title: Dual-color operation of a femtosecond optical parametric oscillator exhibiting stable relative carrier-envelope phase-slip frequencies.
abstract: A femtosecond optical parametric oscillator is demonstrated that can operate in a regime where two signal pulses with well-separated center wavelengths are simultaneously resonant. Measurements show that the oscillator output contains a stable modulation at a frequency corresponding to the difference in the carrier-envelope phase-slip frequencies of the co-resonant pulses. The physical origin of this internal beat signal is attributed to second-order mixing effects, and its frequency is shown to be consistent with theory.
authors.affiliation: Ultrafast Optics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK. j.sun@hw.ac.uk
authors.forename: Jinghua
authors.initials: J
authors.lastname: Sun
authors.forename: Barry J S
authors.initials: BJ
authors.lastname: Gale
authors.forename: Derryck T
authors.initials: DT
authors.lastname: Reid