OPO CARS - COHERENT ANTI-STOKES-RAMAN SPECTROSCOPY USING TUNABLE OPTICAL PARAMETRIC OSCILLATORS INJECTION-SEEDED BY EXTERNAL-CAVITY DIODE-LASERS

Coherent anti-Stokes Raman spectroscopy (CARS) is performed on nitroge n gas using the signal wave from a pulsed beta-barium berate optical p arametric oscillator (OPO), which has a passive ring cavity and is inj ection-seeded at its idler wavelength by a single-mode, external-cavit y diode laser. The observed CARS linewidths are consistent with an opt ical bandwidth of 0.01 cm(-1) for the continuously tunable OPO signal radiation. Moreover, injection seeding with two diode lasers generates two-line rovibrational CARS spectra giving thermometric information o n a single-shot basis. The utility of these OPO CARS methods for combu stion diagnostics is indicated.