Multi-Stage Wavelength Locking in a $4 \times 4$ Silicon Electro-Optic Switch Based on Dual-Ring Resonators

We experimentally demonstrate a multi-stage wavelength locking scheme based on saddle point searching in a dual-ring based $4\times 4$ electro-optic switch. Three-stage switching elements can be aligned to the signal wavelength with initial $\leq 2-nm$ wavelength misalignments.