基于纵模拍频控制的激光稳频技术

Laser Frequency Stabilization Based on Control of Intermode Beat Note

介绍了一种新的双纵模激光稳频技术:基于激光频率与纵模频率间隔的对应关系,通过精密锁相控制技术将两相邻纵模的拍频频率锁定在射频频率标准上,以控制激光谐振腔腔长,实现锁定激光频率的目的.理论分析表明,激光频率稳定度与两相邻纵模拍频频率的稳定度相同;实验上以射频频率标准为参考,精密锁定了He-Ne激光两相邻纵模的拍频频率及激光频率,且对采用该技术稳频的两套He-Ne激光系统进行了比对.实验结果表明,激光频率的稳定度为5×10-10(1 s积分时间),5×10-11(100 s积分时间).

A new frequency-stabilized two-mode laser was introduced. Based on the relationship between optical frequency and intermode beat note, the intermode beat note was locked to the radio frequency standard by precise phase-locking technique to keep the cavity stable, so laser frequency stabilization was realized. Theoretical analysis shows that the stability of the laser frequency is identical with that of the intermode beat note. Experimentally, the intermode beat note of He-Ne laser was precisely locked to the radio frequency standard, and the laser frequency was also locked. The frequencies of two frequency-stabilized HeiNe lasers were compared. The result showed that the laser had a frequency stability of 5×10 l0 at 1 s of averaging time and 5×10 n in 100 s of averaging time.