Diode-pumped optical parametric oscillators

We report on diode-laser-pumped, continuous-wave-(CW) optical parametric oscillators (OPO). The results describe the operation and characterization of doubly and triply resonant CW-OPOs (DRO, TRO) based on the non-linear materials KTiOPO4 (KTP) and RbTiOAsO4 (RTA) and different cavity designs. Stable single-frequency operation with a maximum signal output power of 84 mW was obtained with a pump- and idler-resonant two-mirror RTA-DRO, by electronically locking the OPO's pump cavity to the diode master-oscillator power-amplifier (MOPA) pump source: We present signal wave RF intensity noise spectra of an RTA-TRO, which is pumped with an amplitude-squeezed diode laser. The OPO noise spectra demonstrate, for the first time, the presence of relaxation oscillations in CW-OPOs.