Laser is another serious creation of mankind since the 20th century, after atomic energy, accounting machine and semiconductor.
In 1960, Theodore Maiman of Hughes laboratory in California completed the first laser beam. Only a year later, lasers were first used in surgery to kill retinal tumors. In 1962, the semiconductor diode laser was created, which is the backbone of today's small commercial lasers. In 1965, the first equipment that can produce high-power laser -- carbon dioxide laser tube was born. In 1967, the first X-ray laser tube was successfully developed. In 1969, the laser was used for remote sensing survey. The laser was fired at the reflector placed on the surface of the moon by Apollo 11, and the measured Earth Moon distance error was within a few meters. In 1971, laser entered the art international for stage lighting effects and laser holography. British Hungarian physicist Dennis Gabor won the Nobel Prize for his research on holography.
C-band linear accelerating laser tube
In 1960, Meiman successfully developed the first practical ruby laser in the world
It can be seen that since the birth of laser, laser skills and the use of laser have been constantly developed, and the speed of development is amazing. So far, laser is still a hot topic in the field of research, and many research directions are derived from laser as the core. Not only that, but also as a kind of thing, laser has accelerated the progress of other high-precision fields.
Progress in research on film damage mechanism of Shangri
The output level of high power laser system is closely related to the laser damage resistance of thin film components. With the development of the coating process, the defects originated in the coating are largely suppressed. The defect originated from substrate plays an increasingly prominent role in the process of laser-induced damage of thin-film components, which has become a key factor limiting the improvement of damage threshold of thin-film components at the fundamental frequency of Nd: YAG laser.
With the help of femtosecond laser micromachining channel, the laboratory of Shanghai Institute of Optics and mechanics of China Academy of Sciences has made pits with specific size on quartz substrate (length: ~ 7um, width: ~ 3um, depth: ~ 1um). The laser-induced damage behaviors of antireflection coatings and high reflective coatings deposited on conventional substrates with femtosecond laser processing pits are studied and compared.
The results show that the defect of absorbing impurities plays an important role in the mechanism of laser induced damage. In the process of thin film preparation, the absorbing impurities on the surface of substrate move to the surface of substrate and aggregate larger scale impurity particles, which then couple with the film, and induce the antireflection membrane components to damage under the laser irradiation whose energy flow density is far lower than the intrinsic laser damage threshold of the film. The coupling between substrate defect and coating can be suppressed by corresponding skills (such as lowering the coating temperature, acid cleaning before coating, etc.), and then the anti laser damage ability of antireflection coating can be improved.
Dalian physicochemical Institute of physics and chemistry added heavyweight brothers to the world's largest crystal laser data
Recently, Liu Shengzhong, a member of the research group of silicon-based solar cells (dnl1606) of the National Laboratory of clean energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, led his team in the first time to prepare super large-scale single crystal perovskite ch3nh3pbi3 crystal with the size of more than 2 inches (more than 71 This is the first time that perovskite single crystals with a size of more than 0.5 inch have been reported in the world.
Because of its high optical absorption coefficient, long carrier transmission interval and few defect density of States, the perovskite PBH data have become excellent photovoltaic data, laser data and luminescence data.
C-band RF speeds up to 50mV / m free electron laser ushers in great progress
Shanghai Institute of Applied Physics of Chinese Academy of Sciences, together with the 12th Research Institute of China Electronics Technology Group (CL12) and Shanghai Sanhao Vacuum Technology Co., Ltd. (Sanhao vacuum), successfully developed the high gradient C-band RF acceleration skill unit through long-term theoretical research and skill tackling. The technical unit experiment and discussion were carried out in SDUV-FEL accelerator channel The experimental results show that the research on this skill has made great progress.
C-band RF acceleration technology is a new high gradient acceleration skill developed in the world. It is used in FEL and medical and industrial accelerator. In 2011, Japan built an 8gev C-band linear accelerator with a beam acceleration gradient of 35mV / M; Switzerland and Italy have also developed their own C-band acceleration structures, and are building C-band accelerators for FEL and Compton Backscatter light sources. According to the available literature, their high-power test acceleration gradient is up to 55mV / m, and the belt acceleration gradient is up to 55mV / m The maximum is 45mv / m. The breakthrough reached the international first.
The laser window of single nonlinear crystal will be larger
Since the emergence of laser, people have successfully expanded the laser window to deep ultraviolet, visible, infrared, terahertz and other scales by using various nonlinear optical effects (frequency doubling, sum frequency, difference frequency, etc.) in nonlinear optical crystal data, and completed broadband coherent light source and ultrafast pulse laser.
High order harmonic generation in chirped nonlinear photonic crystals
The research group used the mid infrared femtosecond laser to carry on the experiment