Research On Immersed Slab Laser And It’s Thermal Management

Thermal-induced problems have long been the bottleneck for the development ofhigh power solid state lasers. And the thermal management technologies are one ofthe hottest topics of laser technology. A novel idea named “immersed slablaser”——solid lasers cooled directly with flow was proposed, aimed at developing anew technology to achieve improved thermal management by the means of exportingthe useless heat effectively.In this article, comparison and contrast had been made to the thermalmanagements of solid bulk lasers, liquid lasers and the “immersed-in-liquid coolingand distributed gaining lasers” in the background details. A proper coolant wasscreened, slabs oriented at BreWster’s angle relative to the laser emission axisimmersed in coolant liquid was demonstrated. Based on the rate equation for thefour-level laser system，the output energy and relevant factors that affect the laseroutput are derived. And for the coupled thermal effects between the coolant liquidand the solid happened in fluid state laser pumped, and the thermal-flow-solidcoupling model are established by fluent6.3.26. Thermal, fluid dynamics underdifferent Flow rates and pumped energy was researched. The Wavefront aberrationunder simulated distribution of temperature field of gain region conditions of liquidcooling distribution gain region is analyzed.In the experimental stage, dispersion curve and the temperature refractivecoefficient of the coolant, absorption spectra, fluorescence spectra of Nd:YAG aretested; Oscillator with Slabs oriented at BreWster’s angle immersed in coolant wasbuilt. Coupling efficiency for the pumping system, and the slope efficiency, pulsewidth, far-field pattern of the output laser were gained in the experiment. Maximum multimode output energy of0.653J at1064nm was achieved with a optical–opticalefficiency of25%, with a pump energy of2.66J at808nm. The coefficient ofvariance(cv) of the output energy index of output uniformity is1.1%which showsgood performance of thermal management. The research about” verified the outputCapacity and thermal management efficiency of the Oscillator for configuration of“thin slab immersed laser”, laid the foundation for further study of this configurationlasers...