DYE-LASER PUMPED, CONTINUOUS-WAVE KTP OPTICAL PARAMETRIC OSCILLATORS

We report on dye-laser-pumped, continuous-wave (CW) KTiOPO4 (KTP) opti cal parametric oscillators (OPOs) with pump and idler resonant cavitie s. With a linear two-mirror cavity the pump power at threshold was 70 mW. The single-frequency signal and idler output wavelengths were tune d in the range of 1025 to 1040 nm and 1250 to 1380 nm by tuning the dy e laser in the range of 565 to 588 nm. With a dual three-mirror cavity the threshold was 135 mW. Pumped by 500 mW of 578 nm radiation the 10 40 nm single-frequency signal wave output power was 84 mW. Power and f requency stable operation with a spectral bandwidth of less than 9 MHz was obtained by piezo-electrically locking the length of the pump res onant cavity to the dye laser wavelength. Similar performance was achi eved by placing the idler resonant OPO inside the resonator of the dye laser. With this system power stable and single-frequency operation w as achieved with a spectral bandwidth of less than 11 MHz for the idle r wave.