Polarization-independent liquid-crystal optical attenuator for fiber-optics applications

A compact low-power low-voltage polarization-independent electrooptic attenuator has been developed using planar calcite elements and a standard twisted nematic liquid-crystal cell. A dynamic range of 31.5 dB and an insertion loss of 0.87 dB have been demonstrated with the attenuator interposed between a GaAlAs laser and a 0.20-N.A. multimode optical fiber.