An Optical Heterodyne Experiment on Stars

Abstract

Measurements on a number of bright stars have indicated the existence of a rf (mixing) signal caused by optical mixing of laser and star light. The magnitude of this signal is in reasonable accordance with theory. The equipment used consists of a He–Ne laser operating at 6328 Å, a high-speed photocell and suitable rf power measurement equipment. Measurements have been made at a fixed laser frequency; no spectral scan has been attempted as yet.