Double slot micro ring resonators with inner wall angular gratings as ultra-sensitive biochemical sensors

Cheng, W., Sun, X., Ye, S. , Yuan, B., Xiong, J., Liu, X., Sun, Y., Marsh, J. H. and Hou, L. (2023) Double slot micro ring resonators with inner wall angular gratings as ultra-sensitive biochemical sensors. Optics Express, 31(12), pp. 20034-20048. (doi: 10.1364/OE.483990) (PMID:37381406)

Abstract

We simulate and demonstrate experimentally an inner-wall grating double slot micro ring resonator (IG-DSMRR) with a center slot ring radius of only 6.72 µm based on the silicon-on-insulator platform. This novel photonic-integrated sensor for optical label-free biochemical analysis boosts the measured refractive index (RI) sensitivity in glucose solutions to 563 nm/RIU with the limit of detection value being 3.7 × 10−6 RIU (refractive index units). The concentration sensitivity for sodium chloride solutions can reach 981 pm/%, with a minimum concentration detection limit of 0.02%. Using the combination of DSMRR and IG, the detection range is enlarged significantly to 72.62 nm, three times the free spectral range of conventional slot micro ring resonators. The measured Q-factor is 1.6 × 104, and the straight strip and double slot waveguide transmission losses are 0.9 dB/cm and 20.2 dB/cm, respectively. This IG-DSMRR combines the advantages of a micro ring resonator, slot waveguide, and angular grating and is highly desirable for biochemical sensing in liquids and gases offering an ultra-high sensitivity and ultra-large measurement range. This is the first report of a fabricated and measured double-slot micro ring resonator with an inner sidewall grating structure.

• Item Type: Articles
• Additional Information: Funding: Chinese Ministry of Education collaborative project (B17023); Engineering and Physical Sciences Research Council (EP/R042578/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sun, Yiming and Liu, Professor Xuefeng and Cheng, Weiqing and Marsh, Professor John and Sun, Xiao and Yuan, Bocheng and Hou, Dr Lianping and Ye, Dr Shengwei
• Authors: Cheng, W., Sun, X., Ye, S., Yuan, B., Xiong, J., Liu, X., Sun, Y., Marsh, J. H., and Hou, L.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Optics Express
• Publisher: Optica Publishing Group
• ISSN: 1094-4087
• ISSN (Online): 1094-4087
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Optics Express 31(12):20034-20048
• Publisher Policy: Reproduced under a Creative Commons licence

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
302617		Optically controlled THz phased array antennas	John Marsh	Engineering and Physical Sciences Research Council (EPSRC)	EP/R042578/1	ENG - Electronics & Nanoscale Engineering