Closed Loop, Depolarized Interferometric Fiber Optic (IFOG) Gyroscope with Self Adjusting Serrodyne Phase Nulling.

An interferometric fiber optic gyroscope employing an integrated, width polished, optic chip containing annealed proton exchange waveguides and a Mach-Zehnder interferometer for sensing a ramp induced signal from loop closing electronics to achieve a highly improved gyroscope scale factor linearity and dynamic range. An edge light emitting diode (ELED) operating at 1.3 micron wavelength is employed as the light source in the gyroscope. A decorrelator optical fiber segment is employed between the light source and the chip, and a Lyot depolarizer optical fiber segment is employed between the chip and one side of the fiber optic coil. Also, an intermediate output of the loop closing electronics is shown to have reduced scale factor sensitivity to light source wavelength change.
Supersedes PAT-APPL-534 202-90.