Ultrafast nonlinear spectroscopy
Ultrafast nonlinear spectroscopy
Ultrafast 2-D IR spectroscopy
Spectroscopy with submolecular resolution using inelastic STM
Condensed Matter Physics
Non-linear optical (CARS) microscopy
Energy Science; Theory & Computation
Interfacial & Bioanalytical Chemistry (IBAC) photochemical properties
Surface-Enhanced Raman Spectroscopy
Condensed Matter Physics
Photocatalysis, Time-Dependent Density Functional Theory
Time-resolved scannning tunneling microscopy, Single molecule Raman Spectroscopy, Ultrafast electron dynamics in plasmonic materials
Nonlinear microscopy with applications in material science and biomedicine, High-resolution spectroscopy. Nonlinear plasmonics.
Ultrafast nonlinear spectroscopy, multidimensional infrared spectroscopy and nonlinear microscopy.
Studying the use of optical forces to investigate light-matter interaction at the single molecule level. Development of novel Tip Enhanced Raman (TERS) techniques such as stimulated-TERS and their application towards single molecule spectroscopy. Research areas of interest: Near-field optics, plasmonics, scanning probe microscopy and spectroscopy.
Study chemical properties of small molecules on metal surfaces and nanocatalysts using first-principles calculations.
Four wave mixing spectroscopy with a single molecule sensitivity (background-free time resolved CARS with wavelength-tunable ultrashort laser pulses);
high-order-harmonic generation from metal nanotips.
My research uses surface-enhanced ultrafast nonlinear spectroscopies to study the effect of plasmonic enhancement on ultrafast dynamics in nanomaterials relevant to photovoltaics and photocatalysis. The goal is to push the sensitivity of these measurements toward the single molecule regime.
The dynamics of surface plasmons with sub-wavelength spatial resolution and sub-femtosecond temporal precision by using PEEM and LEEM.
Ultrafast spectroscopy and light-matter interactions in plasmonic nanoparticles. Focusing on single molecule SERS/TERS in different nanoparticle geometries and development of ambient light induced fs-STM microscopy.
The goal of my research is to tackle challenging problems in the general area of condensed matter theory, using electromagnetic simulation tools and developing theoretical models for the study of the optical response of metallic nanostructures, plasmonic, excitonic, and hybrid systems.
Ultrafast Nonlinear Spectroscopy, Nonlinear microscopy, Surface Enhanced Nonlinear spectroscopy
My goal in the Van Duyne group is to use ultrafast spectroscopy to investigate vibrational dynamics of chemical systems deposited on nanoparticle substrates that provide surface enhancement effects.
I study the ultrafast nonlinear optical processes of nano-structured materials and work to extend this to the single molecule regime through the measurement of light-induced changes in the attractive force between a cantilevered atomic force microscope tip and the polarizable medium.
Femtosecond Light-Molecule Interaction with a Tunable Wavelength Femtosecond Laser Coupled STM
Theory and method development as it relates to light/matter interactions. Primarily concerned with the response of molecules coupled to plasmonic nanoparticles.
My research is focused on the characterization and application of gold and silver plasmonic nanocrescents. The localized surface plasmon resonances (LSPR) of these structures have been shown to be polarization dependent, leading to selective excitation of unique resonance modes, and maintain nanoscale resonance behavior into microscale dimensions, resulting in resonance frequencies over a visible to infrared frequency range. We are working with the Ge and Potma groups to integrate nanocrescent substrates into surface enhanced sum frequency vibrational spectroscopy.
My research involves investigating the coupling of light to surface plasmon polaritons via tailored, transient optical gratings. This coupling scheme is then utilized to remotely launch surface plasmons at nanojunctions to drive and monitor space-time resolved chemistry.
My current research efforts are focused on using a low-temperature ultra-high vacuum Scanning Tunneling Microscope (STM) coupled to a femtosecond laser and CCD camera to explore the electronic states, charge transfer, light emission and absorption, plasmon resonance and catalysis enhancement of single molecules and nanostructures with sub-Angstrom spatial resolution. Presently we are investigating the spatial dependence of plasmon-enhanced catalysis in the vicinity of gold nanoparticles.
