On-Chip Multi-Dimensional 1 × 4 Selective Switch With Simultaneous Mode-/Polarization-/Wavelength-Division Multiplexing

Abstract

Optical selective switch based on silicon photonics offers the advantages of compactness, low power consumption and flexible data management in future optical communication networks. Multi-dimensional (mode, polarization, wavelength) multiplexing transmission has become increasingly important for capacity scaling, while the multi-dimensional selective switch is still full of challenges, especially the integrated solution. Here, we propose and demonstrate on-chip multi-dimensional $1\times \text{N}$ selective switch with simultaneous mode-, polarization- and wavelength-division multiplexing. The monolithic integration on a single silicon chip consists of building blocks of cascaded asymmetrical directional couplers for mode/polarization (de)multiplexing, cascaded microring resonators for wavelength (de)multiplexing, and cascaded thermal-tuning Mach-Zehnder interferometers for selective switching. A multi-dimensional $1\times 4$ selective switch chip on silicon platform is fabricated for proof-of-concept demonstration of simultaneous mode, polarization and wavelength selective switching. The inter-mode/inter-polarization crosstalk and intra-mode/inter-port crosstalk are characterized in the experiment, showing favorable performance with worst crosstalk values of −15.6 and −25.38 dB, respectively. The demonstrations may open up new perspectives for on-chip solutions to multi-dimensional optical signal processing for superior capacity scalable optical communication systems.