F-P腔不同扫频段透射谱锁频精度实验

Locked frequency accuracy experiment of transmission spectrum of F-P cavity under different sweep frequencies

针对窄线宽激光器输出谱线窄,难以被锁定的情况,利用F-P腔特有极窄线宽、高精细度特性对激光器谱线线宽实施压窄及频率锁定。通过设计实验方案并搭建锁频测试平台,利用F-P腔外部光反馈将窄线宽半导体激光器线宽压窄来提高锁频精度。通过监测正弦波调制下F-P腔对于4种不同直流电压下激光PZT扫频段的透射谱线,并对其分别进行解调和锁频精度测试,得到直流高压放大器电压为73V时对窄线宽激光器进行扫频,激光器反馈锁频精度最高可达1.5MHz。

Aiming at the problem that the output spectrum of narrow linewidth laser is narrow and difficult to be locked ,the Fabry-Perot(F-P) cavity which has the unique narrow linewidth and high-definition features was used to do linewidth narrowing and the frequency locking . Based on the advantages of F-P cavity ,the experiment plan was designed and a test platform was built ,the external cavity optical feedback technology was employed to improve the accura-cy of locked frequency .The transmission line was monitored under the sine wave modulation of F-P cavity with different laser piezoelectricity (PZT ) sweep frequencies at four direct current (DC) voltages ,then the demodulation was conducted and the locked frequency accuracy was tested .As a result ,when using 73 V DC high voltage amplifier to sweep the narrow linewidth laser ,the laser feedback locked frequency precision can be up to 1 .5 M Hz .