ALL-SOLID-STATE MIDINFRARED FEMTOSECOND OPTICAL PARAMETRIC OSCILLATORBASED 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 1 06 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 effici encies 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 a utocorrelations at signal and idler wavelengths of 1.0 and 4.88 mu m, implying pulse durations of 210 and 190 fs, respectively, have been ob tained. (C) 1998 Elsevier Science B.V.