Abstract

High power single longitudinal mode (SLM) operation of solid state lasers is limited by spatial hole burning within the gain medium. Unidirectional ring lasers reduce spatial hole burning and thus allow higher power SLM operation. Unidirectional operation is most commonly implemented through the use of an intra-cavity Faraday isolator. A simple alternative mechanism for implementing unidirectional operation is the use of an external HR mirror to feedback one of the cavity output directions into the other cavity direction [1]. We demonstrate the use of this technique in a bounce geometry ring laser system for the first time, producing a high power, high efficiency SLM laser. We enhance the efficiency with an additional pass through the amplifier. This represents a significant improvement in the simplicity of a unidirectional laser system based on a high gain amplifier and the highest average power SLM seen from a non-adaptive bounce geometry laser.

© 2009 IEEE