高稳定度窄线宽激光器的研究

Narrow linewidth lasers with high stability

介绍了3种不同类型的高稳定度窄线宽激光器的研究进展。基于Littman结构和饱和吸收光谱稳频技术,研制了稳频外腔半导体激光器系统,输出波长为780.2nm,频率稳定度1MHz,不失锁时间大于12h。利用边带稳频技术将分布反馈(DFB)激光器的输出波长稳定在Cs原子的吸收谱线的边带处,引入数字信号处理器(DSP)全数字稳频控制技术,实现了自动找频和稳频,获得波长为852.3nm的稳频激光输出,24h内频率漂移为±2MHz。利用国产磷酸盐玻璃光纤作为增益介质,实现了一台高功率单纵模光纤激光器,制作的厘米级激光器实现了最大输出功率100mW,利用外部光反馈实现单偏振运转,测得输出线宽为2kHz,偏振消光比优于35dB。

Three types of narrow linewidth lasers with high stability were introduced. A frequency stabilized external cavity diode laser was constructed based on Littman structure and saturated absorption spectrum freqency stabilized technique. The output wavelength was 780.2 rim. The frequency fluctuation was below 1 MHz in short term, and the phenomena of losing lock were not observed in 12 h. A frequency stabilized distributed feedback diode laser at 852.32 nm was constructed by locking its frequency to the side of the molecular absorption lines of Cesium. Fully automatic lock in the selected transition was realized with a digital signal processor （DSP）. The maximum frequency variation was ±2 MHz in 24 h. By regulating external feedback, single frequency and single polarization fiber laser was realized using a domestic Er：Yb co-doped phosphate fiber as gain medium. Up to 100 mW output power was achieved. The polarization extinction ratio （PER） was superior to 35 dB and the linewidth was near 2 kHz.