Abstract

We report a transmission-gated rubidium Faraday filter^1,2 with an 80 ns rise time, a 500 ns pulse duration, and a transmission greater than 50% for unpolarized light. The filter operated at 780 nm and had an effective optical bandwidth of approximately 2.5 GHz. Our filter consisted of a rubidium vapor cell located between crossed polarizers with a uniform magnetic field along the optical axis (Fig. 1). The vapor cell was 50 mm long and 25 mm in diameter and heated to a temperature of 130<198C. A single-turn Helmholtz coil surrounding the cell produced the magnetic field for the necessary polarization rotation within the vapor. A high voltage discharge circuit created the current pulse within the Helmholtz coil. The transmission was measured with a single-mode laser diode tunable around the 780 nm atomic resonance.

© 1993 Optical Society of America