Coherent anti-Stokes Raman scattering microscopy is performed on glassy systems of poly(methylmethacrylate) colloidal particles in density- and refractive-index-matched solvents. Samples are prepared with varying amounts of linear polystyrene, which induces a depletion driven attraction between the nearly hard-sphere particles. Images collected over several hours confirm the existence of a reen...

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their stru...

Highly ordered freestanding honeycomb films with asymmetric through-pore structures were prepared from polystyrene/gold-nanoparticles (PS/AuNPs) nanocomposite at an air/water interface using a one-step interfacial self-assembly method.

We report a simple and scalable method for the fabrication of spiral-type chiral plasmonic oligomers based on the stepwise colloid sphere lithography technology. Through carefully adjusting the azimuthal angle Φ of polystyrene (PS) sphere array monolayer and the deposition thickness k n , the chiral plasmonic oligomers composed of four achiral particles can be successfully fabricated on a desir...

An optical technique to characterize the accretion of material by microparticles is described. Experiments on the absorption of water vapor by single levitated polystyrene microparticles are reported as examples of an application of the technique. The optical resonant frequencies of the microparticles are perturbed by the accretion of material and the observed shifts are used to characterize th...

Confinement Effects on Chain Entanglement in Free-Standing Polystyrene Ultrathin Films Jeremy M. Rathfon, Robert W. Cohn, Alfred J. Crosby, Jonathan P. Rothstein, and Gregory N. Tew* Department of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States ElectroOptics Research Institute and Nanotechnology Center, Unive...

In the context of a bioreactor, cells are sensitive to cues from other cells and mechanical stimuli from movement. The ability to provide the latter in a discrete fluidic system presents a significant challenge. From a prior finding that the location of the focus of a laser below particles relative to the beam axis producing a pushing effect in a predominant lateral sense, we advance an approac...

Determination of The transmittance values measured in IR reflectionabsorption (RA) spectra were used to determine the optical constants of dielectric films laid on solid substrates. In order to obtain the optical constants of polystyrene films laid on steel we used dispersion analysis. In this case, the optical constants are obtained from IR spectrum recorded at a single incidence angle. The us...

A simple and versatile method is developed for preparing anisotropic polymer particles by pressing polymer microspheres at elevated temperatures. Polystyrene (PS) microspheres are used to demonstrate this approach. Depending on the mechanical deformation and wetting of the polymers on the substrates, polymer structures with special shapes such as barrel-like or dumbbell-like shapes can be prepa...