Behnood G. Ghamsari

  • Citations Per Year
Learn More
Surface polaritons, which are electromagnetic waves coupled to material charge oscillations, have enabled applications in concentrating, guiding and harvesting optical energy below the diffraction limit. Surface plasmon polaritons involve oscillations of electrons and are accessible in noble metals at visible and near-infrared wavelengths, whereas surface(More)
This work studies high-temperature superconducting spiral resonators as a viable candidate for realization of RF/microwave metamaterial atoms. The theory of superconducting spiral resonators will be discussed in detail, including the mechanism of resonance, the origin of higher order modes, the analytical framework for their determination, the effects of(More)
We have directly imaged the anisotropic nonlinear Meissner effect in an unconventional superconductor through the nonlinear electrodynamic response of both (bulk) gap nodes and (surface) Andreev bound states. A superconducting thin film is patterned into a compact self-resonant spiral structure, excited near resonance in the radio-frequency range, and(More)
Plasmonic antennas can enhance the intensity of a nanojoule laser pulse by localizing the electric field in their proximity. It has been proposed that the field can become strong enough to convert the fundamental laser frequency into high-order harmonics through an extremely nonlinear interaction with gas atoms that occupy the nanoscopic volume surrounding(More)
We have experimentally studied the dispersion of optical conductivity in few-layer graphene through reflection spectroscopy at visible wavelengths. A laser scanning microscope (LSM) with a supercontinuum laser source measured the frequency dependence of the reflectance of exfoliated graphene flakes, including monolayer, bilayer and trilayer graphene, loaded(More)
This paper demonstrates laser scanning microscopy (LSM) as a viable means for quantitative and accurate measurement of reflectivity of microscopic objects/samples with diffraction-limited spatial resolution. As an example, the LSM technique along with the quantized nature of reflectivity in graphene are utilized to identify and count the number of layers of(More)
We have experimentally studied the optical refractive index of few-layer graphene through reflection spectroscopy at visible wavelengths. A laser scanning microscope (LSM) with a coherent supercontinuum laser source measured the reflectivity of an exfoliated graphene flake on a Si/SiO2 substrate, containing monolayer, bilayer and trilayer areas, as the(More)
Alexander P. Zhuravel, B. G. Ghamsari, C. Kurter, P. Jung, S. Remillard, J. Abrahams, A. V. Lukashenko, Alexey V. Ustinov, and Steven M. Anlage 3 B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, UA-61103 Kharkov, Ukraine CNAM, Physics Department, University of Maryland, College Park, Maryland USA(More)
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the(More)
A localized and strong RF magnetic field, created by a magnetic write head, is used to examine the linear electrodynamic properties of a Nb superconducting film. The complex reflection coefficient of the write head held in close proximity to the films is measured as a function of sample temperature. A model combining a magnetic circuit (magnetic write head(More)