Robust median filtering detection based on the difference of frequency residuals
Sign Up to like & getrecommendations! Published in 2018 at "Multimedia Tools and Applications"
DOI: 10.1007/s11042-018-6831-6
Abstract: Recently, the detection of median filtering (MF), which is a popular nonlinear denoising manipulation, has attracted extensive attention from researchers. Several detectors with satisfying performance have been developed, while most of them need to train… read more here.
Keywords: detection; frequency residuals; frequency; median filtering ... See more keywords
Physical Approaches to Designing a Two-Cascade Terahertz Laser Generating Difference-Frequency Radiation in a Nonlinear Optical ZnGeP2 Crystal
Sign Up to like & getrecommendations! Published in 2018 at "Russian Physics Journal"
DOI: 10.1007/s11182-018-1311-z
Abstract: An optical layout of a two-cascade frequency converter of the mid-IR laser radiation into the terahertz (THz) radiation is proposed. In the first stage it is assumed to convert the Tm:YLF-laser frequency in a Cr+2:ZnSe… read more here.
Keywords: frequency; difference frequency; nonlinear optical; two cascade ... See more keywords
Dynamic modeling of a terahertz quantum cascade laser based on difference frequency generation
Sign Up to like & getrecommendations! Published in 2018 at "Optik"
DOI: 10.1016/j.ijleo.2017.11.126
Abstract: Abstract In this paper, we consider a terahertz quantum cascade laser based on difference frequency generation and investigate theoretically the transient dynamics of its quantum cascade laser mid-infrared pumps and terahertz wave generated via intra-cavity… read more here.
Keywords: frequency generation; quantum cascade; difference frequency;
Difference Frequency Generation-based ultralow threshold Optical Bistability in graphene at visible frequencies, an experimental realization
Sign Up to like & getrecommendations! Published in 2019 at "Journal of Molecular Liquids"
DOI: 10.1016/j.molliq.2019.03.167
Abstract: Abstract We experimentally show that Difference Frequency Generation (DFG) can efficiently occur in a graphene ink for a visible pump-probe radiation in consequence of the second order nonlinear optical response of graphene. DFG induces the… read more here.
Keywords: optical bistability; frequency generation; generation; graphene ... See more keywords
Analysis of difference-frequency wave loads and quadratic transfer functions on a restrained semi-submersible floating wind turbine
Sign Up to like & getrecommendations! Published in 2021 at "Ocean Engineering"
DOI: 10.1016/j.oceaneng.2021.109165
Abstract: Abstract One of the concerns regarding numerical simulation of floating wind turbines (FWTs) in waves is underprediction of resonant responses in the low-frequency range. In the present work, the difference-frequency wave loads on a restrained… read more here.
Keywords: engineering; frequency; wave loads; difference frequency ... See more keywords
Broadband gate-tunable terahertz plasmons in graphene heterostructures
Sign Up to like & getrecommendations! Published in 2018 at "Nature Photonics"
DOI: 10.1038/s41566-017-0054-7
Abstract: Graphene, a unique two-dimensional material comprising carbon in a honeycomb lattice1, has brought breakthroughs across electronics, mechanics and thermal transport, driven by the quasiparticle Dirac fermions obeying a linear dispersion2,3. Here, we demonstrate a counter-pumped… read more here.
Keywords: gate tunable; broadband gate; graphene; gate ... See more keywords
Coupled oscillators driven with difference-frequency parametric position feedback
Sign Up to like & getrecommendations! Published in 2017 at "Journal of Applied Physics"
DOI: 10.1063/1.4991887
Abstract: We examine theoretically and measure experimentally the instability regions for a pair of parametrically driven mechanical oscillators on an air track. We take the position of the second mass, multiply it by cos (ω_Dt), and apply… read more here.
Keywords: difference; coupled oscillators; system; frequency ... See more keywords
The possibility of difference frequency generation in the GaAs phonon reststrahlen band within dual-chip GaAs-based lasers
Sign Up to like & getrecommendations! Published in 2020 at "Journal of Applied Physics"
DOI: 10.1063/5.0010583
Abstract: We consider the possibility of difference frequency generation in the GaAs phonon reststrahlen band within dual-chip GaAs-based lasers at room temperature. Sufficient generation efficiency is achieved via the resonant increase of GaAs second order nonlinear… read more here.
Keywords: frequency generation; possibility difference; gaas; generation ... See more keywords
Phase-Matched Mid-Infrared Difference Frequency Generation Using a Nanostructured Gallium Arsenide Metamaterial With Nanoholes
Sign Up to like & getrecommendations! Published in 2020 at "IEEE Photonics Journal"
DOI: 10.1109/jphot.2020.2992192
Abstract: Phase-matched wavelength conversion is achieved in difference frequency generation (DFG) in a structure of gallium arsenide (GaAs) with periodic arrays of nanoholes. Linear properties (refractive indices) of the structure are determined from the S-parameters of… read more here.
Keywords: frequency generation; gallium arsenide; phase matched; difference ... See more keywords
Accurate Iterative Inverse Scattering Methods Based on Finite-Difference Frequency-Domain Inversion
Sign Up to like & getrecommendations! Published in 2022 at "IEEE Transactions on Geoscience and Remote Sensing"
DOI: 10.1109/tgrs.2021.3121766
Abstract: Two accurate finite-difference frequency-domain (FDFD)-based iterative inverse methods, referred to as FDFD-based iterative method (FIM) and distorted FDFD-based iterative method (DFIM), are proposed for electromagnetic inverse scattering. They can be considered as FDFD-based versions of… read more here.
Keywords: difference; finite difference; frequency domain; difference frequency ... See more keywords
Implementation of a finite difference frequency domain mode solver incorporating subpixel smoothing.
Sign Up to like & getrecommendations! Published in 2022 at "Applied optics"
DOI: 10.1364/ao.472063
Abstract: Finite difference frequency domain (FDFD) mode solvers are straightforward to implement but can suffer from slow convergence when applied to high-contrast refractive index structures. In this work, we show how subpixel smoothing can improve the… read more here.
Keywords: frequency domain; finite difference; mode solver; mode ... See more keywords