Dissipative sensing with low detection limit in a self-interference microring resonator

A dissipative sensing scheme based on a self-interference microring resonator (SIMRR), which is robust against lasing and microcavity frequency noise in the detecting system with a low noise level, is systematically investigated. The dependence of the performance of an SIMRR sensor in dispersive and dissipative sensing schemes on the physical structural parameters, e.g., the waveguide loss coefficient, the power coupling coefficient, the microring radius, and the initial sensing arm waveguide length in the SIMRR sensor, is studied. Based on the Cramer–Rao lower bound for parameter estimation, the detection limits of dispersive and dissipative sensing are theoretically and numerically analyzed, which demonstrate that the dissipative approach is immune from the frequency noises with a low noise level. The results show that the detection limit of dissipative sensing has great potential to achieve better performance than that of dispersive sensing for a practical commercial tunable laser scanning system.