Abstract

Ion lasers are run in a single-longitudinal mode for use in a variety of experiments, the most significant being holography, One of the critical parameters in single frequency operation is the drift of the cavity length relative to the etalon spacing. For a temperature stabilized étalon, changes in the cavity length result in unpredictable mode hops and some absolute frequency shift. Typically, a well stabilized passive cavity will mode hop approximately once per degree Celsius temperature change, and drift on the order of 100-200 Mhz. Active systems have been discussed that can eliminate mode hops over a 2°C range but show >200-Mhz drift per 1°C change. In this paper we report on an active stabilization system that can maintain <30-Mhz/°C absolute frequency drift and no mode hops over a 5°C temperature range.

© 1992 Optical Society of America