Self-phase-locked degenerate femtosecond optical parametric oscillator.
We demonstrated a stable degenerate synchronously pumped femtosecond optical parametric oscillator (SPOPO) as a divide-by-2 subharmonic generator. The SPOPO exhibited passive all-optical self-phase-locking between the pump and signal/idler and thus required no external electronic feedback to produce the phase-locked subharmonic. We employed a type I phase-matched, 1-mm-long, periodically poled MgO:LiNbO3 crystal as the nonlinear gain element and an 80 MHz mode-locked Ti:sapphire laser with 180 fs pulses tuned at 775 nm as the pump. The SPOPO generated transform-limited 70 fs phase-locked output pulses centered at 1550 nm. The self-phase-locking operation was confirmed by separate beat-note measurement techniques with respect to the pump laser and with respect to an external cw laser.
Wong
Samuel T
ST
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA. stwong@stanford.edu
Plettner
Tomas
T
Vodopyanov
Konstantin L
KL
Urbanek
Karel
K
Digonnet
Michel
M
Byer
Robert L
RL