Asymmetry Analysis of the Resonance Curve in Resonant Integrated Optical Gyroscopes

Abstract

The Resonant Integrated Optic Gyroscope (RIOG) is a type of high accuracy gyroscope based on the Sagnac effect. A symmetrical resonance curve is very important to the performance of the RIOG. To further investigate and design a RIOG with a waveguide ring resonator, an in-depth research of the asymmetric resonance curve and its influence on the RIOG is fully developed. Four possible optical noises inducing the resonance curve asymmetry are analyzed and their mathematic models are established. These four optical noises are the normal mode effect, the backscattering noise, the backreflection noise and the polarization noise. Any asymmetry of the resonance curve will not only induce a large output bias error into the gyro output, but also seriously decrease the frequency discrimination parameter of the demodulation curve. By using a tunable fiber laser, the high aspect ratio silicon nitride WRR and the silicon dioxide WRR were tested. The experiment measured resonance curves can be well fitted with the theoretical simulation results. The experimental results show that a high aspect ratio silicon nitride waveguide can effectively suppress the polarization noise in the RIOG.

Advanced optical devices using Sagnac interference in integrated photonics

“…By using a trapezoidal phase modulation technique to achieve real-time compensation for the output of the gyroscope, another PROG based on a silica RR with a diameter of ~6 cm has also been reported [134] (Figure 12(c)). The experimental demonstration verified that the deviation induced by noise and short-term drift was significantly reduced after the compensation, yielding a bias stability of ~0.09 deg/s with an integration time of 10 s over 3000 s. Other modulation techniques have also been investigated, either to improve the output from signal detection modules [146][147][148][149], or to reduce the backscattering [145,150,151] and backreflection [145,[152][153][154] noise.…”

“…In contrast to the use of long coiled waveguides as sensing modules in integrated IOGs, the sensing modules in integrated PROGs are implemented by passive resonators, thus allowing for more compact device footprint. Moreover, unlike the IOGs with their sensitivities being restricted by the transmission loss of the long coiled waveguides, the PROGs based on high-Q optical resonators show advantages in achieving high sensitivities [129,132,145]. Figure 12 shows several typical integrated PROGs.…”

Design, fabrication, and characterization of high-Q SION waveguide ring resonators

“…The devices are fabricated and tested. Polarization affects the bias stability of the RIOG, which in turn affects the performance of the RIOG [12] . In order to investigate the polarization characteristics of the SION WRR, the light source is tuned to TE and TM polarization for input, respectively.…”

Research progress of integrated optical gyroscope

“…Therefore, achieving a high Q value optical microcavity is essential for realizing highperformance IROGs. The preparation of the resonant cavity's materials and structures influences the Q value with commonly used materials, including SiO 2 [26][27][28][29][30] , SOI, CaF 2 , polymer and SIN [31][32][33] , and popular resonant cavity structures, including the optical waveguide ring resonator (WRR) and the whispering-gallery mode resonator (WGMR). The research progress on optical resonant cavities is presented in Table 2.…”