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. 20, 1987
Filed:
May. 18, 1984
John P Dakin, Burridge, GB;
Plessey Overseas Limited, Ilford, GB;
Abstract
An optical sensing arrangement suitable for the detection of acoustic waves and/or temperature or magnetic field changes, comprises a laser light source for producing polarized light which in operation of the arrangement will be applied for detection purposes to the input end of an optical sensor for transmission therethrough, whereby a relative phase delay is produced between orthogonal components of the polarized light at the output end of the optical sensor, characterized in that a relative phase delay compensation device is optically coupled to and so orientated with respect to one end of the sensor, that the relative phase delay between the orthogonally polarized components transmitted through the compensation device and the corresponding relative phase delay of these components in the optical sensor are mutually opposite, thereby reducing the noise content of an output signal derived from the arrangement and fed to polarization analyzer for producing an indication of structural changes which have occurred in the optical sensor.