Ultra-Narrow Faraday Rotation Filter at the Rb D1 Line

TL;DR

This paper reports the development and analysis of an ultra-narrow bandwidth Faraday filter at the rubidium D1 line, achieving high transmission and narrow bandwidth suitable for precise optical filtering applications.

Contribution

It provides both theoretical modeling and experimental validation of a FADOF at the Rb D1 line with superior performance metrics.

Findings

71% transmission achieved

445 MHz bandwidth realized

1.2 GHz noise equivalent bandwidth

Abstract

We present a theoretical and experimental study of the ultra-narrow bandwidth Faraday anomalous dispersion optical filter (FADOF) operating at the rubidium D1 line (795 nm). This atomic line gives better performance than other lines for the main FADOF figures of merit, e.g. simultaneously 71% transmission, 445 MHz bandwidth and 1.2 GHz equivalent noise bandwidth.