Intensity Modulated Gas RI Sensor Based on Inornate Antiresonant Hollow-Core Fiber With Ultrahigh Sensitivity

Maoxiang Hou,Yun Chen,Jianguo Ma,Xin Chen,Neng Wang

doi:10.1109/access.2021.3064600

Abstract

A gas refractive index (RI) sensor based on an inornate antiresonant hollow-core fiber (HCF) was theoretically analyzed and experimentally demonstrated. The transmission spectra evolution of the proposed sensor and the resonance intensity variations to the surrounding gas RI were simulated. Theoretical analysis found that the intensity sensitivity of inornate HCF is higher than that of coated HCF. In the experiment, a sensor with a 5 mm-long HCF provided exceptional sensitivity-as high as 2236.1 dB/RIU. The sensitivity was enhanced by improving the resonance intensity of the inornate HCF, which could be further improved by increasing the HCF length. In addition, temperature sensing was performed to resolve the temperature cross-sensitivity issue using a wavelength interrogation method. The proposed RI sensor exhibited the advantages of easily manufactured and with ultrahigh sensitivity.

Highlights

The refractive index (RI) of a gas is seen as a gauge of information such as its concentration, type, and optical properties, which are of great significance in the petrochemical industry [1], gas lasing systems [2] and environmental monitoring [3]
We demonstrate a gas RI sensor using an AR-based inornate hollow-core fiber (HCF), which can achieve an ultrahigh sensitivity when interrogating the intensity of the transmission resonance dips
It is a sensible way to use the inornate HCF as a gas RI sensor to overcome the temperature cross-sensitivity problem. This inornate HCF-based gas RI sensor had a maximum sensitivity of 2,236.1 dB/RIU for an HCF of length 5 mm, the sensitivity could continue to be improved by increasing the length of the HCF

Summary

INTRODUCTION

The refractive index (RI) of a gas is seen as a gauge of information such as its concentration, type, and optical properties, which are of great significance in the petrochemical industry [1], gas lasing systems [2] and environmental monitoring [3]. The complicated configuration and fragile structure of the above sensors limit their practical implementation and their potential for mass production In this regard, reliable gas RI sensors with high sensitivity, accuracy, and costeffectiveness are in great demand in real-world applications. M. Hou et al.: Intensity Modulated Gas RI Sensor Based on Inornate Antiresonant HCF With Ultrahigh Sensitivity advantages in the sensing fields [15]. The HCF can be preprocessed through a femtosecond laser drilling hole to detect the outside air pressure [24], [25] These sensors require elaborate processes, such as film thickness control and, femtosecond micromachining, which seriously restrict mass production and application. We demonstrate a gas RI sensor using an AR-based inornate HCF, which can achieve an ultrahigh sensitivity when interrogating the intensity of the transmission resonance dips. The proposed sensor exhibited a simple production process, and making it beneficial to large-scale manufacturing with great potential for chemical applications

SENSING PRINCIPLE AND SIMULATION RESULTS

CONCLUSION