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.