scholarly journals Design of Narrow-Band Absorber Based on Symmetric Silicon Grating and Research on Its Sensing Performance

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 553
Author(s):  
Miao Pan ◽  
Huazhu Huang ◽  
Wenzhi Chen ◽  
Shuai Li ◽  
Qinglai Xie ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Incident Light ◽  
Geometric Parameters ◽  
Absorption Peak ◽  
Basic Unit ◽  
Polarization Angle ◽  
Refractive Index Sensitivity ◽  
Absorption Mechanism ◽  
Strong Light ◽  
Surface Plasmon Waves

In this paper, using the surface plasmon and Fabry–Pérot (FP) cavity, the design of a symmetric silicon grating absorber is proposed. The time-domain finite difference method is used for simulation calculations. The basic unit structure is a dielectric grating composed of silicon dioxide, metal and silicon. Through the adjustment of geometric parameters, we have achieved the best of the symmetric silicon grating absorber. A narrowband absorption peak with an absorption rate greater than 99% is generated in the 3000–5000 nm optical band, and the wavelength of the absorption peak is λ = 3750 nm. The physical absorption mechanism is that silicon light generates surface plasmon waves under the interaction with incident light, and the electromagnetic field coupling of surface plasmon waves and light causes surface plasmon resonance, thereby exciting strong light response modulation. We also explore the influence of geometric parameters and polarization angle on the performance of silicon grating absorbers. Finally, we systematically study the refractive index sensitivity of these structures. These structures can be widely used in optical filtering, spectral sensing, gas detection and other fields.

scholarly journals An Asymmetric Silicon Grating Dual-Narrow-Band Perfect Absorber Based on Dielectric-Metal-Dielectric Structure

2021 ◽  
Vol 8 ◽  
Author(s):  
Feng Xu ◽  
Lixia Lin ◽  
Dongwei Wei ◽  
Jing Xu ◽  
Jun Fang
Keyword(s):  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Narrow Band ◽  
Incident Angle ◽  
Incident Light ◽  
Fdtd Method ◽  
Geometric Parameters ◽  
Refractive Index Sensor ◽  
Polarization Angle ◽  
Perfect Absorber

With the exhaustion of world energy, new energy has become the most important content of each country’s development strategy. How to efficiently use solar energy has become a research hotspot in current scientific research. Based on surface plasmon resonance and Fabry-Perot (FP) cavity, this paper proposes a design method of asymmetric silicon grating absorber, and uses finite difference time domain (FDTD) method for simulation calculation. By adjusting the geometric parameters, the asymmetric silicon grating absorber realizes two narrow-band absorption peaks with absorption greater than 99% in the optical wavelength range of 3,000–5,000 nm, and the absorption peak wavelengths are λ1 = 3,780 nm and λ2 = 4,135 nm, respectively. When the electromagnetic wave is incident on the surface of the metamaterial, it will excite the plasmon resonance of the metal to form a surface plasmon (SP) wave. When the SP wave propagates along the x axis, the silicon grating can reflect the SP wave back and forth. When the frequency of the SP wave and the incident light are equal, it will cause horizontal FP coupling resonance, resulting in different resonance wavelengths. This paper also discusses the influence of geometric parameters, incident angle and polarization angle on the performance of silicon grating absorbers. Finally, the sensing performance of the structure as a refractive index sensor is studied. The absorber can be used for various spectral applications such as photon detection, optical filtering and spectral sensing.

Dynamically tunable plasmon-induced transparency effect based on graphene metasurfaces

2021 ◽  
Author(s):  
Shuxian Chen ◽  
Junyi Li ◽  
Zicong Guo ◽  
Li Chen ◽  
Kunhua Wen ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Incident Light ◽  
Polarization Angle ◽  
Refractive Index Sensitivity ◽  
Coupled Mode ◽  
Terahertz Devices ◽  
Index Sensitivity ◽  
Induced Transparency ◽  
Difference Time ◽  
Plasmon Induced Transparency

