Abstract

One limitation on high resolution laser spectroscopy lies in establishing a reliable frequency scale. We report an offset-locked heterodyne spectrometer employing two cw tunable dye lasers, which has a fast response, frequency agility, and an absolute accuracy in the kilohertz range. The application of this device has been demonstrated by exploring the hyperfine structure of the sodium D1 line. The splitting of the ²s_1/2 ground state, which was already known from radio frequency measurements, was determined as a check of correct operation. A new measurement was made of the splitting of the ²P_1/2 excited state.

© 1994 IEEE