TY - JOUR AU - R. Jones AU - Jun Ye AB - 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 BT - Optics Letters DA - 2004-12 DO - 10.1364/OL.29.002812 N2 - 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 PY - 2004 EP - 2812 T2 - Optics Letters TI - High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity VL - 29 SN - 0146-9592 ER -