Abstract

Magneto-optic atomic line filters known as Faraday filters have been shown to offer near- unity peak transmission and ultra-narrow passbands at discrete wavelengths associated with atomic transitions. The filters consist of an atomic vapor immersed in a longitudinal magnetic field, sandwiched between crossed polarizers. The field causes a resonant circular birefringence in the vapor near strong transitions, such as those near 455 and 852 nm in cesium For underwater lidar applications, blue cesium¹ and calcium² filters have been demonstrated. In this paper, we report the gated operation of a two-inch aperture, wide field-of-view cesium Faraday filter with a 20 ns risetime achieved by switching the magnetic field.

© 1993 Optical Society of America