记录飞秒级超快瞬态过程的脉冲数字全息技术

介绍了采用脉冲数字全息技术对空气电离中等离子体形成和传播过程进行全息纪录和数字再现的最新成果。由于在获取子脉冲串的过程中采用了创新的空间角分复用设计方案,实现了物波视角不变和具有飞秒时间分辨的多幅动态强度和相位图像。

基于“神光-Ⅱ”装置的飞秒拍瓦级光学参量啁啾脉冲放大的特性分析与系统设计

用计算机仿真分析了光学参量啁啾脉冲放大 (OPCPA)的特性及其影响因素 (如相位失配、高阶非线性效应等 ) .就脉冲放大机理、时间同步、光谱漂移、增益窄化等相似问题与现有的啁啾脉冲放大技术做了比较与讨论 .基于“神光 Ⅱ”装置 ,设计了飞秒拍瓦级OPCPA系统 ,以期望实现快点火 .

Pulsed digital micro-holography of femto-second order by double-wavelength recording

Double-wavelength recording used in a pulsed digital micro-holographic system to record ultra-fast processing of the order of femto-second is reported for the first time, where a BBO crystal is used to generate harmonic wave of the incident laser wave, and both of the basic and the frequency doubled waves are time-delayed and introduced to a Michelson＇s interferometer to record two sub-holograms with different spatial frequencies on a single frame of a CCD. In the experiment, an ultrafast dynamic process of air ionization induced by a single femto-second laser pulse is recorded with holography by this system, and both of intensity and phase difference images digitally reconstructed are obtained through Fourier transformation and digital faltering, which show clearly the dynamic process of formation and propagation of the plasma, with a time resolution of the order of femto-second.

超短脉冲激光加工陶瓷基复合材料制孔研究

陶瓷基复合材料由于能够提高零件的耐高温和推重比等性能,适用于航天发动机热端部件,但由于在传统加工过程中易出现崩边、层间撕裂等缺陷,且无法实现微孔加工限制了其使用。通过选择飞秒级超短脉冲激光加工制备陶瓷基复合材料微孔,探索加工方案、优化工艺参数,对加工后的表面完整性进行评价,确定了超短脉冲激光微孔加工孔径范围、几何精度及表面质量,有助于解决陶瓷基复合材料微孔加工难题。