|Remote two-color optical-to-optical synchronization between two passively mode-locked lasers|
|Full Author List||L.-J. Chen, H. P. H. Cheng, J. E. May, S. Smith, K. Muehlig, A. Uttamadoss, J. C. Frisch, A. R. Fry, F. X. Kärtner, and P. H. Bu|
Using balanced detection in both the radio frequency (RF) and the optical domain, we remotely synchronize the repetition rate of a Ti:sapphire oscillator to an Er-doped fiber oscillator through a 360 m length-stabilized dispersion compensated fiber link. The drift between these two optical oscillators is 3.3 fs root mean square (rms) over 24 hours. The 68 MHz Er-doped fiber oscillator is locked to a 476 MHz local RF reference clock, and serves as a master clock to distribute 10 fs-level timing signals through stabilized fiber links. This steady remote two-color optical-to-optical synchronization is an important step toward an integrated femtosecond fiber timing distribution system for free-electron lasers (FELs); it does not require x-ray pulses, and it makes sub-10-fs optical/x-ray pump-probe experiments feasible.