Analyses of transmission characteristics of Rb, 85Rb and 87Rb Faraday optical filters at 532 nm

In this paper, the transmission characteristics for Rb, 85Rb and 87Rb Faraday optical filters at 532 nm that can be used to detect the practical and important frequency-doubled Nd:YAG laser are analyzed and discussed. The theoretical model of an excited-state Faraday optical filter based on the hyperfine structures of atomic system in the intermediate field, what is to our knowledge, is firstly reported. This model predicts that the peak transmission is approximately 50% with an equivalent bandwidth of less than 3 GHz for filters operating on the 5P1/2 → 10S1/2 transition in Rb, 85Rb and 87Rb vapors, respectively. Moreover, the transmission property of 87Rb atomic vapor is superior to that of Rb, 85Rb atomic vapors, which makes it more suitable for the operation material of Faraday optical filters by comparison with natural Rb vapor.