Ultranarrow bandwidth nonlinear Faraday optical filter at rubidium D2 transition

We demonstrate a narrowband optical filter which operates on the 52S1/2 to 52P3/2 transition at 780 nm in rubidium vapor based on optical-pumping-induced dichroism combined with Faraday anomalous dispersion effects. Its peak transmission is 18.4(2)% at the 52S1/2, F = 2 to 52P3/2, F ' = 1, 3 crossov