Measurement of complex optical susceptibility for individual carbon nanotubes by elliptically polarized light excitation

Fengrui Yao,Jin Zhang,Jianlin Zhao,Fajun Xiao,Cheng Chen,Zhipei Sun,Feng Wang,Peng Gao,Qiuchen Zhao,Kaihui Liu,Can Liu,Xuedong Bai,Jiaming Li,Muhong Wu,Dapeng Yu,Shigeo Maruyama,Enge Wang,Shuchen Zhang

doi:10.1038/s41467-018-05932-9

Abstract

The complex optical susceptibility is the most fundamental parameter characterizing light-matter interactions and determining optical applications in any material. In one-dimensional (1D) materials, all conventional techniques to measure the complex susceptibility become invalid. Here we report a methodology to measure the complex optical susceptibility of individual 1D materials by an elliptical-polarization-based optical homodyne detection. This method is based on the accurate manipulation of interference between incident left- (right-) handed elliptically polarized light and the scattering light, which results in the opposite (same) contribution of the real and imaginary susceptibility in two sets of spectra. We successfully demonstrate its application in determining complex susceptibility of individual chirality-defined carbon nanotubes in a broad optical spectral range (1.6–2.7 eV) and under different environments (suspended and in device). This full characterization of the complex optical responses should accelerate applications of various 1D nanomaterials in future photonic, optoelectronic, photovoltaic, and bio-imaging devices.

Highlights

The complex optical susceptibility is the most fundamental parameter characterizing lightmatter interactions and determining optical applications in any material
Carbon nanotubes, a 1D material from rolled-up graphene, have shown fascinating optical properties, e.g., quantized optical transitions[1,2,3], strong many-body interactions[4,5,6,7,8,9] and efficient photon-electron generation[10], enabling diverse applications ranging from photonics[11,12,13,14], optoelectronics[15,16,17], and photovoltaics[18] to bio-imaging[19]
One way to circumvent this difficulty is to measure the absorption of 1D materials, which is proportional to the imaginary part susceptibility (χ2)

Summary

Introduction

The complex optical susceptibility is the most fundamental parameter characterizing lightmatter interactions and determining optical applications in any material. We successfully demonstrate its application in determining complex susceptibility of individual chirality-defined carbon nanotubes in a broad optical spectral range (1.6–2.7 eV) and under different environments (suspended and in device). This full characterization of the complex optical responses should accelerate applications of various 1D nanomaterials in future photonic, optoelectronic, photovoltaic, and bio-imaging devices. We develop a methodology to measure the complex optical susceptibility for individual carbon nanotubes by an elliptical-polarization-based optical homodyne detection. Our results can open up exciting opportunities in characterizing a variety of 1D nanomaterials, including graphene nanoribbon, nanowires, and other nano-biomaterials, facilitating their accurate material design and applications in future photonic, optoelectronic, photovoltaic, and bio-imaging devices

Methods

Results

Conclusion