使用聚焦的800nm,120fs,1kHz的超短脉冲激光在掺Ag^+的BK7玻璃内部空间选择性地写入了光栅结构,然后将样品在不同温度下进行热处理.吸收光谱表明,BK7玻璃在飞秒激光照射后产生了氧空位色心,在575℃热处理后析出了银纳米颗粒.光栅的衍射效率随热处理温度的升高而减小,在575℃后又开始升高.用光学显微镜观察了光栅的结构变化并对现象产生的机制进行了分析.
A grating structure was inscribed in a Ag^+-doped BK7 glass sample by a focused femtosecond laser (800nm,120fs and lkHz), and the glass sample was then annealed at different temperatures. Absorption spectra show that oxygen deficient centers are formed after the femtosecond laser irradiation and Ag nanoparticles are precipitated after annealing at 575℃. The diffraction efficiency of the inscribed grating decreases with further increase in annealing temperature above 575℃.The microstructure of the grating was also observed by an optical microscope and the mechanism of the observed phenomena was discussed.