Photonic Crystal Fiber SPR Liquid Sensor Based on Elliptical Detective Channel.

Xin Yan,Shuguang Li,Yao Wang,Tonglei Cheng

doi:10.3390/mi12040408

Abstract

This paper proposes a Photonic Crystal Fiber (PCF) refractive index sensor model based on the surface plasmon resonance effect. The proposed PCF model also uses the full vector finite element method to transfer the structure under the anisotropic Perfect Matching Layer (PML) boundary condition. Numerical calculations were carried out on the sensor characteristics. The calculation results show that the elliptical air hole on the left side of the PCF core is coated with a gold-nano film which serves as a Surface Plasmon Resonance (SPR) sensing channel to detect the refractive index of liquid materials. Compared with other structures, the resonant peak generated by the excited SPR effect from the elliptical sensing channel has a high sensitivity to the change of the refractive index of the liquid to be measured. With the help of this attribute, it is relatively easy to adjust the sensitivity. The refractive index range of this structure is within 1.43–1.49 and the sensitivity is up to 12,719.97 nm·RIU−1. The linearity is good; R2 = 0.99927, which is very suitable for liquid sensing.

Highlights

This paper proposes a Photonic Crystal Fiber (PCF) refractive index sensor model based on the surface plasmon resonance effect
Comparing these two photonic crystal fibers, the Total Internal Reflection Photonic Crystal Fiber (TIR-PCF) is simpler in principle and structure, and it is more suitable for optical fiber sensing
This paper proposes a PCF refractive index sensor based on the Surface Plasmon Resonance (SPR) effect which introduces an asymmetric cladding structure and an elliptical detection channel

Summary

Introduction

Photonic Crystal Fiber (PCF), when comparing it with the traditional fiber, shows more excellent optical characteristics due to its unique structure, such as non-stop single mode [1,2,3,4], low loss, high-nonlinearity [5,6], high-birefringence [7] and controllable dispersion [8], and large mode field area. In 2016, Rahul Kumar Gangwar et al proposed a surface plasmon resonance sensor based on D-type photonic crystal fiber for refractive index sensing [24]. This paper proposes a PCF refractive index sensor based on the SPR effect which introduces an asymmetric cladding structure and an elliptical detection channel. This method widens the dynamic detection range between 1.43–1.49 and a sensitivity of up to 12,719.97 nm·RIU−1 , with good linearity which is suitable for liquid sensing with the high refractive index

Structural and Theoretical Modeling

Simulation Results and Analysis

Confinement

Conclusions