lasers will increasingly compete with disk and diode lasers, not just CO2 lasers. However, it should be emphasized that fiber lasers not only replace the solid-state lasers in the laser marking market, but also promote the low cost of industrial applications of lasers. Fiber lasers for marking have been developed to a low cost of several thousand dollars. In metal cutting, because the fiber laser is low in price, easy assembly, greatly reduces the overall cost of the system.

The use of fiber lasers has only just been realized in the field of laser material manufacturing, and now only plays a small role in replacing other types of lasers. Pulse fiber 500mw laser in the pulse welding and drilling applications more and more successful, and ultra-fast fiber lasers also began to get involved in the field of micro-processing. In view of these market developments and opportunities, the demand for fiber lasers is expected to continue to grow with the growth of the market, but the long-term growth rate may be lower than in the past to a certain extent.

http://gofishtalk.com/profiles/blogs/unmanned-vehicles-enter-the-data-competition

http://laserman.bcz.com/2016/10/11/the-application-of-3d-laser-scanning-in-industry/

As we all know, laser cutting machine cutting sheet metal has an unparalleled advantage, not only cut high precision and smooth section without burr, whether it is cutting thick plate or sheet can achieve good results, however, these effects are with the laser cutting machine The focus of control is not off the relationship, just like SLR camera focus, to achieve better imaging results is a principle.

In the application of high power laser pointer cutting to get up early, the main way to focus is to rely on manual to complete, and now with the development of laser technology, this manual focusing method has gradually phased out, auto focus has slowly begun to achieve, Laser full range of laser cutting machines are equipped with fully automatic focus function. Well, some people will say that the optical path is integrated in the cutting head inside, by changing the height of the cutting head is not to achieve focus function? The cutting head is raised, the focus position is high, the cutting head is lowered, and the focus position is low.

Cutting head at the bottom of the nozzle, in the cutting process, the nozzle and the distance between the workpiece (nozzle height) of about 0.5 ~ 1.5mm, may wish to be seen as a fixed value, the nozzle height unchanged, it can not lift the cutting head to adjust Coke (otherwise can not complete the cutting process). The focal length of the focusing lens is unchangeable, and therefore can not be expected to focus by changing the focal length. If you change the position of the focus mirror, you can change the 300mw laser focus position: Focus lens down, the focus down, focus lens up, the focus increased. - This is indeed a way of focusing. Using a motor-driven focusing mirror for up and down movement, can achieve automatic focusing. Another method of autofocusing is to change the position of the focal point by changing the curvature of the reflecting mirror and changing the angle of divergence of the reflected beam before the beam enters the focusing mirror, by setting a variable curvature mirror (or tunable mirror).

With auto-focus function, in the processing of different materials, different thickness of the workpiece, the machine can automatically focus to quickly adjust to the most appropriate location. This can significantly improve the laser cutting machine processing efficiency, plate punching time will be substantially reduced. Therefore, the 50mw green laser cutting machine, the auto-focus function is an important and indispensable function.