Resonator Optical Waveguide Gyroscope Research Articles

Analysis of coupled resonator optical waveguide gyroscope based on periodically modulated coupling and circumferences

Based on periodically modulated coupling and circumferences, we developed a new structure for coupled resonator optical waveguide (CROW) gyroscopes. Its sensitivity and resolution were significantly improved. With our new structure, which overcomes the individual limitations of the previous schemes, the sensitivity and resolution of our gyroscope are higher than those with coupling-coefficient modulation alone and circumference modulation alone. The resolution of the gyroscope gradually declines with increasing resonator propagation loss; when the quality factor Q≤2×106, the height of the center resonance peak of the transmission band decreases by more than 90%. Fortunately, this effect can be weakened by increasing the circumference difference. We also numerically analyzed the influence of manufacturing errors on the performance of the gyroscope. We found that the fluctuations of radius have a greater influence than the fluctuations of quality factor.

Effect of Static Disorder on Sensitivity of Coupled Resonator Optical Waveguide Gyroscopes

Coupled resonator optical waveguides (CROWs) have shown theoretical promise as microoptical integrated gyroscopes with sensitivities exceeding comparably sized MEMS gyroscopes. Here, we analyze the effect of static disorder on the rotational sensitivity of a CROW gyroscope. Since CROWs consist of a one-dimensional array of evanescently coupled ring-shaped microresonators, disorder includes random variations of the resonator optical path length and couplings between them resulting from manufacturing errors. We show that the rotational sensitivity of the CROW gyro is relatively stable with respect to variations in the interresonator coupling. By contrast, even modest fluctuations in the resonators' roundtrip optical path length result in substantially lower rotational sensitives. Finally, it is shown that while most random configurations of defects reduce the maximum sensitivity, there are particular configurations for which the rotation sensitivity is significantly higher than that of a CROW without disorder.

Effect of resonator losses on the sensitivity of coupled resonator optical waveguide gyroscopes

Recently there has been a growing interest in microphotonic integrated optical gyroscopes. Here, we analyze the effect of resonator losses on the rotational sensitivity of a coupled resonator optical waveguide (CROW) gyroscope in comparison to a single passive resonator gyroscope of the same size. We show that the CROW gyro offers a superior sensitivity only for very low propagation losses. Moreover, the single ring resonator gyro is found to have a sensitivity that is stable over wide range of resonator losses as well as boasting greater sensitivities than the CROW gyro for propagation losses in the resonators exceeding 10⁻¹ dB/cm.

Effect of input–output coupling on the sensitivity of coupled resonator optical waveguide gyroscopes

We analyze how the evanescent coupling, κe, between the outermost resonators and input/output waveguides of an N-resonator coupled resonator optical waveguide (CROW) gyroscope affects the transmission and sensitivity to rotations. For constant coupling between resonators κ, rotation sensitivities increase as both κe→0 and κe→1 while between these two limits the sensitivity has a minimum. In the weak coupling regime, κe→0, the sensitivity is enhanced by Fabry–Perot oscillations due to the impedance mismatch at the input/output waveguide–CROW interface, while in the strong coupling regime, κe→1, the sensitivity is reduced because the outermost resonators no longer contribute to the CROW transmission. For small N the sensitivity is proportional to N2, while at larger N the sensitivity begins to decrease due to resonator losses.

Chirped area coupled resonator optical waveguide gyroscope

We study the transmission of an optical field through a rotating coupled resonator optical waveguide (CROW) in which the size of the ring resonators changes from one ring to the next. We focus on symmetric integer wavelength chirps of the circumference of the rings relative to the central ring in the array. The transfer matrix method is used to obtain the transmission as a function of the inertial rotation rate Ω resulting from the Sagnac effect. Chirping increases the slope of the oscillations in the transmission as a function of Ω, which can be exploited to further enhance the rotation sensitivity beyond that of a CROW with uniform resonators.