A Hollow-Core Photonic-Crystal Fiber-Optic Gyroscope Based on a Parallel Double-Ring Resonator.

Kang Zou,Xiaowu Shu,Yijia Gong,Ran Bi,Heliang Shen,Kan Chen

doi:10.3390/s21248317

Abstract

A novel system structure of resonant fiber optical gyroscope using a parallel double hollow-core photonic crystal fiber ring resonator is proposed, which employs the double closed loop and reciprocal modulation–demodulation technique to solve the problem of the length mismatch between rings. This structure can suppress the residual amplitude modulation noise and laser frequency noise, essentially eliminating the influence of the Rayleigh backscattering noise and dramatically reduce the Kerr-effect-induced drift by three orders of magnitude. Thanks to its excellent noise suppression effect, the sensitivity of this novel system can approach the shot-noise-limited theoretical value of 8.94 × 10−7 rad/s assuming the length of the fiber ring resonator is 10 m.

Highlights

Fiber-Optic Gyroscope Based on aThe resonant fiber optic gyroscope (RFOG) using a high-coherence light source can achieve high precision angular velocity measurement by detecting the resonance frequency difference caused by the Sagnac effect [1]
It has been proposed that the Rayleigh backscattering noise may be reduced by using hollow-core photonic-crystal fiber (HCPCF) since most of the mode travels through air instead of silica, but there were some measurements confirming that the backscattering coefficient for some commercial
For reducing many of the parasitic noises limiting the bias performance of the conventional RFOG with a single ring resonator, we propose a novel system structure of RFOG using a parallel-double HCPCF ring resonator, namely, the PDHC-RFOG, which can effectively solve various problems caused by the parasitic noises

Summary

Introduction

The resonant fiber optic gyroscope (RFOG) using a high-coherence light source can achieve high precision angular velocity measurement by detecting the resonance frequency difference caused by the Sagnac effect [1]. The Kerr-effect-induced drift results from the light intensity difference between the CW and CCW waves circulating in the fiber ring resonator (FRR), which can be diminished by implementation of the light intensity feedback control technique [11,12,13] or adoption of spun fiber [14]. As for the drift caused by temperature-driven polarization instability, other groups have successfully reduced much of this drift by adding dual 90◦ polarization axis rotated splices [15] or adoption of a single-polarization resonator based on a micro-optical polarizing coupler [16]. Applying the double closed loop [23] and reciprocal modulation–demodulation technique [10] to the PDHC-RFOG, it is encouraging that other parasitic performance barriers in the conventional RFOG, such RAM noise and laser frequency noise, can be dramatically reduced

The PDHC-RFOG System

Suppression of the Rayleigh Backscattering Noise by the PDHC-RFOG

Suppression of the Kerr-Effect-Induced Drift by the PDHC-RFOG

Conclusions