Optical bistability on a silicon chip

Abstract

We demonstrate, for the first time to our knowledge, optical bistability on a highly integrated silicon device, using a $5‐\mathit{\mu }\mathrm{m}$-radius ring resonator. The strong light-confinement nature of the resonator induces nonlinear optical response with low pump power. We show that the optical bistability allows all-optical functionalities, such as switching and memory with microsecond time response and a modulation depth of 10 dB, driven by pump power as low as $45 \mathit{\mu }\mathrm{W}$. Silicon optical bistability relies on a fast thermal nonlinear optical effect presenting a 500-kHz modulation bandwidth.