Photocathode Laser Oscillator with S-band Rf Oscillator*

We present the femtosecond synchronization between an 800-nm photocathode laser and an S-band RF oscillator using an optical-RF phase detection system at KAERI-WCI Accelerator. A 79.33-MHz commercial Ti:sapphire photocathode laser oscillator is locked to a 2.856-GHz RF master oscillator (RMO) using a fiberloop-based optical-microwave phase detector (FLOMPD), which results in 13 fs (rms) out-of-loop residual timing jitter integrated from 1 Hz to 10 MHz offset frequency. We also measured the long-term out-of-loop timing drift between the 800-nm optical pulse train and the RF signal, which results in 28 fs (rms) integrated over 1 hour.