外延单片式激光二极管抽运被动调Q微激光器

Laser Diode-Pumped Passively Q-Switched Monolithic Microchip Laser Based on Liquid Phase Epitaxy

基于液相外延工艺,实现了一种结构新颖的单片式被动调Q微片激光器。采用了在激光介质Nd3+∶YAG表面直接液相外延生长一层具有饱和吸收特性的Cr4+∶YAG膜的微谐振腔的结构,由于是同质外延生长过程,能够确保饱和吸收体与增益介质间(Nd3+∶YAG/Cr4+∶YAG)良好的界面特性。采用光纤耦合激光二极管,在激光二极管输出为1W的抽运条件下,实现了峰值功率近千瓦、稳定重复频率在4kHz以上、脉宽1.8ns、TEM00单横模式、波长1.064μm的调Q脉冲序列输出。在对新型单片式微激光器的性能报道的基础上,阐述了外延单片式结构及其相应工艺的潜在优势。

A novel monolithic passively Q-switched microchip laser is presented with a microcavity by directly growing a thin Cr^4＋ ;YAG film with saturable absorption on the surface of the laser medium Nd^3＋ ： YAG by liquid phase epitaxy. Because of the homogeneous epitaxial process, a good interface property is achieved between active medium Nd^3＋ ;YAG and saturable absorber Cr^4＋;YAG. Pumped by 1 W output of a fiber-coupled laser diode, the novel laser produces Q-switched pulses sequence with wavelength 1. 064μm, pulse duration 1.8 ns, pulse repetition over 4 kHz, TEM00 mode and peak power nearly 1 kW. Except for the detailed descriptions of the performance of the laser, the potential advantages of the structure and relevant processes are also discussed.