White Paper: Increased Efficiency And Performance In Laser Pump Chambers Through Use Of Diffuse Highly Reflective Materials

By Labsphere, Inc.

The use of diffuse reflectance materials in laser pump reflector design can lead to significant improvements in laser performance over reflectors employing more traditional, specular (or mirror-like) reflectors. Diffuse reflectors provide a more predictable and uniform beam profile, and reduced susceptibility to parasitic oscillations. Since laser pumping involves multiple reflections within the pump chamber, the efficiency of a laser pump chamber can be significantly affected by relatively small changes in reflectance. For example, a chamber with a reflectance factor of approximately 99% over the 400 to 1000 nm range, can provide a 15% gain in performance over a comparable 98% reflective chamber, even though the reflectance factor is only 1-2% lower. Much larger gains are possible over typical ceramic reflectors. This paper will examine high performance PTFE as a reflector in laser pump chambers compared to other materials. Gains in performance through reflectance and diffuseness are shown through mathematical models, experimental results and real world case studies.