Patent ID: 6366722
Filing Date: 2002-04-02
Classification: G02B

Abstract:
An optical waveguide sensor comprising:a core having at least one long period grating disposed therein wherein each long period grating has a plurality of index perturbations spaced apart by a periodic distance &Lgr;, wherein the periodic distance is 10 &mgr;m&lE;&Lgr;&lE;1500 &mgr;m; an inner cladding region surrounding the core and comprising a plurality of spaced apart first cladding features disposed within a first cladding material, wherein the inner cladding region has an effective refractive index; an outer cladding region surrounding the inner cladding region wherein the outer cladding region comprises a plurality of spaced apart second cladding features disposed within a second cladding material, wherein the outer cladding region has an effective refractive index; and wherein the total effective refractive index of the inner cladding region and the outer cladding region is approximately equal to but not greater than the effective refractive index of an environmental parameter to be sensed.