physics

Black silicon, at Institute for Atomic and Molecular Science, Academia Sinica (Taipei, Taiwan), Friday, January 29, 2016:
Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The resulting textured surface is highly absorbing and looks black to the eye. The properties of this 'black silicon' make it useful for a wide range of commercial devices. In particular, we have been able to fabricate highly-sensitive PIN photodetectors using this material. The sensitivity extends to wavelengths of 1600 nm making them particularly useful for applications in communications and remote sensing.
Less is More: Extreme Optics with Zero Refractive Index, at Faculty of Physics Pontificia Universidad Católica de Chile (Santiago, Chile), Tuesday, January 12, 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
Wrapping light around a hair, at Sichuan University (Chengdu, China), Tuesday, December 22, 2015:
Can light be guided by a fiber whose diameter is much smaller than the wavelength of the light? Can we mold the flow of light on the micrometer scale so it wraps, say, around a hair? Until recently the answer to these questions was "no". We developed a technique for drawing long, free-standing silica wires with diameters down to 50 nm that have a surface smoothness at the atomic level and a high uniformity of diameter. Light can be launched into these silica nanowires by optical evanescent coupling and the wires allow low-loss single-mode operation. They can be bent sharply, making it... Read more about Wrapping light around a hair
Less is More: Extreme Optics with Zero Refractive Index, at Sichuan University (Chengdu, China), Monday, December 21, 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 Sichuan University (Chengdu, China), Saturday, December 19, 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
On-chip zero-index metamaterialse, at Peking University (Beijing, China), Friday, December 18, 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 On-chip zero-index metamaterialse
Less is More: Extreme Optics with Zero Refractive Index, at Wednesday Night Research Seminar, Harvard University (Cambridge, MA), Wednesday, December 2, 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
Nonlinear Phase-Matching in 2D Integrated Zero-Index Metamaterials, at MRS: Optical Metamaterials - From New Plasmonic Materials to Metasurface Devices (Boston, MA), Wednesday, December 2, 2015:
Nonlinear optics play an important role in many applications in photonics and quantum optics, such as in frequency conversion, sensing, and entangled-photon generation. The strong field confinement obtained by the transition to an integrated platform has led to unprecedented nonlinear figures of merit and the miniaturization of nonlinear devices. However, phase-matching remains an essential component to nonlinear processes and represents a significant obstacle, with many different free-space and on-chip techniques being developed to circumvent its constraints. Recently, a 1-dimensional... Read more about Nonlinear Phase-Matching in 2D Integrated Zero-Index Metamaterials
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
Nonlinear optics in on-chip zero-index metamaterials, at Engineering Physics seminar, Universite de Montreal (Montreal, QC, Canada), Monday, November 23, 2015:
Optical metamaterials - composite materials whose electromagnetic properties are finely engineered by designing their constituents - have been shown to exhibit strange and exotic properties, such as negligible or negative indices of refraction and the direct control of the amplitude and phase of light. These properties have been used for innumerable applications, such as flat lenses, invisibility cloaks as well as previously unseen nonlinear interactions. Recently, our group has demonstrated the first on-chip metamaterial with a refractive index of zero. These isotropic structures exhibit a... Read more about Nonlinear optics in on-chip zero-index metamaterials

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