Optical fiber with an acoustically sensitive fiber bragg grating and ultrasound sensor including the same

Abstract

The optical fiber with an acoustically sensitive fiber Bragg grating includes an optical fiber core with a pair of fiber Bragg gratings formed therein, such that each of the fiber Bragg gratings is spaced apart from the other. A cladding material is disposed on and surrounds at least a portion of the optical fiber core. The cladding material has at least one material property associated therewith, where the at least one material property may be a smaller Young's modulus than a Young's modulus of the optical fiber core, a larger photo-elastic coefficient than a photo-elastic coefficient of the optical fiber core, or combinations thereof. An ultrasound sensor includes at least one of the optical fibers embedded in a polymer layer, along with a backing layer and an acoustic matching layer.