Patent ID: 7714271

Claim:
A motion sensor for sensing motion in an environment, comprising: a main body having contact with a reference location where an environmental disturbance force having a disturbance magnitude may act upon said main body so as to cause said main body to react; a supporting fixture attached to said main body; a fiber optical feed cable passing axially through said supporting fixture, said fiber optical feed cable comprising: at least one optical fiber passing axially through said fiber optic feed cable, each of said at least one optical fiber having an intrinsic internal proof mass and being configured to allow light to propagate through said at least one optical fiber, each of said at least one optical fiber extending from a proximal end to a distal end away from said supporting fixture, said proximal end being attached to said supporting fixture, said distal end being not directly attached to other fiber or support and so being free to respond to a strain applied to said at least one optical fiber, said strain resulting from said environmental disturbance force acting on said intrinsic internal proof mass alone, each of said at least one optical fiber comprising at least one Bragg grating sensing element arranged within each of said at least one optical fiber and between said proximal end and said distal end, each of said at least one Bragg grating sensing elements being configured to respond to an optical signal and to respond to said strain; whereby when said environmental force acts upon said main body, said strain is applied to said at least one optical fiber and each of said at least one optical fiber bends under said strain thereby modulating said light so as to create an optical sensing signal related to said disturbance magnitude.