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:
Oct. 13, 1992
Filed:
Nov. 26, 1991
Stanley A Fisher, Boyds, MD (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
An omni-directional hydrophone having a pair of fiber-optic windings wrapped around a resilient ball to form a spherical acoustic sensor is provided. The fiber-optic pair has a first fiber which has a bonded jacket and a second fiber which has an unbonded jacket. The fiber with the bonded jacket is sensitive to both vibration of the mounting structure and impinging acoustic signals. The fiber with the unbonded jacket is sensitive to vibration but insulated from the acoustic signals. By comparing the signals from the two fibers, the hydrophone detects acoustic signals by detecting the phase difference between the two fibers. As both fibers are equally affected by vibration, there is no phase difference caused by vibration. This mechanization permits the canceling of vibration induced signals while retaining full sensitivity to acoustic signals. The hydrophone uses a standard fiber-optic laser source and detection system to convert the acoustic generated phase change to amplitude dependent voltage signals. The hydrophone is pressure and temperature insensitive.