Abstract

Nonlinear Faraday rotation (NFR) was studied for ⁸⁷Rb atomic D₂ F_g = 2−F_e =1,2,3 transitions with crossed polarizers, with varying longitudinal magnetic field strength B = 0 – 10 G. The experiment was realized in counter-propagating beam Doppler-free geometry. Our results were obtained for forward probe beam power (P_FW −150 μW) higher than the backward pump power (P_BW ~30 μW) to induce a large value of Faraday rotation and eliminate the influence of polarization rotation due to pump induced anisotropy in the absence of magnetic field. This enabled the first observations of NFR for each hyperfine and crossover resonances. Fig. 1 shows our experimental configuration and experimentally obtained spectra. The zero frequency spectrum of (a) corresponds to the F_g = 2−F_e=1 transition. For closed F_g = 2−F_e=3 transition the signal has a nearly "W-shape", while the signal shape for crossover resonances F_g = 2−F_e=2,3 (C023) and F_g = 2−F_e=1,3 (COB) is nearly dispersive.

© 2007 IEEE