Related papers: Modeling upconversion of erbium doped microcrystal…
Upconversion of sub-band-gap photons constitutes a promising way for improving the efficiency of silicon-based solar cells beyond the Shockley-Queisser limit. 1500 to 980 nm upconversion by trivalent erbium ions is well-suited for this…
We propose a simplified rate-equation model for the 1500 nm to 980 nm upconversion in Er$^{3+}$. The simplifications, based on typical experimental conditions as well as on conclusions based on previously published more advanced models,…
We investigate plasmon resonances in gold nanoparticles to enhance the quantum yield of upconverting materials. For this purpose, we use a rate equation model that describes the upconversion of trivalent erbium based upconverters. Changes…
The enhancement of Er$^{3+}$-based up-conversion for photovoltaics in multilayer porous silicon photonic structures is considered theoretically and experimentally. Transfer matrix simulations are used to assess the increased photonic…
We develop a theoretical description of a device for coherent conversion of microwave to optical photons. For the device, dopant ions in a crystal are used as three-level systems, and interact with the fields inside overlapping microwave…
The phenomenon of upconversion, in which a system sequentially absorbs two or more photons and emits a photon of a higher frequency, has been used in numerous applications. These include high-resolution non-destructive bioimaging,…
Recent reports of upconversion and white light emission from graphitic particles warrant an explanation of the physics behind the process. We offer a model, wherein the upconversion is facilitated by photo-induced electronic structure…
Understanding and modeling energy transfer mechanisms in rare-earth-doped nanomaterials is essential for advancing luminescent technologies used in bioimaging, optical thermometry, and solid-state lasers. In this work, we investigate the…
The equilibration of electronic carriers in metals after excitation by an ultra-short laser pulse provides an important class of non-equilibrium phenomena in metals and allows measuring the effective electron-phonon coupling parameter.…
Frequency upconversion, which converts low-energy photons into higher-energy ones, typically requires intense coherent illumination to drive nonlinear processes or the use of externally driven optoelectronic devices. Here, we demonstrate an…
Frequency up-conversion of few low-energy photons into a single high-energy photon, greatly contributes to imaging, light sources, detection and other fields of research. However, it offers negligible efficiency when up-converting many…
We theoretically investigate up-conversion process of entangled two photons on a dimer molecule, which is coupled by a cavity or nanoscale metallic structure. Within one-dimensional input-output theory, the propagators of the photons are…
We demonstrate an efficient and continuous microwave photon to electron converter with large quantum efficiency ($83\%$) and low dark current. These unique properties are enabled by the use of a high kinetic inductance disordered…
Up-conversion nanocrystals (UCNCs) are a new class of nonlinear optical materials converting low energy excitation to high energy emission. Recent advances in synthesis techniques enable a control over size, shape, emission color purity as…
We employ a detailed balance approach to model a single-junction solar cell with a realistic narrow-band, non-unity-quantum-yield upconverter. As upconverter bandwidths are increased from 0 to 0.5 eV, maximum cell efficiencies increase from…
Frequency up-conversion of a few low-energy photons into a single high-energy photon contributes to imaging, light sources, and detection. However, the up-converting of many photons exhibits negligible efficiency. Up-conversion through…
Processes involving ultrafast laser driven electron-phonon dynamics play a fundamental role in the response of quantum systems in a growing number of situations of interest, as evidenced by phenomena such as strongly driven phase…
Free electron beams such as those employed in electron microscopes have evolved into powerful tools to investigate photonic nanostructures with an unrivaled combination of spatial and spectral precision through the analysis of electron…
Gold nanoparticles emit broad-band upconverted luminescence upon irradiation with pulsed infrared laser radiation. Although the phenomenon is widely observed, considerable disagreement still exists concerning the underlying physics - most…
Frequency conversion (FC) and type-II parametric down-conversion (PDC) processes serve as basic building blocks for the implementation of quantum optical experiments: type-II PDC enables the efficient creation of quantum states such as…