Isotope ⁸⁷Rb Faraday filter with a single transmission peak resonant with atomic transition at 780 nm

Abstract

We demonstrate an isotope ⁸⁷Rb Faraday anomalous dispersion optical filter (FADOF) with a single transmission peak resonant with the 5S_1/2, F = 2 → 5P_3/2, F' = 1, 2, 3 transitions at 780 nm with an enriched ⁸⁷Rb isotope at low temperature. The isotope ⁸⁷Rb FADOF achieves a single peak transmission of 74.8% with a bandwidth of 0.96 GHz. Compared with most of FADOFs operated at frequencies far from absorption, the isotope ⁸⁷Rb FADOF that we have achieved can provide a transmission band exactly covering atomic transitions for many practical applications.