Patent ID: 7514670
Filing Date: 2009-04-07
Classification: G01D,G08B

Abstract:
1. A spatially distributed sensor system, comprising: an optical transmitter; an optical conduit optically coupled to said optical transmitter at an input position; a spatially distributed sensing element optically coupled to said optical conduit at a position along said optical conduit spatially separated from said input position, an optical receiver coupled to said optical conduit to receive at least a portion of light from said optical conduit that includes light returned to said optical conduit from said sensing element, wherein said optical transmitter comprises a laser and a depolarizer to provide depolarized light to input into said optical conduit, and wherein the sensing element comprises an optical path defined by (1) a polarizer disposed between and optically coupled to the optical conduit and a first end of a length of optical fiber and (2) a reflecting element disposed at and optically coupled to a second end of the optical fiber so that depolarized light is polarized along the optical path before being returned to the optical conduit, and the state of the at least one sensing element is determinable from the polarization properties of light transmitted to the optical receiver via the optical conduit based on changes in the birefringence of the optical fiber in the optical path.