Ultra-sensitive chip scale Sagnac gyroscope based on periodically modulated coupling of a coupled resonator optical waveguide

Abstract

We analyze the sensitivity to inertial rotations Ω of a micron scale integrated gyroscope consisting of a coupled resonator optical waveguide (CROW). We show here that by periodic modulation of the evanescent coupling between resonators, the sensitivity to rotations can be enhanced by a factor up to 10(9) in comparison to a conventional CROW with uniform coupling between resonators. Moreover, the overall shape of the transmission through this CROW superlattice is qualitatively changed resulting in a single sharp transmission resonance located at Ω = 0s-1 instead of a broad transmission band. The modulated coupling therefore allows the CROW gyroscope to operate without phase biasing and with sensitivities suitable for inertial navigation even with the inclusion of resonator losses.

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

“…Gyroscopes have another very important parameter, which is the minimum detectable angular velocity Ω min , or the resolution. light source and photo detector as mentioned in reference [13] ( ) , which is less than 0.001°/h. In Fig.…”

“…Thus, it looks like that the effective area of our gyroscope is not very high, which will lead to a lower precision. Interestingly, after modulated the coupling coefficient between resonators or their circumferences, the effective area of our gyroscope exponentially increases [13][14][15]. Here, the modulation of the coupling coefficient means to changing the coupling coefficient symmetrically and alternately from the center to the edge of the resonator array.…”

“…Furthermore, we cannot get this advantage from the ring laser gyroscope (RLG) and fiber optical gyroscope (FOG). What's more, the minimum detectable angular velocity of inertial navigation should be less than 0.01°/h [10,12], and the CROW gyroscope can reach 0.001°/h [13]. This sensitivity is higher than the micro electro mechanical system (MEMS) gyroscopes, which have a widely range of application in smart phones.…”

Recent advances in miniaturized optical gyroscopes

“…In [82,83] the impact of chirped CROW on the performance of a gyro is analyzed. In [82] a comparison between the spectral response of an array of identical resonators and an array of resonators that have different dimensions is reported.…”

“…Moreover, when coupling coefficients between resonators are chirped, instead of their length, the spectral response exhibits a sharper transmission resonance. This would allow the design of a phase sensitive gyro with a resolution of 0.002 • /h and a footprint area of 0.16 mm [83].…”