Abstract

We performed a careful study of a liquid nitrogen-cooled ruby laser and observed bistable switching from an axial cavity mode to an off-axis gain-guided mode. The ruby laser consisted of a 3.8-cm long pink ruby rod with a 6-mm diameter. One end face of the rod had a 100% reflecting dielectric coating, while the other face of the rod was polished and left uncoated. The ruby was cooled in a cold finger housed in a liquid nitrogen Dewar with broadband antireflection-coated windows. The rod was end pumped through the high- reflectivity side with the focused (20-cm focal length) multiline output of an argon-ion laser operating in the 0-5-W range.

© 1987 Optical Society of America