A new method for testing aspheric surfaces by annular subaperture stitching interferometry is introduced. It can test large-aperture and large-relative-aperture aspheric surfaces at high resolution, low cost, and high efficiency without auxiliary null opt
利用CO2激光辅助等离子体激励式化学气相沉积系统(Laser-assistedPlasma-enhanced Chemical Vapor Deposition,or LAPECVD),在硅(Si)基片上沉积出非晶形含氢较低的氮化硅(a:Si-Nx:H)薄膜。这些薄膜的折射率增加、膜致密性及平整度良好,其抗腐蚀性亦明显提升。LAPECVD沉积法是在电容式RF放电解离反应气体的同时,以输出功率密度3.3W/cm2的CO2激光斜向照射在硅基片上。因为激光斜照在硅基片上所提升的温度只有55℃,且可大量减少膜中的
We systematically investigate the influences of the input infrared spectrum, chirp, and polarization on the emitted intense terahertz spectrum and spatial dispersion in lithium niobate via optical rectification. The terahertz yield and emission spectrum d