title: Study on photoionization in a rubidium diode-pumped alkali laser gain medium with the optogalvanic method.
abstract: We use the optogalvanic method to calculate the concentration of rubidium ions produced by photoionization in a Rb diode-pumped alkali laser gain medium. With bias voltage added across the electrodes of a rubidium hollow cathode lamp, the measured optogalvanic current is 2.3×10(-7) A. Further study shows that the rubidium ion concentration is proportional to the pump intensity, and the drift velocity of rubidium ions is proportional to the bias voltage. When the photoionization process reaches dynamic equilibrium, the rubidium ion concentration will not increase with growing rubidium atom density. The calculated rubidium ion concentration is 1.5×10(5)-10(6) according to the experiment, and the ionization degree is less than 2.4×10(-7).
authors: College of Opto-electric Science and Engineering, National University of Defense Technology, Changsha 410073, China. gelun86@yahoo.cn
authors: Lun
authors: L
authors: Ge
authors: Weihong
authors: W
authors: Hua
authors: Hongyan
authors: H
authors: Wang
authors: Zining
authors: Z
authors: Yang
authors: Xiaojun
authors: X
authors: Xu