As a young subject, laser technology has brought about great changes in human science and technology, production and life. Whether in processing, scientific research, biology, cutting-edge technology and other fields, has a very large application space, and therefore sustained by domestic and foreign enterprises and research institutions attention, technology development. Since 2016, laser technology has also made a series of major breakthroughs, the following inventory ten annual burning laser pointer technology progress.
Photon impact heating of nanoparticles was observed for the first time
Lucas Nowotny of ETH Zurich, Switzerland, led the research team, for the first time measured the photon and micro particles collision when the micro "shock" warming effect. The team used laser to limit the radius of about 50nm silica nanoparticles in the optical trap, the optical trap environment is a super vacuum chamber. The researchers used a method called feedback cooling process, which capture the particle's position is monitored, and the trap frequency accordingly modulation, pulling away particle energy and reduce the temperature of the particle to the micro level of Kelvin. In ambient pressure greater than 10e9, the minimum temperature of the particle temperature is determined by pressure. Under 10e9, no matter how much pressure, the minimum temperature does not change with pressure. This means that, at very low pressures, the dominant limiting cooling factor is the electromagnetic noise in the trap.
Next, the team shut down the feedback cooling process at very low pressures, allowing trapped photons to freely heat their particles. The gap between the energy states of the oscillating particles is larger than the magnitude of each individual photon collision recoil energy, so the simplest photon scattering energy does not affect the elastic particles. Sometimes, however, photons excite nanoparticles into a higher state of oscillation, which gradually heats up. This warming is random, but, by repeatedly, their average results, researchers succeeded in warming the smooth curves show that when trapped in a high power laser pointer particle, faster heating rate.
Physicists break records of laser electron interactions
The researchers succeeded in converting the energy of an electron beam into a coherent optical pulse with a conversion efficiency of 30%, much higher than the efficiency of most free electron lasers (). In the demonstration test, they use a five meter long tunnel accelerated electron beam accelerator, a few meters long spiral path using magnets to guide the direction, to accelerate the electron at the same time, with the electronic infrared laser irradiation. In the laser irradiation makes the electronic speed at the same time emit infrared laser beam and the laser of the same wavelength, emitted by effective light amplification by stimulated emission of radiation in the process of amplification depends on the initial energy of electron beam. The team notes that it breaks the "free space propagation of laser pulses and a relativistic electron beam" interaction record. This method may help to achieve efficient, high-power lasers over a range of wavelengths, including X rays. Such X ray sources can be used for faster and more efficient etching circuits on semiconductor chips.
Ultra fast laser pulse power up to 6 femtosecond 200W world record
In order to develop the new high repetition rate ultrashort pulse laser, by researchers from Germany, Imperial University, Fraunhof schler Applied Optics and Precision Engineering Research Institute and Active Fiber Systems and other organizations to join the European Union ELI (Extreme Light Infrastructure) project to build a laser system can provide up to 6 FS 200W, refresh the world record. The laser system is based on a femtosecond fiber laser with two nonlinear compression stages. The pump source of the system includes an optical fiber chirped pulse amplification (FCPA) system with coherent combining system consisting of up to 8 main amplifier channels. In the first test, the system runs on 1.27MHz, providing 660W power. Final specifications will be set at 100 kHz and 100W. Through two nonlinear compression stages, the first phase provides approximately 30 fs pulses through the 408W power (equivalent to a pulse energy of about 320 J). After second stages and subsequent compression, 208W and 6.3 femtosecond ultrafast laser pointer pulses are finally realized.
Optical material coupling strength innovation record
In order to obtain the strong coupling of optical materials, Dr. IQC, Finn led the research team will wear this aluminum circuit dilution refrigerant, construct a cooling to degrees above absolute zero, up to one percent degrees Celsius in the superconducting circuit. The laser pulse is used to send photons into the superconducting circuit, and a small magnetic field is applied to control the quantum state in the circuit.
By measuring the photon transmission, the researchers identified the qubit resonance. Finn - Dai explained that they measured the resonance frequency range wider than the qubit itself frequency. This means there is a very strong interaction between photons and qubits. The experiment has created the strongest new record of light matter coupling, more than 10 times as strong as before. The researchers say that the latest research is making the study of the interaction of light matter into a new field, into the field of quantum optics. The circuit of the test has potential as a quantum simulator for studying other interesting quantum systems in nature. The strong quantum coupling between light and qubits helps scientists to further explore the physics of biological processes, high-temperature superconductors and other exotic materials and even relativity.
Shanghai Institute of Optics and laser generated Antimatter
Has antimatter ever existed? What is the form of existence? Has been the focus of scientists, which is one of the basic problems of modern physics research. Shanghai Institute of strong field laser physics national laboratory using femtosecond petawatt laser device and high pressure gas target interaction, resulting in a large number of high-energy electrons, the interaction of high-energy electrons and heavy nuclear material target, generating a high intensity gamma ray by bremsstrahlung mechanism, gamma ray and heavy nuclear effects produce electron positron pairs. The positron spectrometer is carefully designed to successfully solve the problem of noise caused by gamma rays, using different deflection characteristics of electron positron in the magnetic field, the experiment in the single condition successfully observed positron. This discovery will be of great importance in nondestructive detection of materials, green laser pointer driven Electron Positron Collider, cancer diagnosis and other fields.
