Analytical Study of Optical Bi-Stability of a Single-Bus Resonator Based on InGaAs Micro-Ring Array

In this paper, for the first time to our knowledge, we investigate the optical bi-stability in a compact parallel array of micro- ring resonators with 5μm radius, induced by optical nonlinearity. Due to the nature of perfect light confinement, resonance and accumulation process in a ring resonator, optical nonlinear effects, even at small optical power of a few milliwatts in this structure are observable. Different optical applications such as: all-optical switching, memory, logic gates and modulators, due to optical bi-stability in a ring resonator are possible. By using of compound semiconductors, instead of silicon that have weakly nonlinear optical properties, we improve the performance of ring-resonator based devices. Also by using of a polymer cladding layer with negative thermo-optic coefficient, we have eliminate the temperature created nonlinearity which is a very slow process, so the switching speed of a few MHz increases to several tens of GHz. With plotting the transfer function of the resonator, a hysteresis loop in a few milliwatts is observed, that by using of ring resonator array, although the bandwidth is reduced, but the width of the hysteresis loop and resolution between both steady state increases.