MICROWAVE-OPTICAL-DOUBLE-RESONANCE STUDY AND OPTICAL RE-ANALYSIS OF CaF $A^{2}\Pi_{r}-X^{2}\Sigma$ BAND

Abstract

The excitation spectrum of $A^{2}\Pi - X^{2}\Sigma$ band system of CaF has been measured using tunable cw dye laser excitation spectroscopy. In order to obtain the precise rotational and spin-rotation coupling constants, the Microwave Optical Double Resonance (MODR) method has been applied to low J transitions. The MODR signals were observed as 1 to 2% increases in the optical fluorescence. The hyperfine splittings of the ground state could not be resolved because of the broad nature of the MODR lines. Using these precise ground state constants, we have reanalyzed the excitation spectrum of $A^{2}\Pi_{r} - X^{2}\Sigma$ system to obtain accurate constants for both states.