Abstract Plasmon-induced transparency (PIT) is theoretically explored with a graphene metamaterial using finite-difference time-domain numerical simulations and coupled-mode-theory theoretical analysis. In this work, the proposed structure is consisted of one rectangular cavity and three strips to generate the PIT phenomenon. The PIT window can be regulated dynamically by adjusting the Fermi level of the graphene. Importantly, the modulation depth of the amplitude can reach 90.4%. The refractive index sensitivity of the PIT window is also investigated, and the simulation result shows that a sensitivity of 1.335 THz/RIU is achieved. Additionally, when the polarization angle of the incident light is changed gradually from 0˚ to 90˚, the performances of the structure are greatly affected. Finally, the proposed structure is particularly enlightening for the design of dynamically tuned terahertz devices.

scholarly journals Plasmonics Induced Multifunction Optical Device via Hoof-Shaped Subwavelength Structure

2020 ◽  
Vol 10 (8) ◽  
pp. 2713 ◽  
Author(s):  
Kui Wen ◽  
Zhaojian Zhang ◽  
Xinpeng Jiang ◽  
Jie He ◽  
Junbo Yang
Keyword(s):  
Surface Plasmon ◽  
Near Infrared ◽  
Optical Switch ◽  
Incident Light ◽  
Infrared Range ◽  
Polarization Angle ◽  
Electromagnetic Spectrum ◽  
Optical Device ◽  
Integrated Devices ◽  
Structure Array

The electromagnetic spectrum includes the frequency range (spectrum) of electromagnetic radiation and its corresponding wavelength and energy. Due to the unique properties of different frequency ranges of the electromagnetic spectrum, a series of functional devices working in each frequency rang have been proposed. Here, we propose a periodic subwavelength hoof-shaped structure array, which contains a variety of geometric configurations, including U-shaped and rectangle structures. The results show that the enhanced optical transmission (EOT) effect of the surface plasmon excited by the hoof-shaped structure is highly sensitive to the polarization of the incident light, which leads to the peak’s location shift and the amplitude intensity variety of transmission peaks of U-shaped structure in the case of coupling based on the surface plasmon of rectangle structure. In addition, take advantage of the EOT effect realized in the periodic hoof-shaped structure array, we propose a multifunctional plasmon optical device in the infrared range. By adjusting the polarization angle of the incident light, the functions of the optical splitter in the near-infrared range and the optical switch in the mid-infrared range are realized. Moreover, with the changes of the polarization angle, different proportions of optical intensities split are realized. The device has theoretically confirmed the feasibility of designing multifunctional integrated devices through a hoof-shaped-based metamaterial nanostructure, which provides a broad prospect for the extensive use of multiple physical mechanisms in the future to achieve numerous functions in simple nanostructures.

scholarly journals Novel Two-Dimensional Layered MoSi2Z4 (Z = P, As): New Promising Optoelectronic Materials

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 559
Author(s):  
Hui Yao ◽  
Chao Zhang ◽  
Qiang Wang ◽  
Jianwei Li ◽  
Yunjin Yu ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Incident Light ◽  
Optoelectronic Devices ◽  
Large Family ◽  
Middle Layer ◽  
Optoelectronic Device ◽  
First Principles Calculation ◽  
Polarization Angle ◽  
Two Dimensional ◽  
Conducting Materials

Very recently, two new two-dimensional (2D) layered semi-conducting materials MoSi2N4 and WSi2N4 were successfully synthesized in experiments, and a large family of these two 2D materials, namely MA2Z4, was also predicted theoretically (Science, 369, 670 (2020)). Motivated by this exciting family, in this work, we systematically investigate the mechanical, electronic and optical properties of monolayer and bilayer MoSi2P4 and MoSi2As4 by using the first-principles calculation method. Numerical results indicate that both monolayer and bilayer MoSi2Z4 (Z = P, As) present good structural stability, isotropic mechanical parameters, moderate bandgap, favorable carrier mobilities, remarkable optical absorption, superior photon responsivity and external quantum efficiency. Especially, due to the wave-functions of band edges dominated by d orbital of the middle-layer Mo atoms are screened effectively, the bandgap and optical absorption hardly depend on the number of layers, providing an added convenience in the experimental fabrication of few-layer MoSi2Z4-based electronic and optoelectronic devices. We also build a monolayer MoSi2Z4-based 2D optoelectronic device, and quantitatively evaluate the photocurrent as a function of energy and polarization angle of the incident light. Our investigation verifies the excellent performance of a few-layer MoSi2Z4 and expands their potential application in nanoscale electronic and optoelectronic devices.

