Laser excited structured crystal phosphor waveguide for high power applications

Abstract

Single crystal phosphor, which is a transparent material, absorbs blue light and emits yellow light. As a result, it is the ideal material for conversion of blue laser light into yellow visible light allowing high efficiency, and high temperature operations. When fabricated into a waveguide, it provides a large volume and surface area for ease of heat sinking. The transparent property of the crystal phosphor material provides features are not available in other phosphor materials such as glass phosphor and ceramic phosphor in which the laser energy is all concentrated in a small spot with small thickness making heat removal very challenging. This paper presents an end-pumped structured crystal phosphor waveguide design such that the volume of laser absorption and heat dissipating surfaces are both larger with a small output cross-section for small etendue operations. Preliminary prototypes have been fabricated and tested with expected results. Several other structures and measurements will be presented.