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We present the detailed procedure for modeling of separate absorption and multiplication (SAM) GaN/AlGaN avalanche photodiode (APD). The bias-dependent spectral responsivity characteristics are obtained by using the constructed two-dimensional numerical model. It is found that the spectral responsivities with wavelength from 240 to 450nm are entirely increased with the increased bias.
Diffraction efficiencies of antireflective microstructures (AMSs) were calculated using a rigorous coupled wave analysis (RCWA) method for mid-infrared applications. The results show the effect of height, period, and shape of AMSs on the reflection. We also discuss optimum geometry of AMSs for mid-infrared application.
This paper presents a minority carrier lifetime extraction method using transient photovoltage method. The excitation light source is a picosecond pulsed infrared laser. A parallel resistance has been introduced to minimize the effect of the equivalent junction series resistance effect. A storage oscilloscope has been used to record the photovoltage of the photodiode. By fitting the exponentially...
A GaAs/InGaAs/InAs quantum dots - quantum well in double barrier is discussed in this paper, because it has shown a specific inner multiplication in test and lower dark current accompanied by high current gains. The S (signal)/D (dark current) has reached 106 at a certain light power and bias. For further know its electronic transport and photoelectric characteristic, we are contrastive analysis sensitivity...
Strong disparity in electron and hole transport characteristics and excessive depth of optically active quantum wells (QWs) in III-nitride materials are the main causes of inhomogeneous carrier distribution and uneven QW injection in multi-QW light emitters of visible range. Both polar and nonpolar LED structures suffer from inhomogeneous injection. Undoped wide-bandgap electron blocking layer (EBL)...
A dynamic model of a bulk reflective SOA is described. The model includes spontaneous emission and uses full bandstructure based calculations of the active material gain coefficients. The model is used to simulate the use of an RSOA to modulate an input CW lightwave at multi Gb/s data rates using bias current modulation. Simulated eye diagrams show good agreement with experiment.
We propose a plasmonic refractive index-sensitive nanosensor based on the electromagnetically induced transparency (EIT) of waveguide resonator systems. The structure consists of one tooth-shaped cavity as well as the bus and stub metal-insulator-metal waveguides. By adjusting the structural geometry, it is demonstrated that the controllable transmission of EIT response can be obtained with the finite-difference-time-domain...
Plasmonic waveguides supporting gap surface plasmons (GSPs) localized in a dielectric spacer between metal films are investigated numerically and the waveguiding properties at telecommunication wavelengths are presented. Especially, we emphasize that the mode confinement can advantageously be controlled by the waveguide width and the dielectric spacer thickness and thus allows for straightforward...
We present an ultra-compact modulator with a length of 15 nm by utilizing the squeezing and tunneling ability of the Epsilon-Near-Zero metamaterial. The finite-different time-domain simulations show the insertion loss is roughly −0.27 dB while the 3-dB extinction ratio is obtained with a 0.8 V gate voltage. The device's footprint is as small as 0.01 µm2. This modulator consumes low power and can potentially...
In this paper, a kind of twisted split-ring chiral metamaterials is proposed to obtain integratable broadband circle dichroism. With coupling among closely spaced twisted split-rings, a broadband circle dichroism is achieved owning to the combined effect of Bragg resonance and internal resonance.
This work presents a self-consistent algorithm for the simulation of responsivity and detectivity of InGaAs/GaAs strained multi-period Quantum Well Infrared Photodetectors. This algorithm takes into account the fundamental mechanisms involved in the InGaAs/GaAs detector detection process. We have calculated a practical InGaAs/GaAs detector by using this algorithm. The obtained results were in good...
We present a new implementation of the eigenmode expansion technique for modeling Kerr-nonlinear waveguide structures. The formulation uses numerically stable scattering matrices and a perturbation approach based on the rigorous coupled-mode theory.
The absorption enhancements of silicon layer in silicon solar cells with Al sphere nanoparticles are studied by the finite difference time domain (FDTD) method. The results show that the light absorption of silicon is significantly improved due to the localized surface plasmon (LSP) resonance. The relations of the absorption enhancement with the parameters of nanoparticles are thoroughly analyzed...
A novel design of nanohole polymer solar cell (NHPSC) is reported for light trapping improvement. The proposed design has shown a considerable enhancement in the optical and electrical parameters of the polymer solar cell based on a conventional blend of poly-3-hexylthiophene/ [6, 6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) as an active material. In this study, 3D finite difference time domain...
This paper studies the influence of gain on transmission of electromagnetic waves through the nanocavity placed between two reflectors. The reflectors consist of alternating nano-layered structure that contains dispersive negative and non-dispersive positive refractive index materials. Here, we analyze transmission of the structure by utilizing transfer matrix method on 103 THz regime of frequency.
Calculation of the higher order modes for the Time Dependent Schrödinger's equation (TDSE). The Imaginary Time Propagation (ITP) method is used to solve the TDSE where this reduces the computational effort required to solve the TDSE. Also using the adjoint variable method the energy level sensitivity for higher order modes has been calculated for the same simulation.
In this paper, a novel design of hexagonal cylindrical plasmonic solar cell (HC-PSC) is investigated and analysed by using 3D finite difference time domain method. The aim of our work is to get maximum absorption of thin film solar cell by scattering the light from metal nanoparticles. Therefore the effects of the structure geometrical parameters on the absorption are investigated. The numerical results...
Nanophotonic light trapping methods play a key role in high thin film solar device. Even many parameters are discussed in cell designs; the shape of the semiconductor grating is rarely included. In this paper, we investigated the shape-induced effects on the absorption of solar cell and demonstrated that even for the structures at the nanometer scale; the shape of the grating is also an indispensable...
In this paper, we report the optical properties of a Silicon (Si) solar cell when varying the configuration (hexagonal and square) of a micro pillar array on the cell surface using the FDTD technique. It was found that the hexagonal configuration gives better performance.
The feasibility of combining a semiconductor optical amplifier (SOA) with a single passive microring resonator (MRR) to equalize the amplitude and phase fluctuations of the distorted signal in free space optical (FSO) communications is theoretically investigated and demonstrated. The numerical simulation conducted for this purpose allows to specify the MRR radius and detuning so that the critical...
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