Zhang Wei-Li

Observation of High-Order Femtosecond Solitons in a Self-Mode-Locked Ti:Sapphire Laser

The N = 3 femtosecond solitonlike pulses are observed directly in a self-mode-locked Ti:sapphire laser as well as even higher-order solitonlike pulses for the first time. When the laser is operating in a stable train of mode-locked pulses, the periodic pulse train appears by only varying the intracavity dispersion. The soliton period with N = 3 corresponds to a cavity round trip number of 164.

Development of high performance polarizer coatings

The research and achievements of high performance polarizer coatings by many scholars around the world are reviewed, including the spectral properties, laser damage threshold and stress control. For the performance requirements of polarizer coatings in China Shenguang series facilities, it describes the investigation of spectral properties, laser damage threshold, and figure accuracy of the polarizer coatings based on electron beam depolarization by Shanghai Institute of Opitcs and Fine Mechanics of the Chinese Academy of Sciences(SIOM). Much work and achievements on design, preparation and past-treatment of the coating are given. On the basis of the research achievements, high performance thin films polarizer with low defect density and low stress have obtained. The Brewster angle thin film polarizer developed by our team has participated in the International Laser Damage Competition held on the SPIE 2012 Laser Damage & SPIE 2013 Laser Damage Symposium. The p-polarized LIDT(Laser Induced Damage Threshold) as well as the average of p-polarized and s-polarized LIDT achieves the best results. The stress-induced crazing of large aperture polarizer coating is also solved, by which the manufacturing of large aperture polarizer is implemented in China, showing the spectral properties of TP>98%, RS>99% and the flux property of 17 J/cm2(9 ns). Now, the prepared large aperture polarizer has supported the stable operation of ShenguangII-UP laser facility. ? 2016, Science Press. All right reserved.

Characterization of optical and microstructure properties of ultraviolet Sc2O3thin films and their damage mechanism at high laser power

The electron beam evaporation deposition method was employed to prepare scandium oxide(Sc2O3) films with substrate temperatures varying from 50 to 350 ℃. A spectrophotometer, a glancing incidence X-ray diffraction spectrometer and a WYKO optical profilograph were employed to investigate the optical, microstructure properties and surface roughness of the Sc2O3 films. The refractive index and the extinction coefficient were calculated from the transmittance and reflectance spectra with the help of the Essential Macleod. The laser induced damage threshold(LIDT) of the Sc2O3 films was characterized by a pulsed Nd:YAG laser system at 355 nm with a pulse duration of 8 ns. A maximum value of 2.6 J/cm2 was derived, and t