基于声光偏频法的激光频率无调制锁定  

Modulation-free Frequency Locking of a Laser Based on Acousto-optic Frequency-shifting Method

作　　者：李志全[1] 陈曦[1] 朱国芳[1] 高天野[1] 闫聚兵[1] 刘世元[1] 

机构地区：[1]燕山大学电气工程学院,河北秦皇岛066004

出　　处：《光电工程》2010年第1期110-114,共5页Opto-Electronic Engineering

基　　金：国家自然基金资助(60877047);河北自然基金资助(F2008000873);教育部高等学校博士学科点专项科研基金资助(20070216004)

摘　　要：为了进一步提高1.5μm波段激光器的频率稳定性,利用声光调制器(AOM)的频移特性使激光发生频移,将乙炔(12C2H2)的υ1+υ3带的P9支吸收峰作为参考频率,通过两条频移的吸收谱线产生类色散鉴频曲线,实现对外腔半导体激光器的无调制频率锁定。实验中把以前直接对激光器的调制转移到声光调制器上,避免了直接调制所引入的额外噪声,通过闭环锁定,50s内典型的频率起伏达到5.8MHz以内,激光器的频率起伏较自由运转时明显得到抑制,实现了激光频率的稳定。In order to improve the frequency stability of laser in 1.5μm regions,two acousto-optic modulators were used to shift the laser frequency and the absorption spectra of an acetylene transition （12C2H2 P9） at 1530.37nm was used as the frequency reference. Then,the dispersion-like frequency discriminating curve was obtained by subtracting the two shifted absorption spectra of acetylene. The new method could avoid the extra frequency noise due to indirect frequency modulation of laser source in a conventional scheme. After locking laser,the typical frequency jitter was less than 5.8MHz in 50s,which is significantly better than the frequency fluctuation under free-running condition. Hence,the frequency stabilization of external cavity diode laser with a modulation-free output can be realized.

关 键 词：激光技术 外腔半导体激光器 分子吸收线 声光频移 无调制锁频 

分 类 号：TN248[电子电信—物理电子学]