Patent ID: 7068868
Filing Date: 2006-06-27
Classification: G02B

Abstract:
1. A sensing device, comprising: a fiber having a core and a cladding; a fiber sensor in the fiber comprising a side surface on fiber cladding of the fiber within a reach of an evanescent field of guided light in the fiber, and an overlay waveguide on top of the side surface to extract light out of the side surface; said overlay waveguide having a planar surface including a coupling region along a length of said fiber for said extraction of light, where said overlay waveguide coupling region is substantially thicker than said fiber core; a housing unit having a chamber to hold the fiber sensor and a movable diaphragm in the chamber to transmit pressure to the fiber sensor in response to a pressure applied to the diaphragm; an optical detector to receive light in the fiber that transmits through the fiber sensor; and a signal processor to process output of the optical detector and to determine the pressure on the diaphragm.