Research/Patents/US 5003623
US 5003623

BIMODAL INTRUSION DETECTION IN AN OPTICAL FIBER COMMUNICATION SYSTEM USING GRADED INDEX FIBER

Assignee

TRW INC., A CORP.OF OH

Filed

Jun 16, 1983

Granted

Mar 26, 1991

Location

Redondo Beach CA (TRW)

Abstract

An intrusion-alarmed optical communication system in which two separate modal groups are launched into a single graded index transmission fiber. The system includes two light sources and a lens to focus the light sources into the transmission fiber. A spatial filter is used to selectively limit the angles of incidence of the light on the fiber, and operates in conjunction with the lens to launch light from one source at appropriate angles and points of excitation to excite higher-order modes in the fiber, and to launch light from the other source at appropriate angles and points of excitation to excite lower-order modes in the fiber.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Nov 29, 1983

Rescinded

Mar 23, 1990

Duration

6 years, 3 months

Inventor

  • 1CHARLES K. ASAWA

Sensitive facility: Redondo Beach CA (TRW)

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records