MULTI-FUNCTIONAL FIBER OPTIC FUEL SENSOR SYSTEM BASED ON PHOTONIC MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a fuel sensor system using fiber optics for sensing properties (such as the level, density, temperature and chemical composition) of liquid fuel in a fuel tank.SOLUTION: A fuel sensor system utilizes a fiber optic sensor comprising a membrane 12 made of a direct band gap semiconductor material (such as gallium arsenide) that forms an optical cavity with an optical fiber 8a inside a hermetically sealed fiber optic package 4 located at the bottom of a fuel tank 50. The optical fiber inside the fuel tank is not exposed to the fuel. The optical cavity formed by the bottom surface of the membrane and the surface of the distal end of the internal optical fiber functions as a Fabry-Perot interferometer. Multiple light sources 32, 38 operating at different wavelengths and multiple spectrometers 40, 36 are coupled to the confronting surface of the membrane via the optical fiber inside the fuel tank, a hermetically sealed fiber optic connector 14 that passes through the wall of the fuel tank, and a fiber optic coupler 28 located outside the fuel tank.SELECTED DRAWING: Figure 1