A CW DYE LASER FOR MICROWAVE OPTICAL DOUBLE RESONANCE SPECTROSCOPY

Abstract

A CW dye laser has been constructed which is sufficiently tunable, stable, monochromatic and powerful to observe microwave-optical double resonance in the $X^{1}\Sigma$ and $A^{1}\Sigma$ states of BaO. Similar double resonance experiments using the 496.5 nm line of an $Ar^{+}$ laser have been $reported.^{1,2}$ The laser is frequency stabilized and fine tuned with two internal etalons and operates in a single longitudinal mode with power near 50 milliwatts. A procedure has been developed to tune the laser to the wavelength of any molecular absorption line in the 565-620 nm spectral region. With occasional adjustment the laser will neither drift nor jump off of the desired molecular line.