On-Chip Multi-Dimensional 1 × 4 Selective Switch With Simultaneous Mode-/Polarization-/Wavelength-Division Multiplexing
Xiaoping Cao, Shuang Zheng, Nan Zhou, Jieying Zhang, Jian Wang
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×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 1×4 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.