EMISSION ENHANCEMENT CHARACTERISTICS OF OXAZINE IN PMMA MATRIX INFLUENCED BY SURFACE PLASMON POLARITON INDUCED ON SINUSOIDAL SILVER GRATING

2012 ◽  
Vol 21 (01) ◽  
pp. 1250013 ◽  
Author(s):  
WILZUARD YONAN WISMANTO ◽  
RAHMAT HIDAYAT ◽  
MAY ON TJIA ◽  
YASUMASA FUJIWARA ◽  
KOJI MURATA ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Enhancement Factor ◽  
Surface Plasmon Polariton ◽  
Incident Light ◽  
Silver Coating ◽  
Excitation Light ◽  
Enhanced Absorption ◽  
Pmma Matrix ◽  
Resonant Effect ◽  
Plasmon Polariton

We present the result of an experimental study on the photoluminescence of a thin layer of oxazine molecules doped into the poly(methyl methacrylate) (PMMA) matrix which is coated on top of sinusoidal silver grating. The surface plasmon polaritons that occur on the metallic grating surface were excited by a He-Ne laser of 633 nm wavelength. The effect of the grating was investigated by angle-resolved reflection and emission spectroscopy performed on the thin film samples with and without the grating. Incident light of both s- and p-polarizations were considered in this experiment and the measurement was performed in the reflection and the photoluminescence modes as well. The results exhibit remarkable resonant effect of photoluminescence enhancement over those observed from the sample with planar silver coating for both incident light polarizations. The much larger enhancement factor of ~50.0 found for the case of p-polarized light can be attributed to the combined contributions of surface plasmon polariton enhanced absorption of excitation light and the resonant coupling between the SPP and the fluorophore, while only the latter was operating in the case of s-polarized incident light which showed a smaller enhancement factor of 6.0.

Surface Plasmon Polaritons: Propagation Characteristics of Surface Plasmon Waves on Au and Ag at Optical Wavelengths

2011 ◽  
Vol 110-116 ◽  
pp. 764-768
Author(s):  
Niladri Pratap Maity ◽  
Reshmi Maity
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Noble Metals ◽  
Propagation Constant ◽  
Propagation Characteristics ◽  
Optical Wavelengths ◽  
Matlab Programming ◽  
Plasmon Polaritons ◽  
Strong Confinement ◽  
Surface Plasmon Waves

The existence of Surface Plasmons (SPs) is possible only if the metal have a negative dielectric constant at the corresponding optical frequency. In this paper the propagation characteristics of Surface Plasmon Waves (SPWs) which exists on noble metals like gold (Au) and silver (Ag) due to the formation of Surface Plasmon Polaritons (SPPs), have been evaluated theoretically and simulated with the help of MATLAB programming language. The variation of the propagation constant (PC), the attenuation coefficient (AC) and the penetration depth (PD) inside the metals and the dielectric has been determined. It has been found that highly conducting metals Au and Ag provide a strong confinement to the SPWs at optical frequencies.

Controlling the Surface Plasmon Absorption of Silver Nanoparticles via Green Synthesis Using Pennisetum purpureum Leaf Extract

2018 ◽  
Vol 772 ◽  
pp. 73-77
Author(s):  
Ruelson S. Solidum ◽  
Arnold C. Alguno ◽  
Rey Capangpangan
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Surface Plasmon ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Absorption Peak ◽  
Plasmon Absorption ◽  
Surface Plasmon Absorption

We report on the green synthesis of silver nanoparticles utilizing theP.purpureumleaf extract. Controlling the surface plasmon absorption of silver nanoparticles was achieved by regulating the amount of extract concentration and the molarity of silver nitrate solution. The surface plasmon absorption peak is found at around 430nm. The surface plasmon absorption peak have shifted to lower wavelength as the amount of extract is increased, while plasmon absorption peak shifts on a higher wavelength as the concentration of silver nitrate is increased before it stabilized at 430nm. This can be explained in terms of the available nucleation sites promoted by the plant extract as well as the available silver ions present in silver nitrate solution.

