IFOG modulation technique for real-time calibration of wavelength reference under harsh environment

摘要

An interferometric fiber optic gyroscope (IFOG) includes a fiber light source, a multi-function integrated optic chip (IOC) and corresponding fiber sensing coil, and a wavelength division multiplexor connected to each other via a coupler, along with servo loop closure processing electronics. In addition, an absolute wavelength reference, such as an atomic reference, that is not susceptible to drift or effects of radiation, is connected to the wavelength division multiplexor. Periodically and momentarily, and for purposes of calibrating the wavelength division multiplexor, gyro return light from the IOC, which is normally passed to the wavelength division multiplexor, is suppressed in favor of a signal supplied by the absolute wavelength reference.