INFLUENCE OF INTRACAVITY POWER ON FREQUENCY CHARACTERISTICS OF IODINE-STABILIZED He-Ne LASER

Following a shift in the industry to solid-state lasers during the past decade, resonator tubes which can be used in iodine-stabilized helium-neon (He-Ne) lasers are being discontinued by most manufacturers. After installing a replacement tube, it was discovered that its intracavity power was not equal to that of the original tube. The influence of this change on the uncertainty of frequency was determined over the course of several months. Mirrors in the optical cavity were adjusted for optimal intracavity power using short heterodyne beat frequency measurements with a reference laser. Data for stability and absolute value of the reference frequency were well-known and provided in advance by calibration with the comb method. The sensitivity coefficient of the output beam power was estimated from beat frequency deviations measured at several values of power inside the range of the stabile operation of the laser. Finally, a long-term measurement of beat frequency provided data about the stability and frequency offset.