scholarly journals Photomorphogenesis in the Picocyanobacterium Cyanobium gracile Includes Increased Phycobilisome Abundance Under Blue Light, Phycobilisome Decoupling Under Near Far-Red Light, and Wavelength-Specific Photoprotective Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Gábor Bernát ◽  
Tomáš Zavřel ◽  
Eva Kotabová ◽  
László Kovács ◽  
Gábor Steinbach ◽  
...  
Keyword(s):  
Electron Transport ◽  
Growth Rates ◽  
Incident Light ◽  
Red Light ◽  
Photosynthetic Performance ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Strong Light ◽  
Antenna Size ◽  
Moderate Growth

Photomorphogenesis is a process by which photosynthetic organisms perceive external light parameters, including light quality (color), and adjust cellular metabolism, growth rates and other parameters, in order to survive in a changing light environment. In this study we comprehensively explored the light color acclimation of Cyanobium gracile, a common cyanobacterium in turbid freshwater shallow lakes, using nine different monochromatic growth lights covering the whole visible spectrum from 435 to 687 nm. According to incident light wavelength, C. gracile cells performed great plasticity in terms of pigment composition, antenna size, and photosystem stoichiometry, to optimize their photosynthetic performance and to redox poise their intersystem electron transport chain. In spite of such compensatory strategies, C. gracile, like other cyanobacteria, uses blue and near far-red light less efficiently than orange or red light, which involves moderate growth rates, reduced cell volumes and lower electron transport rates. Unfavorable light conditions, where neither chlorophyll nor phycobilisomes absorb light sufficiently, are compensated by an enhanced antenna size. Increasing the wavelength of the growth light is accompanied by increasing photosystem II to photosystem I ratios, which involve better light utilization in the red spectral region. This is surprisingly accompanied by a partial excitonic antenna decoupling, which was the highest in the cells grown under 687 nm light. So far, a similar phenomenon is known to be induced only by strong light; here we demonstrate that under certain physiological conditions such decoupling is also possible to be induced by weak light. This suggests that suboptimal photosynthetic performance of the near far-red light grown C. gracile cells is due to a solid redox- and/or signal-imbalance, which leads to the activation of this short-term light acclimation process. Using a variety of photo-biophysical methods, we also demonstrate that under blue wavelengths, excessive light is quenched through orange carotenoid protein mediated non-photochemical quenching, whereas under orange/red wavelengths state transitions are involved in photoprotection.

scholarly journals Improve the Hole Size-dependent Refractive Index Sensitivity  of Au-Ag Nanocages by Tuning the Alloy Composition

2021 ◽  
Author(s):  
Jianjun LI ◽  
Qiu-Xiang Qin ◽  
Guo-Jun Weng ◽  
Jian Zhu ◽  
Jun-Wu Zhao
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Electric Field ◽  
Alloy Composition ◽  
Geometric Parameters ◽  
Sensitivity Factor ◽  
Hole Size ◽  
Refractive Index Sensitivity ◽  
Electric Field Direction ◽  
Index Sensitivity

Abstract In this study, the nanoboxes is converted into Au-Ag alloy nanocages by increasing the hole size. Discrete dipole approximation (DDA) is used to study the extinction spectrum and the refractive index sensing characteristics of Au-Ag alloy nanocages with different geometric parameters. With the increase of Au component, the local surface plasmon resonance (LSPR) peak shows approximately linear redshift and the sensitivity factor shows approximately linear decrease. The refractive index sensitivity can be effectively controlled by the Au-Ag ratio at large hole size because the hole and cavity surfaces distribute more environmental dielectric components. Therefore, increasing the hole size and decreasing the Au-Ag ratio can improve the refractive index sensitivity. To explain the effect of alloy composition on the LSPR characteristics and the refractive index sensitivity, the local electric field distributions with different geometric parameters are plotted. We find that the electric field direction on the hole and cavity surfaces are controlled by the Au-Ag ratio and environmental dielectric constant. Moreover, the field vector on the hole and cavity surfaces are formed by the superposition of the incident field, the electric field generated by the oscillating electrons on the outer surface, and the polarized field in the environmental dielectric constant.

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