Dual-wavelength synchronously-pumped femtosecond optical parametric oscillator using antiresonant ring interferometer

This work reports on a novel technique for coupling two resonant optical cavities using an anti-resonant ring (ARR) interferometer. The ARR is a well-known optical element and has been suggested for applications in lasers and optical parametric oscillators (OPOs). In this new application, the ARR acts as a two-port connector providing an intracavity common path for the two resonant signal fields, while avoiding inter-coupling between the gain media. As a result, two resonating wavelengths can be tuned independently and arbitrarily. In this paper, two femtosecond OPOs based on identical 0.5mm-long MgO:PPLN crystals with fanned gratings are synchronously-pumped at 800 nm by a KLM Ti:sapphire laser.