Simultaneous four-channel thermal adaptation of polarization insensitive silicon photonics WDM receiver.

We propose a novel approach to demonstrate simultaneous multi-wavelength locking during temperature changes in a silicon photonic polarization insensitive microring-based wavelength division multiplexing (WDM) receiver. The DC component of a single monitoring photodetector at the through port of the microring filter array is exploited as a feedback signal with no additional power consumption. This feedback signal is used in control circuitry to properly tune the microring filters using ohmic heating, thus creating a feedback loop for thermal adaptation.

Ultra-short beam expander with segmented curvature control: the emergence of a semi-lens.

We introduce direct curvature control in designing a segmented beam expander, and explore novel design possibilities for ultra-compact beam expanders. Assisted by the particle swarm optimization algorithm, we search for an optimal curvature-controlled multi-segment taper that maintains width continuity. Counterintuitively, the optimization yields a structure with abrupt width discontinuity and width compression features.

Simultaneous wavelength locking of microring modulator array with a single monitoring signal.

A microring modulator array coupled to a common bus waveguide can be used to construct low power, compact and flexible wavelength-division-multiplexing (WDM) transmitters. However, due to extremely small working bandwidths of the rings, it is challenging to find the right resonant wavelength setting and locking the resonance to an external laser. In the paper, we propose a novel technique enabling simultaneous wavelength locking of a microring modulator array with a single monitor, together with automatically optimizing the wavelength setting.

High-density waveguide superlattices with low crosstalk.

Silicon photonics holds great promise for low-cost large-scale photonic integration. In its future development, integration density will play an ever-increasing role in a way similar to that witnessed in integrated circuits. Waveguides are perhaps the most ubiquitous component in silicon photonics.