Narrowband tunable filter based on velocity-selective optical pumping in an atomic vapor

TL;DR

This paper presents a tunable, narrow-band optical filter using velocity-selective optical pumping in rubidium vapor, achieving high extinction and tunability within the atomic resonance, suitable for atom-photon interaction applications.

Contribution

The work introduces a novel tunable atomic filter based on optical pumping-induced circular dichroism, with practical tunability and high out-of-band extinction.

Findings

Peak transmission of 14.6% achieved

Linewidth of 80 MHz demonstrated

Tunable within the Doppler linewidth range

Abstract

We demonstrate a tunable, narrow-band filter based on optical-pumping-induced circular dichroism in rubidium vapor. The filter achieves a peak transmission of 14.6%, a linewidth of 80 MHz, and an out-of-band extinction >35 dB. The transmission peak can be tuned within the range of the Doppler linewidth of the D1 line of atomic rubidium at 795 nm. While other atomic filters work at frequencies far from absorption, the presented technique provides light resonant with atomic media, useful for atom-photon interaction experiments. The technique could readily be extended to other alkali atoms.