Highly tunable, multi-GHz repetition rate optical parametric oscillator driven by an electro-optic comb

Ultrafast optical parametric oscillators (OPOs), providing tunable pico- or femto-second pulses in the near- and mid-inrared (mid-IR), have attracted massive attentions and been used in various applications. Traditionally, these OPOs are synchronously pumped by mode-locked lasers and thus have repetition rates typically at tens or hundreds of MHz level. Further increase of the OPO repetition rate to multi-GHz level can be achieved by increasing the pump repetition rate [1] , [2] , which usually involves challenging cavity design, insufficient output power as well as relatively long picosecond pulses. Alternatively, one can use a high harmonic OPO cavity [3] , which, however, will inevitably create an uneven envelope of the GHz pulse train due to round-trip loss in the cavity. Here, leveraging the recently emerging cavity-less GHz electro-optic (EO) frequency comb technique, we demonstrate a new kind of GHz-repetition-rate OPO synchronously pumped by an EO comb.