OBSERVATION OF OPTICAL RAMSEY FRINGES IN THE 10 µm SPECTRAL REGION USING A SUPERSONIC BEAM OF SF6

Abstract

We report a first observation of optical Ramsey fringes in the 10 µm spectral region using a supersonic seeded beam of 7% SF6 in He, illuminated by a CO2 laser in spatially-separated field zones. We have used either three standing waves or four travelling waves and obtained highly contrasted fringes with a 23 kHz half-width corresponding to a 5 mm distance between zones