Abstract: A signal processing circuit for a fiber optic gyroscope which prevents glitches from saturating the photodetector and gain stages of the detection electronics by inserting random noise in the detected signal is disclosed. This technique allows one to control the noise density function, the noise level and the noise spectrum of the detected signal.

Abstract: A bias modulation amplitude monitoring system for a rotation sensor having a pair of output signal component detectors to provide magnitudes of the corresponding frequency components in that signal which are used by a component relationship determination arrangement capable of adjusting the output signal to have a selected value in a range of values for a selected rate of rotation thereof, and to correct variations therein.

Abstract: A digital synthetic serrodyne phase difference controller for a rotation sensor capable of sensing rotation about an axis of an optical fiber coil based on having a pair of electromagnetic waves propagating through the optical fiber in opposite directions to both impinge on a photodetector with a phase difference relationship therebetween, the digital synthetic serrodyne phase difference controller including a positive serrodyne generator and a negative serrodyne generator having outputs which input to a common adder. The bit output of the adder is converted to analog in a digital-to-analog converter and applied to operate a frequency translating device in the optical path with the coil.

Abstract: An integrating analog-to-digital converter system in which alternating and different combinations of signals are integrated, and which are selected for such integration both periodically and through an integrating result reaching a reference value in the periods. A digit count is provided as a system output indicating the time duration of integration of a selected signal combination in each period.

Abstract: An electrically passive fiber optic position sensor having a course measurement indicator and a fine measurement indicator combined to determine the overall position, whether linear or angular, of an object measured. The coarse measurement sensor depends on bending loss of optic fiber in one embodiment and on the Faraday effect in another embodiment. The fine measurement indicator depends on the Faraday effect in both embodiments. The invention avoids the problems of contaminated optics as the light need not leave the optic fiber.

Abstract: A phase difference controller for a rotation sensor based on a coiled optical fiber operating a dual output generator and signal combiner to provide a composite signal to operate a frequency translating device in the optical path with the coil. The combined signal of appropriate frequency and polarity operates the translating device to provide a phase difference shift in the optical path.