Effects of high-level energy pumping on radiative thermal loading of phosphate laser glass

Lasers have been employed as an ignition source for explosive detonation and combustion initiation. The radiative heat absorption in the energy pumping process is expected to alter laser optical conditions and thus affects their performances. The objective of the current research is to establish various thermal and performance characteristics of a solid-state laser designed for explosive detonation under high-level energy pumping, which include maximum temperature change, temperature rise rate, lasing delay, pulse period, etc. Some characteristics of high-level pumping are also compared with those of low-level pumping. A modified Michelson interferometer is employed together with a high-speed framing camera for gross-field detection and photo-detectors for pulse observation, respectively. The interferometric technique appears to be useful for evaluating the thermal behaviors and surface irregularities of laser rods.