Patent ID: 8973445
Filing Date: 2015-03-10
Classification: G01L

Abstract:
1. A holographic pressure sensing apparatus comprising: an optical fiber having an end face, said optical fiber being a multimode optical fiber; a diffractive element at the end face of the optical fiber; at least one light source for transmitting through the optical fiber light comprising a first wavelength and a second wavelength; a light-coupling component separate from the optical fiber and offset from the diffractive element by a separation distance, said light-coupling component positioned to receive first and second images that are respectively formed by interaction with the diffractive element of said first and second wavelengths of light; a casing enclosing and connecting the optical fiber and the light-coupling component, said casing configured such that a change of pressure in a fluid surrounding said casing will displace the light-coupling component relative to the optical fiber; and first and second light sensors for respectively receiving from the optical fiber first and second reflected images respectively formed by reflection of said first and second images from the light-coupling component through the diffractive element; and wherein such relative displacement of the light-coupling component will adjust an overlap of the first and second images, such that a change in a measurement of said overlap will indicate a change of the pressure in the fluid surrounding the casing.