title: High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity.
abstract: 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.
authors.affiliation: JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Boulder, Colorado 80309-0440, USA. rjjones@jilau1.colorado.edu
authors.forename: R Jason
authors.initials: RJ
authors.lastname: Jones
authors.forename: Jun
authors.initials: J
authors.lastname: Ye