Zahyun Ku

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In order to more clearly observe the bianisotropic effects due to fabrication-induced structural asymmetries in negative-index metamaterials based on a fishnet structure, it is necessary to measure the optical properties with symmetric substrate and superstrate bounding layers. This is accomplished in this report using an index-matching fluid and identical(More)
Interferometric lithography (IL) is a powerful technique for the definition of large-area, nanometer-scale, periodically patterned structures. Patterns are recorded in a light-sensitive medium, such as a photoresist, that responds nonlinearly to the intensity distribution associated with the interference of two or more coherent beams of light. The(More)
We demonstrate a nanoscale, subpicosecond (ps) metamaterial device capable of terabit/second all-optical communication in the near-IR. The 600 fs response, 2 orders of magnitude faster than previously reported, is achieved by accessing a previously unused regime of high-injection level, subpicosecond carrier dynamics in the alpha-Si dielectric layer of the(More)
In the past few years, there has been increasing interest in surface plasmon-polaritons, as a result of the strong near-field enhancement of the electric fields at a metal-dielectric interface. Here we show the first demonstration of a monolithically integrated plasmonic focal plane array (FPA) in the mid-infrared region, using a metal with a(More)
Negative-index metamaterials (NIMs) at near infrared wavelengths (~2 mum) are fabricated with circular, elliptical and rectangular holes penetrating through metal/dielectric/metal films. All three NIM structures exhibit similar figures of merit; however, the transmission is higher for the NIM with rectangular holes as a result of an improved impedance match(More)
The effect of a nonzero sidewall angle on the performance of multiple layer fishnet-structure ͑one to three functional layers͒ negative index metamaterials is evaluated experimentally. The fabrication-induced sidewall angle results in a bianisotropy ͑inhomogeneous asymmetry͒ that is significant at optical frequencies. Good agreement is obtained between the(More)
Simulation results of near infrared (100- to 200-THz) fishnet-structure negative-index metamaterials (NIMs) with single and multiple functional layers exhibit bi-anisotropy - inhomogeneous asymmetry - due to the presence of a sidewall-angle. The influence of sidewall-angle resulting from realistic fabrication processes is investigated through the retrieved(More)
This article reports a simple, versatile approach to the fabrication of lithographically defined mesoscopic colloidal silica nanoparticle patterns over large areas using spin-coating, interferometric lithography, and reactive-ion etching. One-dimensional nanoparticle films (bands) and 2D discs, diamonds, and holes with sub-micrometer periodicity, high(More)
Over the years, there has been increasing interest in the integration of metal hole array (MHA) with optoelectronic devices, as a result of enhanced coupling of incident light into the active layer of devices via surface plasmon polariton (SPP) resonances. However, not all incident light contributes to the SPP resonances due to significant reflection loss(More)
In our previous theoretical study, we performed target detection using a plasmonic sensor array incorporating the data-processing technique termed "algorithmic spectrometry". We achieved the reconstruction of a target spectrum by extracting intensity at multiple wavelengths with high resolution from the image data obtained from the plasmonic array. The(More)