相关论文: Excitonic nonlinear absorption in CdS nanocrystals…
We investigate the polarization dependence of optical nonlinearity enhancement for a uniaxial anisotropic composite of metal nanocrystals in a dielectric host. Three cases are distinguished depending on whether the polarization is parallel,…
We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods : the first one,…
Material absorption is a key limitation in nanophotonic systems; however, its characterization is often obscured by scattering and diffraction loss. Here we show that nanomechanical frequency spectroscopy can be used to characterize the…
Effective surface-passivation of PbS nanocrystals in aqueous colloidal solution has been achieved following treatment with CdS precursors. The resultant photoluminescent emission displays two distinct components, one originating from the…
The present paper deals with the results of a research work on the optical properties of colloidal InP/ZnS nanocrystals stabilized with a heterobifunctional polyvinylpyrrolidone polymer. We have analyzed the absorption and photoluminescence…
Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide band-gap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive index, two-photon…
Incommensurate charge density waves (CDW) have the extraordinary ability to display non-Ohmic behavior when submitted to an external field. The mechanism leading to this non trivial dynamics is still not well understood, although recent…
Large surface to volume ratios of semiconductor nanocrystals cause susceptibility to charge trapping, which can modify luminescence yields and induce single-particle blinking. Optical spectroscopies cannot differentiate between bulk and…
Accurate energy-size dependence of excitonic transitions in semiconductor nanocrystals in the strong confinement regime using classical theoretical approaches such as effective mass approximation, tight binding, or empirical…
In this article, we studied intensity dependent third order nonlinear optical response in ternary As40Sb7Se53 and As40Sb10Se50 chalcogenide glasses by employing nanosecond Z-scan technique. At low intensity, we observed saturable absorption…
This work presents a cost-effective alternative technology for the formation of nanostructured semiconductor materials for tunable light emitting devices. CdS and ZnS semiconducting colloid nanoparticles coated with organic shell,…
As a rapidly expanding family of two dimensional (2D) materials, MXenes have recently gained considerable attention due to their appealing properties. Here, by developing a solution based coating method that enables transfer free and layer…
Through systematic experimental and theoretical studies of layer-thickness-dependent absorption in semiconducting MoSe$_2$ and WS$_2$ across the visible to near-infrared spectral range, we demonstrate a universal absorption behavior in…
Semiconductor nanoplatelets possess exceptional optical properties that make them promising candidates for next-generation optoelectronic applications. However, unlike quantum dots where absorption spectroscopy alone can determine both size…
Herein we describe a novel spinning pump-probe photoacoustic technique developed to study nonlinear absorption in thin films. As a test case, an organic polycrystalline thin film of quinacridone, a well-known pigment, with a thickness in…
Determination of optical absorption cross-section is always among the central importance of understanding a material. However its realization on individual nanostructures, such as carbon nanotubes, is experimentally challenging due to the…
We evaluate the rate of the absorption of an optical nanofiber mode by a Cs atom in an electric quadrupole transition. With the Cs atom localized near the outer surface of the optical nano-fiber, an interaction occurs between the atomic…
We obtained over 90 hours of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope (HET). Observations were taken in transit and out of transit, and we analyzed the differenced spectra---i.e., the…
Nonlinear absorption in four and five energy level systems have been studied with the aid of steady-state rate equation approach. We report on the tunability of saturable and reverse saturable absorption as a function of spectroscopic…
Since thin-film silicon solar cells have limited optical absorption, we explore the effect of a nanostructured back reflector to recycle the unabsorbed light. As a back reflector we investigate a 3D photonic band gap crystal made from…