Sequential Excitation Preparation of Molecular Energy Levels with Special Structural and Chemical Properties.

Abstract

Abstract : This report pertains to: (a) Stimulated Emission Pumping Studies of Formaldehyde. The Stimulated Emission Pumping (SEP) technique was applied for the first time to a polyatomic molecule, H2CO. SEP spectroscopy has provided an unprecedentedly complete picture of the structure of H2CO at high levels of excitation. (b) The H2CO S sub O yields H2+CO Barrier. Stark Quantum Beat and Anticrossing Spectroscopy were used to measure the homogeneous width of two S sub 0 rotation-vibration levels near the top of the S sub 0 barrier. (c) Collisional Studies of H2CO A 1A sub 1 Level. Two pulsed-cw variants of SEP, Transient Gain and Transient Gain and Transient Polarization Spectroscopy enable measurement of single-J level collisional depopulation and depolarization rates and state-of-state transfer rates free of the multiple-collision effects and limited resolution of resolved fluorescence studies. (d) Spectroscopic Studies of Na2. Two new techniques were demonstrated. Modulated gain spectroscopy has allowed observation of the levels of Na2 states near the Na (2S level)+Na(2P level) dissociation limit. Perturbation facilitated Optical-Optical Double Resonance has made the Na2 triplet valence and Rydberg states accessible to sub-Doppler spectroscopy. Originator furnished keywords include: Spectroscopy, Vibrational structure, Optical-optical double resonance, Molecular dynamics, Anharmonic vibrational constants, Electric dipole moment, Coriolis perturbations, Quantum chaos, Anticrossing and Quantum Beat spectroscopy, Barrier to Dissociation, Rotational energy transfer, and Formaldehyde.