Study on Spectral Selective Manipulation Characteristics of Surface Multilevel Micro-Nano Structures by FDTD Simulation.

Xiangjing Guo,Haiying Song,Shengwang Tan,Shibing Liu,Bairui Du

doi:10.3390/ijms23052774

Xiangjing Guo, Haiying Song + Show 3 more

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https://doi.org/10.3390/ijms23052774

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Abstract

The optical filter based on the micro–nano structure on the material surface is an important optical device, which is widely used in many fields. The filter is fabricated on the substrate with different shapes and sizes of micro–nano array structure, and the wavelength selectivity is realized by adjusting the processing parameters. In this paper, the finite-difference time-domain (FDTD) method is used to simulate the spectral properties of periodic array structures on the Au surface, and the spectral response characteristics of different surface structural parameters to the incident light are obtained. The simulation results show that the periodic pore array has a directional modulation function on the reflectivity and transmittance of the material surface. In the same circular aperture array structure, the wavelength selection ability is proportional to the interval distance of the array period, but the transmission peak linewidth decreases with the increase of the interval distance. The structural spectrum of the cylindrical array is closely related to the structural period. The period of the array structure increases in proportion, the center wavelengths of the reflection and transmission peak of the spectrum are red-shifted. When the height of the array structure increases proportionally, the positions of the center wavelengths of the reflection and transmission peak remain almost unchanged. When the period of the array structure increases, the center wavelength of the reflection and transmission peaks appear red-shifted, and the line width is also narrowed. For the periodic ring array structure, as the inner diameter increases, the reflection peak is significantly red-shifted, and the smaller the ring width, the faster the red-shift of the reflection peak with the wavelength. By controlling the ratio of inner diameter-to-outer diameter, the spectral characteristics of the structured surface can be effectively controlled. These simulation results provide a basis for the preparation of optical filters in the future and a new idea for the study of micro–nano characteristic structures on the surface of materials.

Highlights

The optical filter is a typical optical device, which can realize the selection of optical wavelength by making the light at a specific wavelength penetrate or cut off [1–4]
Since the transmission peak in the transmission spectrum appears at the wavelength of 0.675 μm, the electric field distribution at different positions at this wavelength is mainly discussed
This paper proposed substrate-micro/nano structures integrated characteristic structural materials, and simulated the change of reflection spectral characteristics and selective spectral length caused by different geometric parameters by finite difference time domain method

Summary

Introduction

The optical filter is a typical optical device, which can realize the selection of optical wavelength by making the light at a specific wavelength penetrate or cut off [1–4]. With the development of micro–nano processing technology, optical filters based on metal micro–nano structures have been widely used, and have great potential in solar thermal photovoltaic systems, biological sensors, thermal radiators, and other fields [5–7]. The super-transmission spectrum can be effectively controlled by adjusting the geometric shapes of nano-apertures, such as circular, rectangular, and sandwich structures, due to the incident excitation light-generating resonant coupling of surface plasmons at the microstructure array. A series of microstructures constructed are proposed by scientists, such as nanowires, nanoparticles, nano-cones, one-dimensional grating structure, two-dimensional photonic crystals, micro–nano waveguides, which are widely used in the research fields of electronics, microelectronic mechanical systems, and solar photovoltaic devices [14–22]

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