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:
Jan. 16, 1996
Filed:
Apr. 15, 1994
Applicant:
Inventors:
Peter Healey, Ipswich, GB;
David Smith, Woodbridge, GB;
Assignee:
British Telecommunications public limited company, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
359112 ; 359110 ;
Abstract
A monitor unit for detecting physical interference of a communications fibre in a transmission system includes a monitor circuit coupled to the communications fibre. A portion of a signal being transmitted along the communications fibre is coupled out of the fibre and into the monitor unit. A filter allows only one of two orthogonal polarization field components to pass through it to the monitor circuit. By detecting fluctuations in the polarization state of the filtered optical signal, the monitor circuit allows the detection of external influences to be determined.