A5052217479- Semiconductor Quantum Structures and Devices
- Quantum Information and Cryptography
- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Semiconductor Lasers and Optical Devices
- Quantum Dots Synthesis And Properties
- Quantum optics and atomic interactions
- Photonic Crystals and Applications
- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Advanced Fiber Laser Technologies
- Quantum and electron transport phenomena
- Laser-Matter Interactions and Applications
- Quantum Mechanics and Applications
- Mechanical and Optical Resonators
- Optical Coatings and Gratings
- Laser Material Processing Techniques
- Advanced biosensing and bioanalysis techniques
- Nonlinear Optical Materials Studies
- Near-Field Optical Microscopy
- ZnO doping and properties
- Advanced Optical Sensing Technologies
- 2D Materials and Applications
- Semiconductor materials and devices
University at Buffalo, State University of New York
2015-2025
Guangdong University of Technology
2020
National Institute of Standards and Technology
2012-2017
Joint Quantum Institute
2012-2017
New York University
2016
Nanyang Technological University
2016
University of Maryland, College Park
2015
University of Konstanz
2007-2013
Carl Zeiss (Germany)
2007
Applied Photonics (United Kingdom)
2007
Block copolymer (BCP) derived periodic nanostructures with domain sizes larger than 150 nm present a versatile platform for the fabrication of photonic materials. So far, access to such materials has been limited highly synthetically involved protocols. Herein, we report simple, "user-friendly" method preparation ultrahigh molecular weight linear poly(solketal methacrylate-b-styrene) block copolymers by combination Cu-wire-mediated ATRP and RAFT polymerizations. The synthesized weights up...
Fundamental interactions induced by lattice vibrations on ultrafast time scales have become increasingly important for modern nanoscience and technology. Experimental access to the physical properties of acoustic phonons in terahertz-frequency range over entire Brillouin zone is crucial understanding electric thermal transport solids their compounds. Here we report generation nonlinear propagation giant (1 per cent) strain pulses hybrid gold/cobalt bilayer structures probed with surface...
The deposition of a dielectric overlayer on top Au/Co/Au multilayer films can significantly enhance the magnetic field induced modulation surface plasmon polariton (SPP) wave vector. This enhancement is analyzed as function thickness and associated SPP electromagnetic confinement redistribution. decrease in propagation distance taken into account by analyzing an adequate figure merit.
We measure the dynamics of a non-classical optical field using two-time second-order correlations in conjunction with pulsed excitation. The technique quantifies single-photon purity and coherence during excitation-decay cycle an emitter, illustrated here quantum dot. observe that for certain pump wavelengths, photons detected early have reduced compared to those later. A model indicates are due exciton recapture after initial emission within same pulse cycle.
We have fabricated all-dielectric high-Q optical pillar resonators with embedded colloidal CdSe/ZnS quantum dots or rods as light emitters by focused ion beam milling. Three-dimensional confinement and distinct microcavity modes are observed. Results from a waveguide model for the mode patterns their spectral positions in excellent agreement experimental data. Cavities elliptical cross sections show higher quality factors short axis direction than do circular of same cross-sectional area.
The time dynamics of spin-injected, electrically contacted quantum dots were investigated with a focus on the evolution photon statistics. Photon statistics can provide insights into whether device functions as an effective single-photon emitter or exhibits higher-order emissions. Through these investigations, we found that shape electrical excitation pulse has direct impact Specifically, rising edge corresponds to significantly higher number states, which decay much faster than single...
We present a detailed study on the structural, magnetic, and optical properties, as well electronic structure of epitaxial Co-doped ZnO films prepared by magnetron sputtering. Different preparation conditions were implemented in order to control concentration oxygen vacancies host lattice. Magnetization measurements indicate ferromagnetic behavior at low temperature for samples oxygen-poor whereas oxygen-rich show extremely small signal corroborating that ferromagnetism Zn1−xCoxO correlates...
The magnetic field is an interesting candidate for the development of active plasmonic devices as it able to modify surface plasmon polariton (SPP) wave vector. Both real and imaginary parts SPP vector are affected. Here, we have experimentally determined contribution both modulations in spectral range ${\ensuremath{\lambda}}_{0}=500$--1000 nm magnetoplasmonic systems consisting noble/ferromagnetic/noble multilayered metal films. We seen that part usually exceeds one, but longer wavelength...
