Patent ID: 6480638
Filing Date: 2002-11-12
Classification: G01N,G02B

Abstract:
A fiber optic sensor comprising:a light emitting member; a light splitter member, said light emitting member being positioned to insert light into said light splitter member; a first fiber optic coupler having an input optical fiber member and an optical fiber member having a waist region; a first output optical fiber member emerging from said first fiber optic coupler waist region, said light splitter member being positioned to insert light into said first fiber optic coupler input optical fiber member; a reference fiber optic coupler having an input optical fiber member and an optical fiber member having waist region, said reference fiber optic coupler being enclosed in a potting medium; a reference output optical fiber member emerging from said reference fiber optic coupler waist region, said light splitter member being positioned to insert light into said reference fiber optic coupler input optical fiber member; a light measuring member optically coupled to receive light emitted from said first output optical fiber member and said reference output optical fiber member; and sum difference means for processing the measured light emitted from said first output optical fiber member and from said reference output optical fiber member whereby the value derived from said measured light emitted from said first output optical fiber member is independent of variations in light from said light emitting member.