Optimization of room-temperature continuous-wave Cr4+-doped solid-state lasers: experiment and modeling

I describe the results of a novel study which employs experimental and theoretical methods to determine the optimum crystal and resonator parameters for Cr⁴⁺-doped lasers subject to lifetime thermal loading. The procedure consists of two parts. In the analysis, the results of pump absorption saturation, lasing threshold, and power efficiency measurements are compared with the predictions of a theoretical model to determine the laser cross sections. This model performs pump transmission and output power calculations by accounting for heat generation in the crystal, temperature dependence of the fluorescence lifetime, saturation effects at the pump and lasing wavelengths, and excited-state absorption at the lasing wavelength. In the second part of the procedure, numerical optimization studies are performed by using the best-fit cross-section values to determine the optimum crystal absorption, crystal length, and resonator reflectivity which maximize the output power