采用偏振光谱对外腔半导体激光器稳频时反馈环路带宽的影响  

Influence of the Bandwidth of Feedback Loop in Frequency Stabilization of External-Cavity Diode Laser by Polarization Spectroscopy

作　　者：王婧[1] 杨保东[1] 何军[1] 赵江艳[1] 张天才[1] 王军民(指导)[1] 

机构地区：[1]量子光学与光量子器件国家重点实验室,山西大学光电研究所,山西太原030006

出　　处：《光学学报》2009年第2期425-430,共6页Acta Optica Sinica

基　　金：国家自然科学基金项目(60578018,10434080,60821004);教育部新世纪优秀人才支持计划(NCET-07-0524);国家重大研究计划课题(2006CB921102);高等学校博士点专项(20070108003);山西省自然科学基金项目(2007011003);山西省回国留学人员基金资助课题

摘　　要：在采用磁光阱实现单个铯原子俘获的实验中,运用无调制偏振光谱方法将光栅外腔半导体激光器(提供冷却/俘获光)的频率锁定在铯原子6S_(//2)F=4→6P_(3/2)F′=5的超精细跃迁线上。采用偏振光潜技术得到的类色散曲线作为鉴频信号,并同时对光栅外腔半导体激光器的电流调制端口和光栅外腔的压电陶瓷电压调制端口进行反馈,以拓展反馈环路的带宽,实现激光器的频率锁定。与通常的饱和吸收光谱稳频技术相比,激光频率锁定之后的频率稳定度得到了明显改善。在取样时间τ=300 s时,阿仑方差σ_y(τ)=4.6×10^(-12)。Based on the experiment of trapping single cesium atoms in magneto-optical trap （MOT）, a grating- external-cavity diode laser, which provides the cooling/trapping beams of MOT is locked to cesium 6S1/2F = 4→ 6P3/2F＇ = 5 cycling transition by modulation-free polarization spectroscopy. This frequency locking method uses the dispersion-like curve generated from polarization spectroscopy as frequency-discriminating signal. The error signal is feedback to both current modulation port of diode laser and voltage modulation port of piezoelectric transducer （PZT） in grating external cavity. The locking technique of modulation-free polarization spectroscopy can clearly improve the frequency stability compared with conventional saturation absorption spectroscopic technique. The minimum value of Allan variance is σy（τ） = 4.6 × 10^ 12 at average time of τ = 300 s.

关 键 词：外腔半导体激光器 偏振光谱 稳频 反馈环路带宽 单原子磁光阱 

分 类 号：TN248.4[电子电信—物理电子学] TN249