Author: Kim, J.
Paper Title Page
WEPSO33 Remote RF Synchronization With Femtosecond Drift at PAL 570
 
  • J. Kim, K. Jung, J. Lim
    KAIST, Daejeon, Republic of Korea
  • L. Chen
    Idesta Quantum Electronics, New Jersey, USA
  • S. Hunziker
    PSI, Villigen PSI, Switzerland
  • F.X. Kaertner
    CFEL, Hamburg, Germany
  • H.-S. Kang, C.-K. Min
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Funding: This research was supported by the PAL-XFEL Project, South Korea.
We present our recent progress in remote RF synchronization using an optical way at PAL. A 79.33-MHz, low-jitter fiber laser is used as an optical master oscillator (OMO), which is locked to the 2.856-GHz RF master oscillator (RMO) using a balanced optical-microwave phase detector (BOM-PD). The locked optical pulse train is then transferred via a timing-stabilized 610-m long optical fiber link. The output is locked to the 2.856 GHz voltage controlled oscillator (VCO) using the second BOM-PD, which results in remote synchronization between the RMO and the VCO. We measured the long-term phase drift between the input optical pulse train and the remote RF signals using an out-of-loop BOM-PD, which results in 2.7 fs (rms) drift maintained over 7 hours. We are currently working to measure the phase drift between the two RF signals and reduce the phase drift over longer measurement time.