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Active control of terahertz wave assisted by dielectric loaded plasmonic waveguide

Liu Huaiqing, Yang Mengya, He Xue, Jiang Youchao, Zhou Xiancun, Fu Maosheng

Optica Applicata

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2022

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Vol. 52, nr 1

89--99

EN

We propose and numerically investigate a directional coupler which consists of two dielectric loaded InSb based terahertz (THz) plasmonic waveguides. Owing to the permittivitly tunable property of InSb, the coupling strength between the two dielectric loaded plasmonic waveguides is affected by temperature, so the maximum power coupled from the input waveguide to the cross-waveguide and the correspondingly coupling length could be effectively tailored by altering temperature. Under different temperatures, this directional coupler could act as a thermally controlled terahertz wave switch or a 3-dB terahertz splitter around the frequency of 1.17 THz. This ultracompact and thermally controlled plasmonic directional coupler may find potential important applications in the highly integrated photonic circuits for terahertz system and technologies.

2

High sensitivity microsensor assisted by Fano resonance in InSb based terahertz plasmonic waveguide

Liu Huaiqing, Zhong Shuomin, Xu Gaoming

Optica Applicata

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2019

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Vol. 49, nr 4

585--596

EN

We propose a compact terahertz plasmonic structure comprising an InSb-dielectric-InSb waveguideside-coupled with two stub resonators. Due to the coherent interference of the splitting discrete andquasi-continuum modes, the reflection spectrum possesses a sharp asymmetric Fano resonance dip, which stems from the phase difference between the two stub resonators. Owing to the permittivity temperature dependent property of InSb, the Fano resonance dip can be actively controlled by tuning temperature. The physical features contribute to a highly efficient plasmonic sensor for both refractive index and temperature sensing. The microsensor yields a sensitivity of ̴2.9 THz/RIUand 1.8 × 10–3 THz/°C. This multiparameter high sensitivity microsensor may find important applications in medical sensing, biosensing and on-chip sensing working in terahertz region.

3

Improvement Optical and Electrical Characteristics of Thin Film Solar Cells Using Nanotechnology Techniques

Thabet Ahmed, Abdelhady Safaa, Ebnalwaled A.A., Ibrahim A. A.

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 4

625--634

EN

This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer. Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.

4

Optyczne własności nanokompozytów otrzymywanych metodą mikrowyciągania na bazie szkła NBP i domieszkowanych nanocząstkami Ag i jonami Er3+

Surma B., Gajc M., Pawlak D. A.

Materiały Elektroniczne

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2013

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T. 41, nr 4

34--49

PL

Opracowano technologię otrzymywania włókien szklanych z Na5B2P3O13 (NBP) oraz włókien NBP domieszkowanych nanocząstkami srebra i jonami Er3+ (NBP_Er3_nAg) przy użyciu metody mikrowyciągania. Metoda ta jest interesująca ze względu na możliwość uzyskania trwałych nanokompozytowych struktur 3D. Zbadano własności optyczne otrzymanych struktur. W czystym NBP obserwowano przesunięcie krawędzi absorpcji w kierunku długofalowym (do ~ 250 nm), który wiązany jest ze wzrostem zasadowości optycznej szkła wskutek zmiany wzajemnego stosunku niemostkowanych do zmostkowanych jonów tlenu. W strukturach NBP_Er3_nAg wzbudzanych linią 325 nm lasera He-Cd obserwowano transfer energii z widma emisyjnego szkła NBP do jonów Er3+ i nanocząstek srebra. Stwierdzono około dwukrotny wzrost emisji dla przejść 4I13/2-4I15/2 w obecności nanocząstek Ag w wyniku transferu energii z nAg do jonów Er3+ . Po raz pierwszy zaobserwowano również w 300K emisję przy 615 nm pochodzącą od przejść 4G11/2-4I11/2 . Ponad pięciokrotne wzmocnienie występuje w obecności silnego piku związanego z LSPR wskutek transferu energii z nanocząstek nAg na poziom 4G11/2 jonu erbu. Przy wzbudzaniu rezonansowym dla przejść 4I15/2-4F7/2 linią 488 nm emisja przy 1532 nm pochodzi głównie od wzbudzenia poziomu 4I13/2 w wyniku relaksacji wielofononowej z poziomu 4F7/2 , a obserwowane gaszenie emisji przy 1532 nm wynika z transferu energii z jonów Er3+ do grupy hydroksylowej OH, transferu pomiędzy jonami erbu oraz transferu do nanocząstek srebra.

EN

A new technology of the manufacturing of Na5B2P3O13 (NBP) glass fibers doped with erbium ions and silver nanoparticles (nAg) was elaborated by using micro-pulling method (μ - PD). The method is interesting as it allows to obtain the solid and stable 3D nanocomposite structures. The optical features of these structures were studied. A “red shift” of the absorption band gap observed for pure NBP fibers was related to the change in the optical basicity of the glass due to the change in the relation between bridging and non-bridging oxygen. In the plasmonic composite doped with nAg and Er3+ (NBP:Er3:nAg) excited with 325 nm line of He-Cd laser a radiative energy transfer was observed from matrix emission to Er3+ and nAg. Twofold increase of the emission for 4I13/2-4I15/2 transition was stated in presence of nAg. For the first time the emission at 615 nm for 4G11/2 -4I11/2 transitions was observed and more than fivefold increase in the intensity of this line occurred in the presence of the strong local surface plasmon resonance (LSPR) due to energy transfer from nAg. During excitation with 488 nm line the intensity of the emission at 1536 nm (4I13/2-4I15/2 transitions) was mainly controlled by the energy transport from Er3+ ions to hydrocarboxyl group OH as well as energy migration between erbium ions.