Presentations

    2D impedance-matched zero-index metamaterial, at SPIE Photonics West: Photonic and Phononic Properties of Engineered Nanostructures IV (San Francisco, California), Wednesday, February 5, 2014
    Recent efforts to achieve metamaterials with a vanishing refractive index take advantage of the low index at a photonic band edge. This behavior is accompanied by a divergent impedance, resulting in inefficient transmission. We investigate the nature of this discontinuity and show that it can be removed by tuning the electric and magnetic response of the metamaterial. We present a design for a 2D zero-index metamaterial based on this concept. The metamaterial is entirely dielectric, which results in low-loss transmission at the design wavelength of 1.55um. This behavior is confirmed using... Read more about 2D impedance-matched zero-index metamaterial
    Less is More: Extreme Optics with Zero Refractive Index, at United States Coast Guard Academy (New London, Connecticut), Monday, October 26, 2015:
    Nanotechnology has enabled the development of nanostructured composite materials (metamaterials) with exotic optical properties not found in nature. In the most extreme case, we can create materials which support light waves that propagate with infinite phase velocity, corresponding to a refractive index of zero. This zero index can only be achieved by simultaneously controlling the electric and magnetic resonances of the nanostructure. We present an in-plane metamaterial design consisting of silicon pillar arrays, embedded within a polymer matrix and sandwiched between gold layers. Using an... Read more about Less is More: Extreme Optics with Zero Refractive Index
    Less is More: Extreme Optics with Zero Refractive Index, at Photonics West 2016, Integrated Optics: Devices, Materials, and Technologies XX (San Francisco, CA), Monday, February 15, 2016:
    Nanotechnology has enabled the development of nanostructured composite materials (metamaterials) with exotic optical properties not found in nature. In the most extreme case, we can create materials which support light waves that propagate with infinite phase velocity, corresponding to a refractive index of zero. This zero index can only be achieved by simultaneously controlling the electric and magnetic resonances of the nanostructure. We present an in-plane metamaterial design consisting of silicon pillar arrays, embedded within a polymer matrix and sandwiched between gold layers. Using an... Read more about Less is More: Extreme Optics with Zero Refractive Index
    Inverse Transformation Optics with Realistic Material Parameters, at META'15 (New York, New York), Thursday, June 4, 2015:
    We present a method to generate transformation functions based on a space of achievable material properties. To validate this approach, we consider the range of effective refractive index achievable using silver nanowires in a dielectric background. Given fabrication constraints, we generate a reduced cloaking transformation and confirm its performance using FDTD and FEM simulations. We explore conditions for finding appropriate mappings in restricted parameter spaces, and strategies for optimizing transformations to account for absorption and scattering.
    Zero-index waveguides for metasurface applications, at 2015 MRS Fall Meeting (Boston, Massachusetts), Wednesday, December 2, 2015:
    Metamaterials with a refractive index of zero have emerged as a new tool for phase control in nanophotonics. Waves propagate within such metamaterials with infinite phase velocity, resulting in uniform phase throughout. Recently two-dimensional zero-index metamaterials have been integrated with on-chip silicon photonics, allowing for phase-free propagation over large areas. However, zero-index modes are inherently lossy: since the momentum of the wave is zero, it lies above the light line, and therefore couples to waves in free space. In particular, momentum conservation implies that the... Read more about Zero-index waveguides for metasurface applications