All-solid-state, mid-infrared, femtosecond optical parametric oscillator based on periodically-poled lithium niobate

We describe an all-solid-state collinearly-pumped femtosecond optical parametric oscillator based on periodically-poled lithium niobate and tunable in the infrared from 996 nm to 1.22 mu m (signal) and 2.6 to 4.98 mu m (idler). Maximum output powers of 240 mW for the signal and 106 mW for the idler are recorded with 25 mW of average power measured at 4.88 mu m. An overall conversion efficiency of 35% and slope efficiencies for the signal of 40% at a wavelength of 1.04 mu m and 70% at 1.1 mu m are measured. Using dispersion compensation, interferometric autocorrelations at signal and idler wavelengths of 1.0 and 4.88 mu m, implying pulse durations of 210 and 190 fs, respectively, have been obtained. (C) 1998 Elsevier Science B.V.