Sensitivity limit of a coupled-resonator optical waveguide gyroscope with separate input/output coupling

This paper studies a coupled-resonator optical waveguide (CROW) gyroscope consisting of identical coupled rings and coupling ratios except the input and output couplers have a different coupling ratio. Under certain circumstances this gyroscope is found to be more sensitive than the same gyroscope with all equal coupling ratios. However, its maximum achievable sensitivity does not exceed that of an optimized single-ring resonator gyroscope with the same ring radius and loss. This conclusion applies whether the CROW gyroscope is folded or unfolded, whether it utilizes one or two input/output waveguides, and regardless of the number of rings and waveguide loss. (C) 2015 Optical Society of America