Thermal conductivity and management in laser gain materials: A nano/microstructural perspective

Abstract

Heat generation and thermally induced failure has been a major challenge for high-power applications in solid state lasers. Improvements in the solid state laser ceramic fabrication process offer improved mechanical toughness and comparable thermal conductivity compared to single crystal counterparts. Equally enticing is the possibility of using materials with intrinsically superior thermal/mechanical properties that are not viable in the single crystal form. Here, we review the nano/microstructural effects on optical, thermal, and mechanical properties of polycrystalline ceramics, recent developments in a variety of commonly used crystalline laser materials, and potential future directions for more robust laser gain materials for high-power applications. It is argued that the engineering microstructure with both optical and thermal performances in mind might offer breakthrough improvements in laser gain media.