Silicon photonics efficient fiber coupler based on a metastructure with a minimum feature size of 150 nm.

We propose a silicon photonics fiber coupler consisting of a metastructure containing a through-hole array and a partially etched grating to obtain high efficiency. Using an evolution optimization algorithm, we optimized 121 structural parameters and achieved a minimum feature size of 150 nm, which greatly simplifies the fabrication using wafer-scale foundry services. We designed two structures, one achieving an 86% coupling efficiency into a single fiber, and the other exhibiting a full flat spectrum in the C band.

On-chip bacterial foraging training in silicon photonic circuits for projection-enabled nonlinear classification.

On-chip training remains a challenging issue for photonic devices to implement machine learning algorithms. Most demonstrations only implement inference in photonics for offline-trained neural network models. On the other hand, artificial neural networks are one of the most deployed algorithms, while other machine learning algorithms such as supporting vector machine (SVM) remain unexplored in photonics.

Arbitrary reconfiguration of universal silicon photonic circuits by bacteria foraging algorithm to achieve reconfigurable photonic digital-to-analog conversion.

Reconfigurable/reprogrammable universal silicon photonic circuits represent a paradigm shift in designing photonic devices. However, it is very challenging to perform adaptive arbitrary reconfiguration when the high-dimensional solution of phase distribution cannot be explicitly determined, especially when there are random initial phase errors, which hinder the implementation of novel potential functions in universal circuits. This work presents an arbitrary black-box reconfiguration for universal circuits with random phase errors by a bacteria-foraging algorithm and unlocks a novel function of arbitrary-port-and-arbitrary-bit-resolution reconfigurable 6-bit photonic digital-to-analog conversion.

Photonic crystal directional coupler switch with small switching length and wide bandwidth.

A directional coupler switch structure capable of short switching length and wide bandwidth is proposed. The switching length and bandwidth have a trade-off relationship in conventional directional coupler switches. Dispersion curves that avoid this trade-off are derived, and a two-dimensional photonic crystal structure that achieves these dispersion curves is presented.