The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 1991
Filed:
Jun. 16, 1983
Applicant:
Inventor:
Charles K Asawa, Pacific Palisades, CA (US);
Assignee:
TRW Inc., Redondo Beach, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ; G02B / ; G02B / ;
U.S. Cl.
CPC ...
455612 ; 350 9615 ; 455602 ;
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.