Patent ID: 6204921
Filing Date: 2001-03-20
Classification: G01C

Abstract:
A system for suppression of relative intensity noise in a fiber optic gyroscope utilizing a light source, the system comprising:a modulator for generating an intensity modulated light by modulating light emitted from said light source;a tap coupler for receiving said intensity modulated light and sampling a part thereof to provide a sampled signal;a photodetector for sensing said sampled signal as a current and converting said sampled signal to a detected signal having a voltage proportional to said current; andservo control logic, responsive to said detected signal, for generating an error signal to cause said modulator to vary the intensity of said light received from said light source to cancel out intensity fluctuations of the light at said photodetector, thereby suppressing said relative intensity noise, wherein said modulator, said tap coupler, said photodetector, and said servo control logic comprise a feedback loop which utilizes negative feedback to control said intensity fluctuations, and wherein said servo control logic comprises a voltage amplifier having characteristics such that the open loop gain of said feedback loop is greater than unity up to at least 800 kilohertz.