Electromechanically Rotatable Cross-Shaped Mid-IR Metamaterial

Abstract

We present an electromechanically rotatable infrared (IR) cross-shaped metamaterial (CSM) in the mid-IR wavelength range. The CSM configuration is composed of double gold layers with cross-shaped nanostructures. To investigate the fano-resonance within CSM nanostructures, the aspect ratios and length ratios of CSM are compared and discussed. The electromagnetic responses exhibit the characteristics of large tuning range, tunable broad and narrow bandwidths. By properly tailoring the aspect ratio of CSM, the resonance can be tuned with bidirectional tuning in the range of 650 nm. CSM with different length ratios exhibit narrowband resonances around the wavelength of 4.6 μm and broadband resonances in the wavelength range of 5.0 μm to 6.5 μm. These characteristics of CSM with different aspect ratios and length ratios could be potentially used in IR narrowband and broadband filter. To further increase the flexibility of proposed electromechanically rotatable CSM, an actively tunable narrowband and broadband filter in the mid-IR wavelength range is performed. This study provides a unique approach to realizing an IR filter, with high flexibility.

Tunable Infrared Metamaterial Emitter for Gas Sensing Application

“…They are widely studied to realize thermal emitters and are perfect absorbers for energy harvesting, medical imaging, and high-sensitivity sensing applications [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. By tailoring the geometrical dimensions, metamaterials can be designed to span broad operating wavelengths, including visible [ 31 , 32 , 33 ], IR [ 34 , 35 , 36 , 37 , 38 , 39 ], terahertz [ 40 , 41 , 42 , 43 , 44 ], and microwave light [ 45 , 46 ]. To provide metamaterials with more flexibility, there are many techniques proposed for tuning mechanisms using MEMS technology [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]: liquid crystal [ 55 ], photo-excited [ 56 ], phase-change materials [ 57 , 58 ], thermal annealing [ …”

Tunable Perfect Meta‐Absorber with High‐Sensitive Polarization Characteristic

“…In view of tunable metamaterial absorber is indispensable to perform the controllable modulator, flexible photovoltaic device, and tunable sensor, [ 26–29 ] it becomes a research hot topic recently. The tuning mechanisms of tunable metamaterial absorbers are included but not limited to the uses of a phase change material, [ 30 ] electrical control, [ 31,32 ] liquid crystal, [ 33,34 ] and micro‐electro‐mechanical system (MEMS) technique [ 35–42 ] to dynamically tune the absorption resonance. To actively achieve the control of absorption spectrum, these tuning methods are limited to only certain electromagnetic property, which is either resonant frequency or resonant intensity.…”

Polarization-Sensitive Metamaterials with Tunable Multi-Resonance in the Terahertz Frequency Range

“…There has been much research presenting and demonstrating the use of diversified SRR designs [8][9][10][11][12][13], either symmetrically or asymmetrically, such as cross-shaped SRR [9], V-shaped SRR [10,11], spiral-shaped SRR [12], and multiple SRRs [13]. In view of these extraordinary optical properties of SRR-based metamaterials, there have been extensive studies reported in the different frequency ranges, from microwave, terahertz (THz), and infrared to visible spectra [14][15][16][17][18][19].…”