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Displaying 76 - 100 of 105

Surface plasmon polariton laser based on a metallic trench Fabry-Perot resonator

October 6, 2017
Author(s)
Wenqi Zhu, Ting Xu, Haozhu Wang, Cheng Zhang, Parag B. Deotare, Amit K. Agrawal, Henri J. Lezec
Recent years have witnessed growing interest in the development of lasers with small footprint for their potential applications in small-volume sensing and on-chip optical communications. Surface-plasmons – electromagnetic modes evanescently confined to

Fabrication of Scanning Electrochemical Microscopy-Atomic Force Microscopy (SECM-AFM) Probes to Image Surface Topography and Reactivity at the Nanoscale

January 27, 2017
Author(s)
Jeyavel Velmurugan, Amit K. Agrawal, Sang M. An, Eric A. Choudhary, Veronika A. Szalai
Electrocatalysts, used in energy applications, rely on the solid-liquid interface to carry out productive chemistry. This interface is generally less amenable to standard surface-science characterization methods, making the investigation of the surface

Origins and Demonstrations of Electrons with Orbital Angular Momentum

January 9, 2017
Author(s)
Benjamin McMorran, Amit Agrawal, Peter Ercius, Vincenzo Grillo, Andrew Herzing, Tyler R. Harvey, Martin Linck
The surprising message of the 1992 paper of Allen, Beijersbergen, Spreeuw, and Woerdman (ABSW) was that photons could exhibit orbital motion in free space, which subsequently launched advancements in optical manipulation, microscopy, quantum optics

Steady State Vapor Bubble in Pool Boiling

February 3, 2016
Author(s)
An Zou, Ashish Chanana, Amit Agrawal, Peter C. Wayner, Jr., Shalabh C. Maroo
Boiling, a dynamic and multiscale process, has been studied for over five decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which involves nucleation, growth and departure, happens over a very

High-contrast and fast electrochromic switching enabled by plasmonics

January 27, 2016
Author(s)
Ting Xu, Erich C. Walter, Amit Agrawal, Christopher C. Bohn, Jeyavel Velmurugan, Wenqi Zhu, Henri Lezec, Albert A. Talin
With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the

Efficient diffractive phase optics for electrons

September 1, 2014
Author(s)
Tyler R. Harvey, Jordan S. Pierce, Amit Agrawal, Benjamin McMorran, Peter Ercius, Martin Linck
Electron diffraction gratings can be used to imprint well-defined phase structure onto an electron beam. For example, diffraction gratings have been used to prepare electron beams with unique phase dislocations, such as electron vortex beams, which hold

Design Considerations for Enhancing Absorption in Semiconductors on Metals with Surface Plasmon Polaritons

March 5, 2014
Author(s)
Christopher C. Bohn, Amit K. Agrawal, Youngmin Lee, Charles J. Choi, Matthew Davis, Paul M. Haney, Henri J. Lezec, Veronika A. Szalai
Surface plasmon polaritons have attracted attention for energy applications such as photovoltaic and photoelectrochemical cells because of their ability to improve optical absorption in thin fi lms. We show that surface plasmon polaritons enhance

All-angle negative refraction and active flat lensing of ultraviolet light

May 22, 2013
Author(s)
Ting Xu, Amit Agrawal, Maxim Abashin, Kenneth J. Chau, Henri Lezec
The ability of a left-handed medium to sustain backwards electromagnetic waves leads to counter-intuitive phenomena such as negative refraction. We report the experimental implementation of a three-dimensional negative-index metamaterial operating at an

Effect of Tin Doping on alpha-Fe2O3 Photoanodes for Water Splitting

June 28, 2012
Author(s)
Christopher C. Bohn, Amit Agrawal, Erich C. Walter, Mark D. Vaudin, Andrew Herzing, Paul M. Haney, Albert A. Talin, Veronika Szalai
Sputtered-deposited films of α-Fe2O3 of thickness 600 nm were investigated as photoanodes for solar water splitting and found to have photocurrents as high as 0.8 mA/cm2 at 1.23 V vs. the reversible hydrogen electrode (RHE). The incorporation of Sn into

An Efficient Large-Area Grating Coupler for Surface Plasmon Polaritons

June 1, 2012
Author(s)
Stefan T. Koev, Amit K. Agrawal, Henri J. Lezec, Vladimir A. Aksyuk
We report the design, fabrication and characterization of a periodic grating of shallow rectangular grooves in a metallic film with the goal of maximizing the coupling efficiency of an extended plane wave (PW) of visible or near-IR frequency light into a

Measuring domain sizes and compositional heterogeneities in P3HT-PCBM bulk heterojunction thin films with 1H spin diffusion NMR spectroscopy

March 21, 2012
Author(s)
Ryan C. Nieuwendaal, Hyun Wook Ro, David Germack, Regis J. Kline, Calvin Chan, Amit K. Agrawal, David J. Gundlach, David L. VanderHart, Dean M. DeLongchamp
In this manuscript we show that 1H spin diffusion NMR is a valuable method for estimating the domain sizes in thin films of a polymer-fullerene blend for bulk heterojunction (BHJ) photovoltaics. Variations in common BHJ film processing parameters have