We demonstrate femtosecond plasmonic interferometry with a novel geometry.The microinterferometer consists of tilted slit-groove pair.This arrangement allows for (i) interferometric measurements at single wavelength and (ii) unambiguous discrimination between changes in real imaginary parts the metal dielectric function.The performance is demonstrated by monitoring sub-picosecond dynamics hot electrons gold.
We used photoluminescence spectroscopy to resolve two emission features in CdSe/CdMnS/CdS and CdSe/CdS core/multi-shell nanoplatelet heterostructures. The from the magnetic sample has a positive circular polarization with maximum centered at position of lower energy feature. higher feature corresponding signature absorption spectrum; this is not case for low-energy have also studied temporal evolution these using pulsed-excitation/time-resolved technique investigate their recombination...
We present a theoretical analysis of femtosecond pump-probe experiments performed on single negatively charged quantum dot. The influence Coulomb-correlation effects as well carrier relaxation transient transmission change signals is investigated. Our model describes ultrafast disappearance the fundamental trion absorption due to instantaneous Coulomb renormalizations and delayed onset gain at same frequency, found in measurements. Going beyond previous experimental information, we predict...
Three dimensional light confinement and distinct pillar microcavity modes in the ultraviolet have been observed resonators with embedded colloidal ZnO quantum dots fabricated by focused ion beam milling. Results from a waveguide model for mode patterns their spectral positions are excellent agreement experimental data.
Systematic excitation power and temperature-dependent measurements on the emission lines of single self-assembled InP/(Al0.20Ga0.80)0.51In0.49P quantum dots embedded in micropillars have been performed. The were excited optically via a pulsed laser their luminescence was collected using micro-photoluminescence setup. exciton biexciton intensity, linewidth, spectral position investigated temperature range from 4 K up to 130 K. Single-photon is presented 100 K, confirmed by photon-statistics...
Atomic layer lithography is a recently reported new technology to fabricate deep-subwavelength features down 1-2 nm, based on combinations of electron beam (EBL) and atomic deposition (ALD). However, the patterning area relatively small as limited by EBL, fabrication yield not very high due technical challenges. Here we report an improved procedure flat metallic surfaces with sub-10 nm ALD processes. To demonstrate scalability manufacturing method, combine process large optical interference...
We present a study on the structural, magnetic, and optical properties, as well electronic structure of Co-doped ZnO films prepared by magnetron sputtering. Magnetization measurements performed at different temperatures indicate ferromagnetic paramagnetic behavior for samples oxygen-poor conditions whereas oxygen-rich show only corroborating that presence oxygen-related defects is essential ferromagnetism in Zn1-xCoxO. X-ray absorption spectroscopy (XAS) Co L2,3 edge together with...
As single-photon sources become more mature and are used often in quantum information, communications measurement applications, their characterization becomes important. Single-photon-like light is characterized by its brightness, two properties: the composition photon indistinguishability. While it desirable to obtain these quantities from a single measurement, currently or measurements required. Here, we simultaneously determine purity, indistinguishability, statistical distribution of...
We demonstrate up-conversion with no statistically significant background photons and a dynamic range of 15 decades. Near-infrared 920 nm were converted into the visible at 577 using periodically poled lithium niobate waveguides pumped by 1550 laser. In addition to achieving noiseless frequency up-conversion, we report high degree phase preservation (with fringe visibilities ≥ 0.97) single-photon level an up-converting Mach-Zehnder interferometer. This background-free process opens path...
We utilized time-resolved photoluminescence (TRPL) spectroscopy to study the excitonic circular polarization (PX) from CdSe/CdMnS core/shell nanoplatelets (NPLs) with a bilayer core. This allows an extensive of emission dynamics as function magnetic field, temperature, doping concentration, and excitation wavelength. In presence external pulsed below shell gap results in near-zero PX at all time delays. contrast, photon energy larger than rapid (100 ps) buildup which subsequently remains...
In this work, a chemical vapor deposition (CVD) method was developed for the synthesis of transition metal dichalcogenide alloy monolayers, with composition gradient in radial direction. The achieved by controlling substrate cooling rate during CVD growth. two types alloys, namely, WS2(1-x)Se2x and MoS2(1-x)Se2x, were found to exhibit an opposite gradient. This is attributed their different cohesive energies. A two-dimensional Ising model used explain growth mechanism, where ends modeled as...