Patent ID: 6351310
Filing Date: 2002-02-26
Classification: G01C

Abstract:
An interferometric fiber optic gyroscope (IFOG) system comprising:a fiber sensing coil; a light source emitting light with an associated light source intensity, said source having a front output and back output; an optical coupler attached to said front output for receiving said light from said light source, said coupler creating two substantially equal intensity light beams for simultaneous transmission into said sensing coil said coupler attached to said coil; wherein said fiber sensing coil supplies return light to said coupler from said equal intensity light beams and said coupler combines and interferes said return light into a combined light beam; an optical phase modulator having a phase modulation amplitude, said modulator coupled to said coil; an oscillator coupled to said modulator said oscillator producing a periodic voltage which controls said phase modulation amplitude; light detection means for detecting and converting said combined light beam into an electrical current, said combined light signal transmitted through said light source and received by said detecting means coupled to said light source at said back output; an electrical amplifier coupled to said detector for converting said current into an electrical voltage; a direct current block, a rectifier, an integrating comparator, and light source drive means coupled to said amplifier, for controlling said associated light source intensity; and electrical signal processing means coupled to said amplifier for processing said voltage and providing an output signal proportional to the angular rotation rate input of said sensing coil, wherein the output signal is substantially temperature-independent.