A Reconfigurable 4-λ × 25-Gb/s/λ Silicon Ring-Resonator-Based WDM Receiver with Fast Wavelength Calibration

We present a reconfigurable $4-\lambda \times 25-\text{Gb} / \text{s} / \lambda$ Si ring-resonator-based WDM receiver and, using it, demonstrate a new wavelength calibration technique that provides ring resonators with desired resonance wavelengths and maintains them against external temperature variation.