飞秒激光诱导Li_2O-Nb_2O_5-SiO_2玻璃析晶拉曼谱研究

Raman study of crystals precipitation in Li_2O-Nb_2O_5-SiO_2 glass induced by infrared femtosecond laser pulses

通过使用波长800nm、重复频率250kHz的飞秒激光脉冲聚焦进Li_2O-Nb_2O_5-SiO_2组分的玻璃内部,在玻璃内容空间选择性诱导出铌酸锂微晶.为了进一步地研究辐照区域晶体的生长机制,使用显微拉曼光谱仪分析了玻璃样品辐照区域不同位置的结构变化.研究表明,在飞秒激光辐照一段时间后的聚焦区域,由于非线性效应和热累积效应形成了一个高温辐射梯度场,在激光辐照中心区域超过玻璃的析晶温度而促使玻璃熔融析晶.

This paper reports the precipitation of microcrystallites inside Li2O-Nb2O5-SiO2 glass by using 150 fs, 800 nm, 250 kHz femtosecond laser pulses. In order to study the growth mechanism of the induced crystal around the laser irradiated region, a micro-Raman spectroscopy was employed to analyze the structural changes of glass sample at different positions. The Raman results reveal that a kind of crystal structure as similar as LiNbO3 is generated in the focused region after femtosecond laser irradiation. The heat accumulation effect and nonlinear effect result in the glass melting and promote thermal crystallization.