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Rigorous optical modelling of long-wavelength infrared photodetector with 2D subwavelength hole array in gold film

Janaszek Andrzej, Wróbel Piotr, Dems Maciej, Ceylan Omer, Gurbuz Yasar, Kubiszyn Łukasz, Piotrowski Józef, Kotyński Rafał

Opto-Electronics Review

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2024

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Vol. 32, No. 1

art. no. e148831

EN

The quantum efficiency of an InAs/InAsSb type-II superlattice (T2SL) high operating temperature (HOT) long-wavelength infrared (LWIR) photodetector may be significantly improved by integrating a two-dimensional subwavelength hole array in a metallic film (2DSHA) with the detector heterostructure. The role of the metallic grating is to couple incident radiation into surface plasmon polariton (SPP) modes whose field overlaps the absorber region. Plasmon-enhanced infrared photodetectors have been recently demonstrated and are the subject of intensive research. Optical modelling of the three-dimensional detector structure with subwavelength metallic components is challenging, especially since its operation depends on evanescent wave coupling. Our modelling approach combines the 3D finite-difference time-domain method (FDTD) and the rigorous coupled wave analysis (RCWA) with a proposed adaptive data-point selection for calculation time reduction. We demonstrate that the 2DSHA-based detector supports SPPs in the Sommerfeld-Zenneck regime and waveguide modes that both enhance absorption in the active layer.

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A review of the current state-of-the-art in Fano resonance-based plasmonic metal-insulator-metal waveguides for sensing applications

Adhikari R., Chauhan D., Mola G. T., Dwivedi R. P.

Opto-Electronics Review

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2021

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Vol. 29, No. 4

148--166

EN

Fano resonance is an optical effect that emerges from the coherent coupling and interference (constructive and destructive) between the continuous state (background process) and the Lorentzian state (resonant process) in the plasmonic waveguide-resonator system. This effect has been used in the applications like optical sensors. These sensors are extensively used in sensing biochemicals and gases by the measurement of refractive index changes as they offer high sensitivity and ultra-high figure of merit. Herein, we surveyed several plasmonic Fano sensors with different geometries composed of metal-insulator-metal waveguide(s). First, the resonators are categorized based on different architectures. The materials and methods adopted for these designs are precisely surveyed and presented. The performances are compared depending upon the characterization parameters like sensitivity and figure of merit. Finally, based on the survey of very recent models, the advances and challenges of refractive index sensing deployed on Fano resonances are discussed.

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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.

4

Interference effect in a dual microresonator-coupled Mach-Zehnder interferometer

Lu Y., Huang X., Fu X., Wen W., Yao J.

Optica Applicata

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2012

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Vol. 42, nr 1

23-29

EN

We present a theoretical study of interference effect in a Mach-Zehnder interferometer in which two microresonators are side coupled to both arms of the interferometer. The results show that sharp asymmetric Fano resonance, coupled resonator induced transparency and absorption effects can be created in such a structure. We demonstrate that these effects arise from interference between a resonance mode and a continuing propagating mode with asymmetric phase difference, destructive interference between two overcoupled resonance modes, and constructive interference between an overcoupled resonance mode and an undercoupled mode or a continuing propagating mode with symmetric phase differences, respectively. These effects may offer a better understanding of the analogous effects in atomic medium and also make optical resonators a potential device to utilize these effects.