ABSIRACT Natural rubidiuui is a mixture of the two isotopes, Rb arid 87D Taking into account their hyperfine structure, and using a quantum-ichanica1 treatment of the resonant Farac effect, we calculate the transaission, central frequency shift and pass bandwidth of Rb 7&kii Faradar Zeen optical fi Iter, as functions of ngnetic field strength and atomic cel I temperature.key wcré: Faraday ano1oi. dispersion, atomic filter, Zeein effect.
I . IWRODUCFIONFaray anomalous dispersion optical filter(FADOF) is based on the anoi1ous dispersion near the resonant absorption lines of the sample atone in a longitudinal gnetic field. It has such advantages as tunable working wavelength, narrow bandwidth,high transmisson in the ps band and high noise rejection ratio out of the passbancj, and short response time,etc. .It may be usable to probe the weak signal buried in the intense solar background. Because of tunable working frequency, early applications of FADOF were to high-speed optical modulation, dye-laser frequency locking.6The transiissicn of essential FiX3F depends on the number density( N) of ato in the vapor,oscillator strength(f),interaction lerigth(L), and the strength of the axial field(B).Jn 1972,D.}4.Camm and F.L.Curzon1 theoretically analysed and experi.entally observed the Faracy resonant effect. Yeh developed a theoretical frameiork for calculating essential filter characteristics2. More resently, FADOF's based on groundstate transitions in a1ka1i-tal vapors were developed3. But most essential FAD€F's are ilti-peaky in their pass banth,due to atomic hyperfine structure and secondary peaks caused b increasing external gnetic field.The model presented in this paper can reduce some secondary peaks. Its bandwidth is more narrow, because ny secondary peaks of the filter can be re*wed by adding another cell containing the same atomic vapor in a stronger gnetic field. The gnetjc field B in the second cell is chosen so that the new absorption line in the second cell coincides with the undesirable passband.Note that the anomelous dispersion spectrum in the first cell is not symetric with respect to the atomic line center v =0In this paper ,in consideration of the hyperfine structures of 85 and 87J I)z lines and b using a quanturichanical treatment ,the transmission characteristica of the Faraday-Zeemen optical filter (FZOF) as functions of megnetic field strength and atomic cell temperature, are calculated and coared with that of the essential Faraday filters. Important features such as peak transmission, bandwidth, and assband tuning capabilities will be derived.
2.IIIEORETICAL MODELThe basic model of Faraday-Zeemeri optical filter (FZOF) is shown in Fig. 1. Px and Py are two O-8194-2290-8/96/$6.QO SPIE Vol. 2889 1159 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/28/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx
