Automatic system to relock a laser frequency to a Fabry-Perot cavity

Seung Koo Lee, Byoung Woong Han, D. Cho

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


We developed a system that allowed us to unlock and at a later time automatically relock a laser frequency to a medium-finesse Fabry-Perot cavity. The system can work as a chopping wheel or a shutter for a laser field built inside a cavity. The heart of our system is the flywheel circuit for the slower-acting servo loop and the automatic gain control circuit for the faster-acting servo loop. The flywheel circuit stores a correction for a slow frequency drift so that during the unlocked period the slow loop can be safely turned off. The automatic gain control lowers the fast loop gain during a relock process and increases the gain after the lock is secured. The system works reliably at a chopping frequency up to 70 Hz, and relocks well after being unlocked for up to 10 s.

Original languageEnglish
Article number026101
Pages (from-to)026101-1-026101-2
JournalReview of Scientific Instruments
Issue number2
Publication statusPublished - 2005 Jan 25

ASJC Scopus subject areas

  • Instrumentation


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