Optical Pumping by Lasers in Atomic Frequency Standards

Abstract

Summary Single-mode, near-infrared diode lasers may improve the performance of atomic frequency standards. In the case of rubidium standards, the short-term stability may be improved by using laser diodes for optical pumping in place of conventional rf-excited lamps. In cesium beam standards, the lasers may replace both sets of state selection magnets, resulting in signal-to-noise, more reliable beam detection, easily reversed beam direction for cavity phase shift measurement, reduced Majorana transitions, and a smaller, more easily regulated C-field. The degree to which these improvements are realized depends upon the characteristics of available lasers. In this paper, we report measurements of laser intensity and frequency noise and their effects on clock performance. The light shift in a laser-pumped Rb clock is given, as well as the stability curve for that clock. Preliminary work on optical pumping in a cesium beam is also reported.