Modeling and analysis of buffer gas effect on 52S1/2→52D5/2 and 52S1/2→72S1/2 broadened two-photon pumped Rb vapor lasers

Abstract

The study introduces helium (He) as a buffer gas to theoretically investigate the characteristics of two-photon pumped Rb vapor laser (Rb-TPAL) in order to enhance the pumping absorption efficiency of Rb-TPAL and consequently achieve high-power laser output. The analysis is based on a three-dimensional computational model, incorporating the spectral distribution of pump and absorption, as well as the influence of He on the absorption spectrum. The theoretical calculation of the dependence of the 52S1/2 → 52D5/2 transition broadened as a function of the pressure of He has good agreement with experimental results. We also simulated the influence of the pump linewidth and pressure of He on the output characteristics when 52S1/2 → 52D5/2 and 52S1/2 → 72S1/2 transitions in Rb-TPAL. A comparative analysis revealed that opting for the 52S1/2 → 72S1/2 transition can achieve higher optical–optical efficiency. The results also substantiate that the addition of a small amount of He has a positive impact on the laser output, consistent with experimental findings. Our study is crucial for designing the high-power multi-wavelength output Rb-TPAL system.