4B9 - High resolution spectroscopy by Zeeman-tuned infrared laser

We have designed a Zeeman-tuned laser oscillating at nearly all laser transitions between 3 and 9 μm, and we have studied absorption bands between 1250 and 1450 cm^-1where many xenon and neon laser lines have sufficient gain to allow displacements of 0.1 cm^-1The apparatus is an internal-mirror discharge, dc excited, on a granite bench well isolated from mechanical vibrations. The Fabry-Perot cavity is 1.66 meter. Applied axial magnetic fields vary from 0 to 1800 Gs. The circular polarizations are converted to linear perpendicular polarizations by a quarter-wave plate consisting of a Fresnel prism. The laser beam, after passage through the absorption cell, is detected by a Ge-Au cell behind a monochromator. The detected signal and the magnetic field are simultaneously recorded by an recorder.