Diamond/Sapphire Gain Element for Modelocked Backbone Laser

摘要

An integrated diamond sapphire laser design was explored using analytical expressions, computer based simulation, and experimentation. The analytical expressions and computer based simulation predicted a solid state laser gain medium composed of diamond for removing heat and Ti:sapphire for gain could access the high average power densities required for high energy lasers satisfying requirements of the JTO program. The experimental efforts indicated that single crystal diamond could be fabricated with the required surface properties for implementation of the basic diamond/Ti:sapphire component. The task of experimentally measuring thermally induced refractive index change was found to call for parallelepiped shaped samples. Given the expense of procuring diamond in the required shape and size the experimental investigation was performed with Ti:sapphire as the gain material and undoped sapphire as the cooling material. The experimental study demonstrated that the most important physical requirement, heat removal across the interface between the gain sample and the cooling sample with a negligible temperature change across the interface could be obtained by proper preparation of the interface surfaces. A means of optically measuring the dynamics of the thermally induced temperature change, including the change across the interface was developed.