Design of a plasmonic-organic hybrid slot waveguide integrated with a bowtie-antenna for terahertz wave detection

TL;DR

This paper introduces a novel plasmonic-organic hybrid waveguide with a bowtie antenna for terahertz detection, enabling broadband EM wave sensing from 1 GHz to 10 THz with high sensitivity and minimal field disturbance.

Contribution

The work presents the first POH device capable of detecting terahertz waves, covering a wider spectrum with improved design for ultra-small RC constant and enhanced electric field interaction.

Findings

Device can sense EM waves up to 10 THz

Design achieves ultra-small RC constant and strong field enhancement

First POH device for terahertz wave detection

Abstract

Electromagnetic (EM) wave detection over a large spectrum has recently attracted significant amount of attention. Traditional electronic EM wave sensors use large metallic probes which distort the field to be measured and also have strict limitations on the detectable RF bandwidth. To address these problems, integrated photonic EM wave sensors have been developed to provide high sensitivity and broad bandwidth. Previously we demonstrated a compact, broadband, and sensitive integrated photonic EM wave sensor, consisting of an organic electro-optic (EO) polymer refilled silicon slot photonic crystal waveguide (PCW) modulator integrated with a gold bowtie antenna, to detect the X band of the electromagnetic spectrum. However, due to the relative large RC constant of the silicon PCW, such EM wave sensors can only work up to tens of GHz. In this work, we present a detailed design and discussion of a new generation of EM wave sensors based on EO polymer refilled plasmonic slot waveguides in conjunction with bowtie antennas to cover a wider electromagnetic spectrum from 1 GHz up to 10THz, including the range of microwave, millimeter wave and even terahertz waves. This antenna-coupled plasmonic-organic hybrid (POH) structure is designed to provide an ultra-small RC constant, a large overlap between plasmonic mode and RF field, and strong electric field enhancement, as well as negligible field perturbation. A taper is designed to bridge silicon strip waveguide to plasmonic slot waveguide. Simulation results show that our device can have an EM wave sensing ability up to 10 THz. To the best of our knowledge, this is the first POH device for photonic terahertz wave detection.