Waveguide-type optical passive ring resonator gyro using frequency modulation spectroscopy technique

Abstract

This paper reports the experimental results of silica on a silicon ring resonator in a resonator micro optic gyroscope based on the frequency modulation spectroscopy technique by our research group. The ring resonator is composed of a 4 cm diameter silica waveguide. By testing at λ = 1550 nm, the FSR, FWHM and the depth of resonance are 3122 MHz, 103.07 MHz and 0.8 respectively. By using a polarization controller, the resonance curve under the TM mode can be inhibited. The depth of resonance increased from 0.8 to 0.8913, namely the finesse increase from 30.33 to 33.05. In the experiments, there is an acoustic-optical frequency shifter (AOFS) in each light loop. We lock the lasing frequency at the resonance frequency of the silica waveguide ring resonator for the counterclockwise lightwave; the frequency difference between the driving frequencies of the two AOFS is equivalent to the Sagnac frequency difference caused by gyro rotation. Thus, the gyro output is observed. The slope of the linear fit is about 0.330 mV/(°/s) based on the −900 to 900 kHz equivalent frequency and the gyro dynamic range is ±2.0 × 103 rad/s.

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.…”

Advanced optical devices using Sagnac interference in integrated photonics

“…A PROG based on a silica RR with a diameter of ~4 cm has been demonstrated (Figure 12(b)) [133], where laser frequency modulation spectroscopy technique was used for signal detection in the open-loop operation PROG system. A dynamic range between -2.0 × 10 3 and 2.0 × 10 3 rad/s was experimentally achieved for the PROG, and the slope of the linear fit for the equivalent gyroscope rotation was about 0.330 mV/(deg/s) based on the -900 to 900 kHz equivalent frequency.…”

Suppression Method of Optical Noises in Resonator-Integrated Optic Gyroscopes

“…Twin 90 • polarization-axis-rotated splices in a resonator are proposed for reducing polarization fluctuation-induced noise in RFOG [40]. The TM mode's resonance curve can be inhibited by applying a polarization controller [45] before the line enters the WRR. However, this technology is challenging to implement in RIOG.…”

“…The shot-noise of the photodetector determines the ultimate sensitivity of the RIOG. However, many characteristics, including backscattering [10][11][12][13][14][15][16][17][18][19][20][21][22], back-reflection [23][24][25][26][27][28], nonlinear Kerr effect [29][30][31][32][33][34][35][36][37], polarization fluctuation [38][39][40][41][42][43][44][45][46][47][48][49][50], and laser frequency noise [51][52][53], have negative impacts. These negative impacts degrade the performance of RIOGs and make it worse than the shot-noise limited theoretical sensitivity.…”