Effects of rare gas collision partner and pump energy on the four-level Cs exciplex pumped alkali laser

摘要

Experiments operating a Cs D2 line (852.1 nm: 6~2P_(3/2)→6~2S_(1/2)) laser, pumped by blue wing absorption of differentthermal Cs-rare gas ground state pairs, were analyzed. Using a 10 cm sealed gas cell, the D_2 line laser performance ishighest for Cs-Ar at 513K, and for Cs-Kr and Cs-Xe at 473 K. Overall, the highest optical-to-optical efficiency measuredwas 1.1% with a linear slope efficiency of 1.5% for the Cs-Ar collision pair at 513 K. All three Cs-rare gas mixtures showa D2 line laser performance increase with temperature towards a peak efficiency, followed by a decrease as temperature isincreased beyond the peak performance point. At lower temperatures ≤453 K the efficiency was highest with Cs-Xe, at473 K highest with Cs-Kr, whereas at higher temperatures ≥ 493 K the efficiency was highest with Cs-Ar. Measurementof the reduced absorption coefficient for the peak of the blue satellite of the different collision pairs resulted in values of1.2∙10~(-36) cm5 for Cs-Ar at 836.7 nm, 2.0∙10~(-36) cm~5 for Cs-Kr at 841.1 nm, and 3.0∙10~(-36) cm~5 for Cs-Xe at 842.7 nm.Simulations of the data using the detailed BLAZE Multiphysics™ software suite were also performed, which aid in theunderstanding of the basic physics behind the XPAL system. The simulations indicate that energy pooling significantlyinhibits laser performance at higher temperatures above 500 K.