Binary Addressable Optical Multiplexing Waveguides via Electrochromic Switching

Abstract

Photonic circuits attract much attention as promising candidates to overcome the drawbacks of their electronic counterparts. By utilizing the broad bandwidth and low energy consumption of optical communication, hybrid circuits can provide a comprehensive platform for the era beyond Moore's law. In particular, parallel matrix operations, the heavy lifting behind neural networks, remain challenging for traditional electronics due to high heat dissipation. To enable these parallel computations optically, (de‐)multiplexing is crucial to address the different channels. Previously this has been accomplished with complex spectral or time encodings in wave division or time division methods. However, herein, a simple method to address parallel optical channels exclusively with 2‐bit signals is presented. By using PEDOT:PSS as electrochromic material for intensity modulation, light transmission or absorption is controlled by oxidation and reduction with an electrolyte. Y‐branch structures are used to design the multiplexing layout and to assign the 2‐bit states to the channels. This binary addressable optical multiplexer, therefore, combines optical communication with electronic signals into a hybrid circuit.