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Photonic crystal
About: Photonic crystal is a research topic. Over the lifetime, 43424 publications have been published within this topic receiving 887083 citations.
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16 May 2010
TL;DR: The effect may be demonstrated in a Si slab illuminated in the 500–900nm range and form a novel class of linear optical elements—absorptive interferometers—which may be useful for controlled optical energy transfer.
Abstract: An arbitrary body or aggregate can be made perfectly absorbing at discrete frequencies, if a precise amount of dissipation is added under specific conditions of coherent monochromatic illumination. This effect arises from the interaction of optical absorption and wave interference, and corresponds to moving a zero of the S-matrix onto the real wavevector axis. It is thus the time-reversed process of lasing at threshold. The effect may be demonstrated in a Si slab illuminated in the 500–900nm range. Coherent perfect absorbers form a novel class of linear optical elements—absorptive interferometers—which may be useful for controlled optical energy transfer.
991 citations
TL;DR: A bilayer of materials for which not all of the principal elements of the permeability and permittivity tensors have the same sign can transfer a field distribution from one side to the other, including near fields, without requiring internal exponentially growing waves.
Abstract: The range of available electromagnetic material properties has been broadened by recent developments in structured media, notably photonic band gap materials and metamaterials. These media have allowed the realization of solutions to Maxwell’s equations not available in naturally occurring materials, fueling the discovery of new physical phenomena and the development of devices. Photonic crystal effects typically occur when the wavelength is on the same order or smaller than the lattice constant of the crystal. Metamaterials, on the other hand, have unit cell dimensions much smaller than the wavelength of interest. A homogenization process, not unlike
987 citations
TL;DR: In this paper, the authors measured microcavity resonances in two-and three-dimensional photonic-bandgap (PBG) structures integrated directly into a sub-micrometre-scale silicon waveguide.
Abstract: Confinement of light to small volumes has important implications for optical emission properties: it changes the probability of spontaneous emission from atoms, allowing both enhancement and inhibition. In photonic-bandgap (PBG) materials1,2,3,4 (also known as photonic crystals), light can be confined within a volume of the order of (λ/2n)3, where λ is the emission wavelength and n the refractive index of the material, by scattering from a periodic array of scattering centres. Until recently5,6, the properties of two- and three-dimensional PBG structures have been measured only at microwave frequencies. Because the optical bandgap scales with the period of the scattering centres, feature sizes of around 100 nm are needed for manipulation of light at the infrared wavelength (1.54 µm) used for optical communications. Fabricating features this small requires the use of electron-beam or X-ray lithography. Here we report measurements of microcavity resonances in PBG structures integrated directly into a sub-micrometre-scale silicon waveguide. The microcavity has a resonance at a wavelength of 1.56 µm, a quality factor of 265 and a modal volume of 0.055 µm3. This level of integration might lead to new photonic chip architectures and devices, such as zero-threshold microlasers, filters and signal routers.
979 citations
TL;DR: In this paper, the authors reported on stimulated Raman scattering in an approximately 1-meter-long hollow-core photonic crystal fiber filled with hydrogen gas under pressure, which was guided and confined in the 15-micrometer-diameter hollow core by a two-dimensional photonic bandgap.
Abstract: We report on stimulated Raman scattering in an approximately 1-meter-long hollow-core photonic crystal fiber filled with hydrogen gas under pressure. Light was guided and confined in the 15-micrometer-diameter hollow core by a two-dimensional photonic bandgap. Using a pulsed laser source (pulse duration, 6 nanoseconds; wavelength, 532 nanometers), the threshold for Stokes (longer wavelength) generation was observed at pulse energies as low as 800 ± 200 nanojoules, followed by a coherent anti-Stokes (shorter wavelength) generation threshold at 3.4 ± 0.7 microjoules. The pump-to-Stokes conversion efficiency was 30 ± 3% at a pulse energy of only 4.5 microjoules. These energies are almost two orders of magnitude lower than any other reported energy, moving gas-based nonlinear optics to previously inaccessible parameter regimes of high intensity and long interaction length.
961 citations
TL;DR: In this paper, the authors describe the recent experimental progress in the control of spontaneous emission by manipulating optical modes with photonic crystals, which can contribute to the evolution of a variety of applications, including illumination, display, optical communication, solar energy and even quantum information systems.
Abstract: We describe the recent experimental progress in the control of spontaneous emission by manipulating optical modes with photonic crystals. It has been clearly demonstrated that the spontaneous emission from light emitters embedded in photonic crystals can be suppressed by the so-called photonic bandgap, whereas the emission efficiency in the direction where optical modes exist can be enhanced. Also, when an artificial defect is introduced into the photonic crystal, a photonic nanocavity is produced that can interact with light emitters. Cavity quality factors, or Q factors, of up to 2 million have been realized while maintaining very small mode volumes, and both spontaneous-emission modification (the Purcell effect) and strong-coupling phenomena have been demonstrated. The use of photonic crystals and nanocavities to manipulate spontaneous emission will contribute to the evolution of a variety of applications, including illumination, display, optical communication, solar energy and even quantum-information systems.
936 citations