Experimental Study of the Fine-Structure Mixing of Cs 62P Induced By Collisions with Different Buffer Gases
摘要
Fine-structure collisional transfer cross-sections for the 62P3/2 → 62P1/2 transition of caesium atoms in CH4, C2H6, CH4 + Xe, and C2H6 + Xe buffer gases were measured within the temperature range of 323–443 K using laser-induced fluorescence spectroscopy. The experimental results indicate that Cs(6PJ) atoms in C2H6 + Xe buffer gas exhibited the largest transfer cross-section in the 323–403 K temperature range. At 373 K, the fine-structure transfer cross-sections of Cs atoms in CH4 and CH4 + Xe gases were determined to be (11.40 ± 1.71) × 10–15 cm2 and (21.03 ± 3.15) × 10–15 cm2, respectively. Similarly, at 383 K, the fine-structure transfer cross-sections of Cs atoms in C2H6 and C2H6 + Xe gases were measured as (11.85 ± 1.78) × 10–15 cm2 and (40.33 ± 6.05) × 10–15 cm2, respectively. Charging with 24-Torr Xe gas increased the fine-structure transfer cross-sections in CH4 and C2H6 gases by approximately 1.8-fold and 3.4-fold, respectively. Introducing Xe gas into CH4 or C2H6 at 300 Torr within the 363–383 K temperature range markedly enhanced the D1 and D2 fluorescence intensities of the Cs atoms. The large collisional broadening coefficient of Xe contributed to improving the absorption efficiency of Cs atoms towards pump light. The experimental results presented in this study provide robust data support for enhancing the output performance of Cs-DPAL lasers under buffer gas pressures up to 500 Torr and enable effective validation of the relevant theoretical models.