Patent Number: 6,434,283

Title: In-line fiber-optic polarizer

Abstract: A fiber-optic acoustical sensor system includes a light source, an elongate optical cable conducting light from the light source to an optical acoustical transducer located at a distance from the light source along this cable, and a polarizer at the acoustical transducer. The sensor system includes a polarizer providing orthogonally-polarized light along the optical cable to the polarizer located adjacent to the transducer. Because of the polarizer adjacent to the transducer, disturbances of the optical cable and resulting polarization perturbations of the light transmitted along this cable do not affect the optical acoustical transducer. The acoustic transducer is responsive to sound energy to provide an optical return signal indicative of this sound energy. An in-line fiber-optic polarizer suitable for use in this acoustical transducer includes a pair of confronting optical fiber portions aligned along an optical axis and which each define end surfaces disposed at a Brewster polarizer angle with respect to light transmitted along this optical axis. The end surface of one of these optical fibers carries plural alternating sub-layers of high-index and low-index dielectric material, which are effective to p-polarize the transmitted light and substantially eliminate s-polarized light transmission to the optical acoustical transducer.

Inventors: Frederick; Donald Adam (Woodland Hills, CA), Hall; David Barnett (La Crescenta, CA)

Assignee: Litton Systems, Inc.

International Classification: F02B 77/04 (20060101); F16H 57/04 (20060101); F01M 11/04 (20060101); G02B 006/00 (); G02B 006/38 ()

Expiration Date: 08/13/2019