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

We demonstrate an isotope Rb Faraday anomalous dispersion optical filter (FADOF) with a single transmission peak resonant with the 5S , F = 2 → 5P , F' = 1, 2, 3 transitions at 780 nm with an enriched Rb isotope at low temperature. The isotope Rb 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 Rb FADOF that we have achieved can provide a transmission band exactly covering atomic transitions for many practical applications.