Rubidium Stark anomalous dispersion optical filter

Abstract

A Stark anomalous dispersion optical filter (SADOF) is an ultra-narrow bandwidth optical filter for applications in laser remote sensing and satellite laser communications. A SADOF consists of an atomic vapor cell between crossed polarizers subject to a dc electrical field transverse to the optical path and oriented 45° relative to the crossed polarizers. When linearly polarized light travels through a rubidium atomic vapor cell, a polarization rotation occurs (Stark induced birefringence). Large rotation angles may be obtained when the input light frequency is near the resonant frequencies of the atomic vapor. The transmission peaks of the SADOF correspond to frequencies that have rotation angles of odd integer multiples of π/2 and low absorption in the vapor cell. The transmission curve depends on the electric field and atomic density, and the optimum conditions for a rubidium SADOF are found through theoretical calculations that include both Stark spectral and polarization rotation. We will present theoretical SADOF transmission curves for several green rubidium transition frequencies.