Coherent antiStokes Raman spectroscopy (CARD) is performed in nitrogen gas (N 2) using the tunable signal wave from a pulsed optical parametric oscillator (OPO) based on beta-barium borate (BBO). The continuously tunable output frequencies and optical bandwidth of this PPO are controlled by injection seeding at the idler wavelength with single-mode radiation from an external-cavity diode laser (ECDL). Allowing for Doppler and pressure broadening, observed CARS linewidths are consistent with an earlier finding that the effective (scanned) spectroscopic bandwidth of radiation from the ECDL-seeded BBO OPO is approx.300 MHz. Novel two-color OPO CARS measurements that rely on the ability of a free-running OPO to be injection-seeded at two independent optical frequencies are also reported.
|Number of pages
|Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
|Published - 1996