Black phosphorus quantum dots preparation and application of ultrafast photonics field made new progress
Since 2014, black phosphorus has been widely concerned by the scientific community because of its excellent performance. It is considered as a two-dimensional atomic material comparable to Shi Moxi. However, according to the research of optical and ultrafast photonics on black phosphorus quantum dots has not yet been carried out. China Yu Xuefeng Academy of Sciences, Shenzhen Institute of advanced technology research group of Shenzhen University researcher and Professor Zhang Han research group, has made new progress in black phosphorus quantum dots preparation and ultrafast photonics applications. Black phosphorus quantum dots with a transverse size of about 2 nm were successfully prepared from black phosphorus materials by solvothermal method. This method not only can obtain uniform size black phosphorus quantum dots, but also can realize large-scale preparation. In addition, the research group also reveals that the black phosphorus quantum dots have more excellent saturable absorption characteristics than the black phosphorus nanosheets, the modulation depth is as high as 30% or so, and the saturation intensity is in the order of GW / cm2. The black phosphorus quantum dots as a saturable absorber in a mode-locked laser, ultrashort pulse can be generated in the communication band. The research results show that black phosphorus quantum dots quantum effect due to the restriction of its own, it has great potential in application of ultrafast photonics, is expected to become a new type of optical functional materials.
Bending laser beam transmitting information distance to create world record
The laser beam bending is different from the ordinary electromagnetic wave, different light it has different phase, a spiral in the road, the spiral curved beam encryption and transmission of information has almost no capacity constraints, communication is especially suited for satellite communication. University of Vienna scientists encrypted bending laser beam, so that the bending laser beam mileage reached 143 km. The record set a new world record, almost 50 times higher than previous records. This new breakthrough or to revolutionize the way satellite communications. In general, the atmosphere amidst the winds of change will cause interference to the transmission of information, resulting in transmission distance can not meet the actual application requirements. The new study created curved laser transmission information the most distant record, but the current encoding and decoding information is not faster than the Moss code used to send telegrams. R & D team will then use the existing adaptive optics and other technologies to improve the bending light system information transmission and compile speed.
Lasers and anti lasers occur simultaneously in the same device
Department of energy's Laurence Berkeley National Laboratory (Berkeley Lab) scientists first created a single device can simultaneously play the role of anti laser and 10mw laser pointer, this is a use of advanced nano processing technology for manufacturing 824 of the gain and loss of repeat material to form the device, as long as 200 micron devices the width of 1.5 microns. As a comparison, the diameter of a human hair is about 100 microns. The scientists demonstrated these two opposite functions in the telecommunications spectrum. These findings lay the foundation for the development of a new class of integrated devices that can be flexibly used as lasers, amplifiers, modulators and detectors. Schematic shows the input light (green) into the opposite ends of a single device. When the input optical phase 1 faster than the input light phase 2 (left), the gain medium is dominant, so as to obtain coherent amplification of incident light, or lasing mode. When the phase of the input light 1 slower than the input light 2 (right), medium loss dominates, resulting in coherent absorption of incident light, or anti lasing mode.
Cooling of superfluid using laser beam for the first time
Researchers at the University of Australia, Queensland, for the first time use laser beams to cool special forms of quantum liquids called superfluid. Lasers are widely used in cooling gases and solids, but have never been heard before for quantum liquid cooling. The results were published in the Journal Nature Physics. This study can be used to strengthen the guidance system sensor to develop quantum devices, fundamental research in quantum physics turbulence, or quantum fluid vortex when the temperature is close to absolute zero.
Scientists first successfully photographed 9 femtosecond laser intramolecular decomposition process
Scientists at the Kansas State University and the Barcelona Institute of science and Technology (BIST) in Spain, for the first time successfully captured the chemical reaction process of 9 atoms with a molecule of 4 atoms in a femtosecond laser. The latest research will provide powerful tools for scientists to observe different types of processes and molecular changes in chemistry, biology and physics. This is done by electron diffraction infrared laser induced a (LIED) technology, the use of electronic molecular internal molecular pictures obtained in acetylene chemical bond breaking process of continuous image. They applied a strong 100mw laser pointer to the acetylene molecule, activated an electron inside the molecule to leave, initiated the decomposition of the acetylene molecule, and finally took out multiple pictures of the molecular change occurring within 9 FS. This is the first time in real time to observe the molecular decomposition process within 9 fs. By means of femtosecond laser tools, the fracture position and order of chemical bonds can be measured to better understand and control the chemical reaction process.
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