Active microring based tunable optical power splitters

In this paper we propose a set of novel tunable optical power splitters based on active microring resonators. They work by operating ring resonators in the transient zone between full resonance and off-resonance states for a specific wavelength. We can achieve different split ratios by either varying the bias voltage, or by selectively enabling a given resonator with a specific split ratio among an array of ring resonators. We take 500 ps to tune the resonator, which is at least 10× better that competing designs. Its split ratio varies from 0.4 to 1.8 for an applied voltage range of 0-5 V.