构建了一种基于Littman-Metcalf结构的外腔半导体激光器。该激光器采用基于星形柔性铰链转动机制的紧凑型设计,并利用有限元分析的方法对其机械结构进行了分析及设计,转动臂实现了高达3.7kHz的基模共振频率。根据无跳模调谐条件对外腔设计进行了优化,提高了激光器的性能。该激光器为单纵模运转,工作波长约为780nm,无跳模调谐范围大于等于80GHz,且在无重新装调情况下可稳定工作一年以上,表明激光器具有良好的可靠性。同时该激光器可锁定在87^Rb(F=2→F’=2,3)吸收峰上,持续时间超过24h,其线宽为200kHz,温度稳定度为35MHz/℃,且稳频激光器的Allen方差在测量时间为3S时可达到3.5×10^-11,24h内光功率波动小于0.75%,具有较高的稳定性。
An external cavity diode laser (ECDL) with Littman-Metcalf configuration is constructed in this paper. The ECDL adopts a compact structure with a star-flexure hinge as the tuning mechanism. Its mechanical characteristics and design are analyzed and optimized by finite element calculations. The first order resonance frequency of tuning arm is measured as 3.7 kHz. The laser cavity structure parameters are designed according to the mode-hop-free tuning condition, and the performance of the ECDL is obviously improved, showing single-mode operation with mode-hopping free tuning range over 80 GHz at 780 nm. The device has been operating stably without realignment for more than one year, indicating its good ruggedness. The frequency of ECDL can be locked at 87^Rb(F=2→F'=2,3) transitions. The linewidth of 200 kHz and temperature stability of 35 MHz/℃ are measured, and the Allen deviation reaches 3.5 ×10^-11 in 3-s integration time. Its output power is continuously monitored with fluctuation below 0.75 % for 24 h, showing with good stability.