Electronic-photonic circuit crossings

TL;DR

This paper introduces a novel single-layer electronic-photonic circuit crossing with high optical transmission, enabling integrated opto-electro-mechanical functionalities in photonic circuits, addressing key integration challenges.

Contribution

It presents a topology-optimized design for a single-layer circuit crossing with high optical transmission and demonstrates a monolithic silicon nanoelectromechanical switch integrating photons, electrons, and mechanical motions.

Findings

Achieved up to 99.8% optical transmission across a 20 nm trench.

Measured 92.9% average transmission over 100 nm bandwidth.

Demonstrated a monolithic silicon nanoelectromechanical add-drop switch.

Abstract

Electrical control of light in integrated photonics is central to a wide range of research and applications. It is conventionally achieved with thermo-optic tuning, but this suffers from high energy consumption and crosstalk. Nanoelectromechanical photonics could resolve these issues, but integrating this technology with conventional multilayer metal architectures is challenging, and conventional approaches do not allow crossings of electrical wires and photonic waveguides. Here, we use topology optimization to devise a single-layer electronic-photonic circuit crossing with up to 99.8 % optical transmission across a 20 nm electrical isolation trench. We focus our experiments on 100 nm trenches and measure an average transmission of 92.9 % over a 100 nm bandwidth, in excellent agreement with theory. We use these concepts to demonstrate a monolithic silicon nanoelectromechanical add-drop switch in which the flow of photons, electrons, and mechanical motions are fully integrated within the same layer. Our work addresses an important challenge in incorporating opto-electro-mechanical topologies into photonic integrated circuits and may lead to new functionalities in nano-opto-electro-mechanical systems, optomechanics, and integrated quantum photonics.