The Effect of 3.39 Micron Superradiance on the 0.6328 Micron Output Power of a Helium-Neon Laser

摘要

The effect of competition in a 0.6328 micron helium-neon laser from the high-gain 3.39 micron line has been studied. The 50 milliwatt laser used for the investigation employs a six-foot Brewster-angle tube and has a prism at one end to insure that oscillation occurs only at 0.6328 microns. Measurements were made of the 3.39 micron superradiance from one end of the tube when various calibrated reflectors were placed at the other end. With a typical dielectric coated mirror, designed for maximum reflectivity at 0.6328 microns, the superradiant 3.39 micron power from the other end of the tube was 75 microwatts. This result shows that in a 6 foot visible laser filled with a 10:1, He(3)-Ne mixture and employing a single prism for frequency selection, the 3.39 micron superradiance does not significantly affect the visible output power. However, the superradiance is about 2 orders of magnitude larger than estimated from theory, and presumably results mainly from multiple reflections from the tube walls. (Author)