Ultrahigh-resolution spectroscopy and frequency standards in the microwave and far-infrared regions using optical lasers

Optically induced resonance Raman transitions in atomic and molecular beams are proposed as a means of achieving ultrahigh resolution in the microwave and far-infrared regions. Line broadening that is due to laser jitter is eliminated by correlating the frequency jitter of the two optical fields inducing the Raman transition. A Ramanseparated oscillatory-field technique for reducing transit-time broadening is considered.