Digital Spectrometry Signal Treatment Applied to a Fiber Optic Resonant Gyroscope for Rate Measurements

Abstract

The FORG (Fibre Optic Resonant Gyroscope) opeeration principle uses a recirculating ring resonant cavity to get a rotation-induced Sagnac effect enhancement (cited by Ezekiel and Balsamo). It grants to a FORG a comparable sensitivity in relation an I-FOG (Interferometric Fibre Optic Gyroscope)that has the fiber lenght equal a half of finesse factor times longer. Other advantages is despite of thermal drift because the FORG uses less quantity of fibre than the I-FOG, giving to the first less thermal drift sensitivity than the last. The proposal of this work is to show a applied to a FORG technique that simplifies the signal treatment, employing all digital setup, resulting in a maximally flat scale factor. In this investigation are presented over the simulations results, employing the modified digital FM spectrometry techniques by decimation and interpolation techniques over a ring resonator that pursuit a 10 meters SM-PM lenght fiber coil and 10 centimeters of diameter, with a 1550 nanometers laser source. The advantages of these techniques are to simplify the electronic circuitry, offering an upgrade facility, using only one DSP (Digital Signal Processor), realizing all needed functions. The investigation of this method is based in a optical field switching scheme and digital frequency domain spectrometry.