Ultrafast photoemission electron microscopy of plasmonic nanostructures
My research involves exploring different plasmonic substrate systems for use in the new technique of surface-enhanced femtosecond stimulated Raman spectroscopy. Our aim to to watch chemical reactions on the femtosecond timescale of nuclear motion by combining the plasmonic enhancements provided by surface- and tip-enhanced Raman spectroscopy with the time resolution of ultrafast spectroscopies.
I am doing force detection of sample optical response using AFM.
Studying optically induced force (Image force, Raman force, Plasmonic force, etc) microscopy and spectroscopy by combining atomic force microscope with optical microscope. Key words: optical gradient forces (plasmonic force, image force, Raman force), near-field optics, nonlinear optics, AFM
I am currently utilizing ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS) to solve challenging chemical problems that require pushing the limits of space and time. UHV-TERS allows pristine samples to be prepared and studied with Ångstrom-scale topographical resolution, nanometer spectroscopic resolution, sensitivity down to a single-molecule, and currently I am working towards incorporating picosecond temporal resolution.
I am investigating the development of a gold nanocrescent/alumina substrate for surface enhanced spectroscopy investigations of catalytically-active triphenylphosphine-stabilized gold nanoclusters.
I study plasmon dynamics on STM tips via grating coupling of femtosecond laser pulses in an effort to produce coherent field emission of electrons at the tip apex for future applications in time resolution of tunneling measurements at the single molecule level.
Research and development of a Radio Frequency Scanning Tunneling Microscope(RF-STM) with the capability to detect photon induced tunneling current for the purposes of combining femtosecond temporal resolution and sub-angstrom spatial resolution.
My research concerns incorporating femtosecond temporal resolution with nanoscale surface characterization. Tip-enhanced Raman spectroscopy (TERS) is a technique through which the chemical properties of surface-bound molecules can be probed spectroscopically with spatial resolution on the order of single nanometers. While TERS is typically poor in temporal resolution, we have made advances toward the integration of ultrafast spectroscopic techniques, which will allow us to spatially resolve ultrafast surface dynamics relevant to many technologies.
My research focuses on the self-assembly of Au nanoparticle and Ag nanocube dimer structures to produced localized fields that will lead to enhanced Raman spectroscopy signals.
I propose to explore the rectifying abilities of DBDT for implementation in solar energy technology. Major characterization methods include STM and AFM experiments.
My research currently involves photostability studies of four-wave mixing substrates for surface-enhanced stimulated raman spectroscopy (SE-FSRS) and surface-enhaced coherent raman scattering (SE-CARS). I am also conducting theoretical calculations of non-equilibrium electron dynamics in order to gain insight into rapid thermalization processes occurring within experimental ultrafast systems.
I use a scanning tunneling microscope to study single molecule electron dynamics and Tip Enhanced Raman Spectroscopy. I am also investigating an intrinsically conductive metalorganic polymer for its use as molecular wires.
Improving charge transport in quantum dot (QD) solids for solar energy conversion devices. Using QD materials, our group are interested in working with the Apkarian group to perform fundamental studies such as single dot spectroscopy and charge carrier dynamics.
I study near field enhancement and control in plasmonic nanostructures for spectroscopy and imaging applications. Currently my research focuses on the asymmetry of plasmonic nano-dumbbells and excitation of multipolar fields in single molecule SERS experiments.
Time Resolved Four Wave Mixing Spectroscopy (CARS, Transient Grating) with Visible Femtosecond Pulses. Current systems of interest include: Bulk Magnesium Porphyrin, Silicon Naphthalocyanine in solution, Plasmon Propagation along thin film gold using four wave mixing to create an optically controlled grating to couple a third beam to Surface Plasmon Polaritons.
Research specializing in femtosecond laser coupled STM, STM induced photon emission, single molecule spectroscopy / microscopy.
STM studies of coupling in QD oligomers, Inductive effect of organic ligands for quantum dots.