Wavelength tuning and stabilization of microring-based filters using silicon in-resonator photoconductive heaters.

We demonstrate that n-doped resistive heaters in silicon waveguides show photoconductive effects with high responsivities. These photoconductive heaters, integrated into microring resonator (MRR)-based filters, were used to automatically tune and stabilize the filter's resonance wavelength to the input laser's wavelength. This is achieved without requiring dedicated defect implantations, additional material depositions, dedicated photodetectors, or optical power tap-outs.

Design and characterization of microring reflectors with a waveguide crossing.

We present a novel design of a wavelength-selective reflector using a microring resonator integrated with a low-loss, low-crosstalk waveguide crossing. Functioning as a reflective notch filter, it can be used for optical communications and for sensor applications. The device is simulated using the transfer-matrix method combined with a two-dimensional finite-difference mode solver and is fabricated by a CMOS-compatible silicon-on-insulator technology.