The design and operation of a 10 kW solid-state heat-capacity laser

Summary form only given. We have developed and demonstrated a new operational mode for solid-state laser systems in which the cooling of the gain medium is separated in time from the lasing cycle. In heat-capacity operation, no cooling takes place during lasing. The gain medium is pumped very uniformly and the waste heat from the excitation process is stored in the solid-state gain medium. By depositing the heat on time scales that are short compared to thermal diffusion across the optical aperture, very high average power operation is possible while maintaining low optical distortions. After a lasing cycle, aggressive cooling can then take place in the absence of lasing, limited only by the fracture limit of the solid-state medium. This mode of operation is ideally suited for applications that require 1-30 s engagements at very high average power. In order to demonstrate the operation of a high average power heat-capacity laser system, we have developed a flashlamp-pumped Nd:glass laser with output energies in the range of 500-1000 J/pulse in a 10/spl times/10 cm/sup 2/ beam.