Broadband Nonvolatile Tunable Mode-Order Converter Based on Silicon and Optical Phase Change Materials Hybrid Meta-Structure

Mode-order converter is a fundamental component in multimode optical interconnect, which is in charge of generating different mode-orders in the optical waveguide. In this article, we propose and design a broadband, nonvolatile tunable mode-order converter based on the platform of silicon and optical phase change materials hybrid meta-structure. When TE
₀
mode is input to this device, its functionality can be selectively switched to either keeping original mode-order or converting to another mode-order TE
₁
at the output port. The insertion losses are lower than 0.7 dB and 0.9 dB for the states of TE
₀
in, TE
₀
out and TE
₀
in, TE
₁
out within the wavelength of 1540-1600 nm. The footprint of the device is 22 μm × 3.5 μm. This platform combines the advantages of compact footprint and flexible function endowed by meta-structures, and dynamically tuning ability and nonvolatile characteristic provided by phase change materials. We envision that the proposed platform not only expands the library of the tunable mode-order converter, but also offers an efficient solution to design a series of tunable multimode devices.