光敏玻璃在飞秒激光作用下的析晶

采用高温熔融法制备了银掺杂的锂铝硅酸盐微晶玻璃.经近红外飞秒激光照射和热处理后,通过显微镜观察及X射线衍射分析发现,玻璃内部形成以银原子为晶核的Li2O·Al2O3·3SiO2多晶结构微晶,晶体细小,呈乳白色,为六方晶系,呈现空间取向分布结构.飞秒激光照射部位玻璃折射率发生明显变化,出现析晶;未照射部位折射率无明显变化,仍为玻璃体.利用光致折射率变化和飞秒激光的空间选择特性,可望在玻璃内部实现微光栅、波导、微机械器件、光学掩模等微结构.

Crystallization in PTR glass induced by irradiation of femtosecond lasers

Lithium silicate photosensitive glass doped silver is fabricated by means of high temperature melt in silica crucible. After irradiation of Ti-sapphire femtosecond laser followed by a thermo development which is photo-thermo-refractive(PTR)process,Li2O · Al2O3 · 3SiO2 micro crystalline phase structure is observed and confirmed in the glass matrix with the help of optical microscope and X-ray diffraction. The above micro crystal is white and hexagonal structure. Variation of the refractive index in exposed parts of glass happens while almost no apparent variation occurrs in unexposed parts. So this is a process of structure change with spatial selectivity. Based on photo-indued refractive index change of glass and spatial selectivity of femtosecond lasers,it is expected that micro grating,optical waveguide,MEMS devices,optical mask,etc,can be fabricated in the glass matrix.