Phase sensitive sensor on Tamm plasmon devices

Syuan-Guei Huang,Kuo-Ping Chen,Shie-Chang Jeng

doi:10.1364/ome.7.001267

Abstract

This work proposes a refractive index sensing concept of a Tamm plasmon (TP) device by using spectroscopic ellipsometry and phase detection. A TP device is generally composed of a 1-D photonic crystal (PC) with a metallic film on top of it. We found that the sensing performance can be improved by adjusting the parameters of the incident angle of polarized light, the top layer thickness, and the central wavelength of the PC. By designing proper parameters, it was found that the change of the phase difference of p-polarized and s-polarized lights, δ∆, can reach 34° when the ambient environment is changed from air (n = 1.00028) to carbon dioxide (n = 1.00045). A sensitivity of δ∆/δn ~2 × 105 °/RIU can then be obtained for the proposed TP device.

Highlights

Plasmonics has been a rapidly developing topic in photonics
A Tamm plasmon (TP) device is generally composed of a 1-D photonic crystal (PC) with a metallic film on top of it
We found that the sensing performance can be improved by adjusting the parameters of the incident angle of polarized light, the top layer thickness, and the central wavelength of the PC

Summary

Introduction

Plasmonics has been a rapidly developing topic in photonics It has provided many applications in biophotonics and chemistry [1,2]. Tamm plasmon (TP), formed by a high refractive index/low refractive index alternate-layered photonic crystal (PC) coated with a metallic film, can be excited by both the TE and TM polarization without using additional dispersion optics [4], it is more convenient for practical applications. The presence of air layers in their proposed TP structure, an air/dielectric alternate-layered PC, increases the refractive index contrast of the PC and greatly enhances the sensor sensitivity by measuring the shift of resonance wavelength with the change of ambient refractive index. The approach of spectroscopic ellipsometry (SE) was applied to measure the phase difference of p-polarized and s-polarized lights with the ambient refractive index for a TP device.

Structure design and analysis

Results and discussion

Conclusions