An Optical Sensor Designed From Cascaded Anti-Resonant Reflection Waveguide and Fiber Ring-Shaped Structure for Simultaneous Measurement of Refractive Index and Temperature

Jiewen Zheng,Bo Liu,Jianxin Ren,Rahat Ullah,Yaya Mao,Tutao Wang,Lilong Zhao

doi:10.1109/jphot.2022.3144156

Abstract

A novel optical fiber sensor based on cascade anti-resonant reflection waveguide (ARRW) and fiber ring-shaped structure (FRSS) is proposed and experimentally demonstrated for simultaneous measurement of refractive index (RI) and temperature. The sensor is very simply fabricated by splicing ARRW and FRSS based on Mach-Zehnder interference (MZI). The FRSS interference dip is sensitive to external RI and temperature changes, whereas the ARRW structure's loss dip is only sensitive to external temperature. As a result, this sensor can be used to measure both RI and temperature simultaneously. The sensor's maximum RI sensitivity is 108.61 nm/RIU and its maximum temperature sensitivity is 19 pm/ °C in the experiment. This sensor is a good choice when it is necessary to measure RI and temperature at the same time due to its compact size, high sensitivity, low cost, and good stability.

Highlights

D UE to their unique advantages such as strong antielectromagnetic interference ability, high sensitivity, good insulation, ease of manufacture, and corrosion resistance, optical fiber sensors have received a lot of attention in recent years
Where ΔT and ΔN respectively represent the changes of temperature and refractive index (RI), kT1 and kN1 respectively represent the sensitivity of balloon dip to temperature and RI, kT2 is the sensitivity of antiresonant reflection waveguide (ARRW) dip to temperature
From the above experimental results, the ARRW dip is not sensitive to RI, which is consistent with the theoretical analysis

Summary

INTRODUCTION

D UE to their unique advantages such as strong antielectromagnetic interference ability, high sensitivity, good insulation, ease of manufacture, and corrosion resistance, optical fiber sensors have received a lot of attention in recent years. Simultaneous measurement of RI and temperature are of crucial importance for many biochemical and physical practical applications Fiber gratings, such as (LPFG) and fiber Bragg gratings (FBG), are commonly used to measure RI and temperature simultaneously in a cascade with other sensing structures due to their temperature-sensitive and RI insensitive characteristics. The ARRW structure [18]–[20] has the advantages of easy manufacture, compact structure, and low cost, and its working mechanism is different from that of MZI It shows great application potential in measuring RI and temperature simultaneously after cascading with other MZI structures. The sensor has the ability to compensate for the temperature effect in the case of RI-based sensing and can be widely used in the fields of environmental, biological, and chemical sciences

FABRICATION AND PRINCIPLE

For Analyzing the RI Response

For Analyzing the Temperature Response

CONCLUSION