US Patent 11199462 Fiber optic pressure sensor

A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.