Investigation of laser-induced polarization spectroscopy of nitric oxide

Single-photon laser-induced polarization spectroscopy (PS) of spectroscopy of nitric oxide (NO) was performed using a high-resolution optical parametric oscillator (OPO)/optical parametric amplifier (OPA) system. The OPO/OPA system is injection-seeded using a near-infrared telecommunications diode laser and pumped using the third harmonic output of an injectionseeded, Q-switched Nd:YAG laser. The PS measurements were compared with single-photon laser induced fluorescence (LIF) measurements of NO. The effect of the variations in the electronic quenching rate on the PS and LIF signals was investgated by performing measurements in a jet flow of NO in a buffer gas of N2with different levels of O2added to the buffer gas. The PS signal was found to be much less sensitive to variations in the electronic quenching rate. Saturation of the LIF and PS processes with increasing laser power was also investigated. The measured PS spectra are compared with the results of a theoretical analysis. The time-dependent density matrix equations used to model the interaction of the high-resolution laser radiation with the molecular resonance are solved by direct numerical integration.

Investigation of laser-induced polarization spectroscopy of nitric oxide Conference Paper