Light scattering

About: Light scattering is a research topic. Over the lifetime, 37721 publications have been published within this topic receiving 861581 citations.

Flat optics: Controlling wavefronts with optical antenna metasurfaces

Abstract: Conventional optical components rely on the propagation effect to control the phase and polarization of light beams One can instead exploit abrupt phase and polarization changes associated with scattered light from optical resonators to control light propagation In this talk, we discuss the optical responses of anisotropic plasmonic antennas and a new class of planar optical components (“metasurfaces”) based on arrays of these antennas To demonstrate the versatility of metasurfaces, we show the design and experimental realization of a number of flat optical components: (a) metasurfaces with a constant interfacial phase gradient that deflect light into arbitrary directions; (b) metasurfaces with spiral phase distributions that create optical vortex beams of well-defined orbital angular momentum; (c) planar lenses and axicons that generate spherical wavefronts and non-diffracting Bessel beams, respectively; and (d) metasurfaces with anisotropic optical responses that create light beams of arbitrary polarization over a wide wavelength range

Light emitting device, display apparatus with an array of light emitting devices, and display apparatus method of manufacture

Abstract: A light emitting device and display apparatus using a plurality of light emitting devices can drastically reduce contrast loss due to light from an external source. The light emitting device has (a) light emitting chip(s) and a first layer covering the light emitting chip(s). A second layer including a light scattering material is provided at least over the first layer, and the surface of second layer has a plurality of protrusions which follow the topology of the light scattering material. The display apparatus is formed by disposing these light emitting devices in an array on a substrate.

Resonant light scattering spectroscopy of gold, silver and gold–silver alloy nanoparticles and optical detection in microfluidic channels

Abstract: Dark field resonant light scattering by gold and silver nanoparticles enables the detection and spectroscopy of such particles with high sensitivity, down to the single-particle level, and can be used to implement miniaturised optical detection schemes for chemical and biological analysis. Here, we present a straightforward optical spectroscopic methodology for the quantitative spectrometric study of resonant light scattering (RLS) by nanoparticles. RLS spectroscopy is complementary to UV-visible absorbance measurements, and we apply it to the characterisation and comparison of different types of gold, silver and gold-silver alloy nanoparticles. The potential of gold and silver particles as alternatives for fluorescent probes in certain applications is discussed. RLS spectroscopy is shown to be useful for studying analyte-induced gold nanoparticle assembly and nanoparticle chemistry, which can induce radical changes in the plasmonic resonances responsible for the strong light scattering. Furthermore, the feasibility of dark field RLS detection and quantitation of metal nanoparticles in microfluidic volumes is demonstrated, opening interesting possibilities for the further development of microfluidic detection schemes.

Mechanisms of Ultrasonic Modulation of Multiply Scattered Coherent Light

Abstract: An analytic model of the ultrasonic modulation of multiply scattered coherent light in scattering media is provided. The model is based on two mechanisms: the ultrasonic modulation of the index of refraction, which causes a modulation of the optical path lengths between consecutive scattering events, and the ultrasonic modulation of the displacements of Rayleigh scatterers, which causes a modulation of optical path lengths upon each scattering event. Multiply scattered light accumulates modulated optical path lengths along its path. Consequently, the intensity of the speckles that are formed by the multiply scattered light is modulated. In water solutions, for example, the contribution from the index of refraction is slightly less than the contribution from displacement when the scattering mean free path is less than a critical fraction of the acoustic wavelength, and it becomes increasingly greater than the contribution from displacement beyond this critical point.