Large area multi-channel plasmonic absorber based on the touching triangular dimers fabricated by angle controlled colloidal nanolithography

Herein, based on the finite‐element calculation method, a high‐sensitivity infrared absorption sensor is designed with ZnSe as the substrate, Mo as the waveguide layer and periodic grating, and Ge as the thin film. The absorption performance of the structure is not sensitive to the polarization of the incident light when the transverse‐magnetic light wave is perpendicular to the structure. The thickness of the Ge thin film and the width of the grating column are the main factors for determining its absorption and sensing performance. The optimized structure is sensitive to the refractive index on the grating. Herein, a correspondence between the refractive index change and the position of the peak of the absorbance spectrum is established. When this structure is used as a refractive index sensor, the sensitivity can reach 2300 nm RIU−1 with a high figure of merit of 37.09. In addition, temperature sensing in ethanol shows that the waveguide can quantify the solution temperature by resonance. It is demonstrated in the results that the grating absorber has great potential applications in biomedical sensing.

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“…There are two important parameters to evaluate the refractive index sensor, sensitivity [ 28 ] and FOM. [ 29 ]

S = \frac{Δ λ}{Δ n}

FOM = \frac{S}{FWHM}

where the λ is the wavelength at the resonance peak, and n is the refractive index of the biological solution or gas.…”

Section: Structure and Theorymentioning

confidence: 99%

“…There are two important parameters to evaluate the refractive index sensor, sensitivity [28] and FOM. [29] S…”

Section: Structure and Theorymentioning

confidence: 99%

High‐Sensitivity Thin‐Film Grating Absorbers for Sensing Applications

Sun

Shen

Zheng

et al. 2023

Physica Status Solidi (b)

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“…Compared with singlechannel absorbers, multi-channel optical absorbers have a broader application field, so people have always hoped to achieve multi-channel controllable and high-efficiency absorption in a wide wavelength range. Currently, the multi-channel optical absorbers are mainly based on electromagnetic resonance [5,6], surface plasmon resonance [7,8], and optical Tamm state (OTS) [9]. OTS is a localized interface mode.…”

Section: Introductionmentioning

confidence: 99%

Multi-Channel High-Performance Absorber Based on SiC-Photonic Crystal Heterostructure-SiC Structure

Han

Jiang

et al. 2022

Nanomaterials

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The multi-channel high-efficiency absorber in the mid-infrared band has broad application prospects. Here, we propose an SiC-photonic crystal (PhC) heterostructure-SiC structure to realize the absorber. The absorption characteristics of the structure are studied theoretically. The results show that the structure can achieve high-efficiency multi-channel absorption in the mid-infrared range. The absorption peaks come from the coupling of the dual Tamm phonon polariton (TPhP) mode formed at the interface between the two SiC layers and the photonic crystal, and the optical Tamm state (OTS) mode formed in the PhC heterostructure. By adjusting the thickness of the air dielectric layer and the period of the PhC in the heterostructure, the mode coupling intensity can be regulated; thereby, the position and intensity of the absorption peak can be adjusted. In addition, the absorption peaks of TE and TM polarized light can be controlled by changing the incident angle. Adjusting the incident angle can also control the excitation and intensity of the epsilon-near-zero (ENZ) phonon polariton mode produced by TM polarized light. This kind of light absorber may have potential applications in sensors, filters, modulators, switches, thermal radiators, and so on.

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