We demonstrate a general technique for enhancement of femtosecond pulses from a pulse train through their coherent buildup inside a high-finesse cavity. Periodic extraction of the intracavity pulse by means of a fast switch provides a net energy gain of 42 to >70 times for 38–58-fs pulse durations. Starting with an actively stabilized but otherwise standard mode-locked laser system, we demonstrate pulses of >200-nJ energy.
© 2004 Optical Society of America
(140.4480) Lasers and laser optics : Optical amplifiers
(320.0320) Ultrafast optics : Ultrafast optics
(320.7080) Ultrafast optics : Ultrafast devices
(320.7160) Ultrafast optics : Ultrafast technology
R. Jason Jones and Jun Ye, "High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity," Opt. Lett. 29, 2812-2814 (2004)