钙、锶、钡和汞离子激光中的共振辐射俘获效应

根据Holstein的共振辐射俘获理论，讨论了气体温度和辐射俘获下能级粒子数密度对辐射俘获上能级有效辐射寿命的影响，显示辐射俘获下能级粒子数密度是辐射俘获效应中的主导因素.计算了钙，锶，钡和汞四种离子七条共振-亚稳能级跃迁激光在不同电离率下产生共振辐射俘获效应的阈值条件，发现当电离率为5%时这类激光的出光温度与共振辐射俘获的阈值温度相一致，这与实验得出的电离率为3%—5%相符合.表明达到共振辐射俘获阈值条件是该类激光实现粒子数反转的重要因素.

Resonance radiation trapping in Ca, Sr, Ba and Hg ion lasers

According to Holstein's theory about radiation trapping effect, the influence of gas temperature and ground-state population density on the effective lifetime of the resonance level is discussed. The results show that the ground-state population density is the dominating factor in the radiation trapping effect. The threshold parameters of radiatoin trapping have been calculated for seven resonance metastable transition laser lines in Ca⁺, Sr⁺, Ba⁺ and Hg⁺ in different ionization ratios. The threshold temperature of radiation trapping was found to be consistent with the initial lasing temperature for the ionization ratio of 5%, which matches the ionization ratio of 3% to 5% observed in experiment. This consistency reveals that the threshold condition of radiation trapping effect is an important factor for population inversion in lastrs based on the ionic resonance to metastable transition.