The award-winning representative and the awarding guests took a photo. Image Source: China Laser
The deputy director of the selection committee, researcher Zhou Changhe of the Shanghai Guangji Research Institute, announced that the selection committee had announced the list of papers selected for the 2017 China Optical Top Ten Progression. Academician Fan Yanyuan, Director of the Selection Committee, and Academician Li Ruxin, Director of the Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences presented the awards to the representatives. And certificate. Prof. Huang Dongdong, Director of the Department of Electronics, Tsinghua University spoke as the winner.
Prof. Huang Xiaodong made a speech.
The two results selected by Tsinghua University are:
Prof. Liu Fangdong, Professor of the Department of Electronics Huang Weidong of Tsinghua University, developed an on-chip integrated free-electron light source, and for the first time in the world realized the thresholdless Cherenkov radiation. This result subverts the form of the traditional free electron light source, and also makes flying research on the chip. The interaction between electrons and micro-nanostructures becomes possible.
Prof. Huang Xidong's research group began research on micro-nanostructured optoelectronic devices in 2004. He has accumulated international leading advantages in micro- and nanostructured photoelectron physics and manufacturing processes, and test technology. Prof. Liu Fang, Associate Professor of the Research Group led the Ph.D. student Xiao Long et al. In the study of Cherenkov radiation in artificial hyperbolic metamaterials, it was found that in the hyperbolic metamaterial, no matter how slow the electrons are, radiation can be generated, ie, the thresholdless Cherenkov radiation can be realized.
(a) On-chip Cherenkov radiation sources, (b) Electron micrographs: (left) On-chip planar electron emission sources, (in) Hyperbolic metamaterials, (right) Surface plasmon-periodic nanoslits.
In order to verify this major discovery, after more than two years of unremitting efforts, members of the research team have continuously overcome many bottlenecks in the fabrication and testing of nanostructures such as on-chip planar electron emission sources, hyperbolic metamaterials, and surface plasmon polariton slits. After electrons were emitted from a molybdenum tip with a radius of curvature of several tens of nanometers, a 40-nanometer straight-line flight of 200 micrometers was performed on the surface of the chip. Eventually, a non-threshold Cherenkov radiation was observed. The radiation wavelength is 500 to 900 nm, and the electron energy is only It is between 250 and 1400 electron volts, which is 2-3 orders of magnitude lower than the electron energy of hundreds of thousands of electron volts required for the same kind of experiments reported so far. The experiment yielded 200 nanowatts of radiant light output power, which was obtained with other nanostructures. Compared to Cerenkov radiation, the output power is more than 2 orders of magnitude higher.
Threshold Cherenkov radiation experimental results.
Tsinghua University's Department of Electronics Professor Ning Cunzhen's research group combined single-layered molybdenum diselenide with silicon-based nanoarm cavity and realized for the first time in the world a two-dimensional material nanometer laser operating at room temperature. This result is based on silicon-based lasers and excitons. Research on polarimetric lasers is of great significance.
The research group led by Prof. Ning Cunzheng from the Department of Electronics of Tsinghua University combined with the experience of nano-laser research carried out over the years, using a single layer of deuterated molybdenum with a thickness of only 0.7 nm as a gain material, with a width of only 300 nm and a thickness of more than 200 nm The silicon nanoarm cavity is used as a laser resonator. The research group found that in the above two-dimensional material, the binding energy of electrons and holes is very high, and a stable exciton state can be formed with high luminous efficiency. Silicon-based nanoarms The cavity has an ultra-high optical quality factor, and the exciton radiation wavelength of the molybdenum diseloxide has almost no absorption in the silicon material. Therefore, the combination of the “strong-strong” two-dimensional material and the silicon-based nanoarm cavity is to operate the laser. The important reason why the temperature is raised to room temperature.
Schematic diagram of nano lasers based on two-dimensional materials.
The reticular structure shows a single layer of two-dimensional material, and underneath is a silicon nanocantilever used as a laser cavity.
This research requires the fabrication of a nanometer cantilever structure with precise dimensions and etching of one-dimensional circular hole arrays of different sizes on the cantilever. At the same time, the single-layered two-dimensional material is accurately transferred to the nano-cantilever structure. Nano-technology has brought great challenges. Professor Ning Cun-zheng led young teachers Li Yongzhuo and others to overcome a series of difficulties and finally realized for the first time in the world that the two-dimensional material nano-laser operates at room temperature.
Schematic of optical amplification with nanowire waveguides (left), scanning electron micrographs of nanowires (right).
The research on nano-laser is of great significance for basic research and practical application. First of all, two-dimensional material as the thinnest optical gain material has been proved to support laser operation at low temperature, but whether this single-layered molecular material is sufficient to support room temperature The laser operation still has doubts in the scientific and technological community. Room temperature operation is the premise of the practical application of most lasers. Therefore, the room temperature operation of the new laser has an index significance in the history of semiconductor laser development. In addition, due to the strong Coulomb in the two-dimensional material Interactions, electrons and holes always appear in exciton states, so this laser is actually closely related to a new type of exciton polariton Bose-Einstein condensate, which is the most active in the field of basic physics One of the topics.
The other eight major optical research advances in basic research categories are: Chaotic Highway, a photon momentum conversion discovered by Peking University; All-optical drive developed by Shanghai Institute of Optics, Chinese Academy of Sciences, and a 'micro-wavelength' device that generates strong terahertz radiation. Nankai University uses a complementary light-absorbing strategy for oligomeric materials to construct a stacked organic solar cell device with broad spectral absorption characteristics; Sun Yat-sen University cooperates in designing a valley photonic crystal to obtain a new energy valley-strontium spin interaction and achieve Spin-spin and topology control; Southeast University realizes parity-time symmetrical quantum walk in open system, and observes new one-dimensional topology protection boundary state; Generalized magnetic mirror of National University of Defense Technology; Huazhong University of Science and Technology based on orbit resolution Atomic-scale molecular nuclear dynamics detection of high-order harmonic spectroscopy; Nanjing University found that three-dimensional Dirac semi-metal film material can be used as an ideal switch material for the preparation of high-performance mid-infrared pulsed lasers.
The research progress of the top 10 optics in the Applied Research category are: Peking University has developed a new generation of miniature two-photon fluorescence microscopy; Zhejiang University has for the first time achieved large-field-of-field marker-free far field nano-microscopic imaging on nano-illuminated tablets; National Nanoscience Center has been successfully developed. Molecular Spin Photovoltaic Device; X-ray Detector based on non-lead perovskite single crystal developed by Huazhong University of Science and Technology; Zhejiang University collaborates to achieve sub-wavelength all-optical simulation; Chinese Academy of Sciences Xinjiang physics and chemistry successfully developed a new generation of deep-ultraviolet nonlinear optical crystal material Shanghai Jiaotong University has successfully developed a silicon-based integrated wide-range continuously adjustable light buffer/delay chip; Suzhou Institute of Nano-technology and Nano-Bionics, Chinese Academy of Sciences realizes a refractive index sensor integrated with an ultra-material absorber structure and a microfluidic channel integration; Chinese Academy of Sciences The Institute of Chemistry proposed the concept and design method of hidden photonic barcodes based on organic whispering chamber microcavities; Beijing Jiaotong University has made new progress in the research of ultra-narrowband response-doped organic photodetectors.