Manipulating ITO-based controllable phase shifters for designing a compact, high bandwidth optical mode selective router integrated on silicon-on-insulator waveguides

Abstract

Recently, Indium Tin Oxide, a highly transparent, well conductive, and CMOS-compatible material, has been paying strong attention to the thermo-optic controlled silicon photonics industry because it allows a miniature of the gap between the core silicon and the metallic heater, thus enabling reducing the electric power consumption and enhancing the switching speed. In this article, we propose an ultralow loss and small-size ITO microheater for the phase shift tuning. The designated microheater is manipulated to realize a numerical design of a compact and high bandwidth three-mode selective router. Simulation results illustrate the 3-dB bandwidth for the three-mode selective router as much as 100-nm and 40-nm during crosstalk under -25 dB, respectively. Besides, the designed device attains relatively large fabrication tolerances corresponding to width and height tolerances of ±50 nm and ±5 nm. In addition, the proposed devices consumed less than 90 mW total power consumption and took a fast switching time below 8 μs. Moreover, the design structure of the suggested mode selective router can be integrated into an estimated compact footprint of 8 μmÍ2160 μm. Such excellent performances demonstrate the attractive potential of ITO as low-loss thermo-optic phase shifters and open an alternative way for enabling ultrafast and high-speed mode division multiplexing systems and very large-scale photonic integrated circuits.