The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

M. Kuester - One of the best experts on this subject based on the ideXlab platform.

  • IGARSS - Transformation of Solar Disc Radiances into a Top of the Atmosphere Radiance Source for On-Orbit Solar Calibration of Terrestrial Radiance Measurements
    2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006
    Co-Authors: D. Heath, A. Slaymaker, M. Kuester
    Abstract:

    Characteristics have been measured for a series of transmission optical devices that are considered for use in transforming solar disc radiances into a top of the atmosphere solar radiance source which can be used to calibrate terrestrial radiance measurements derived from orbiting remote sensing instruments. The types of transmission optical elements that were evaluated are a diffraction hole-plate, plates of fused silica and glass with ground surfaces, several types of microLens arrays and "engineered" diffusers. Collimated light from a diffuse source with approximately the angular solar diameter was imaged onto a CCD camera by a long focal length achromat at multiple narrow band wavelengths. The optical transform device was inserted into the beam of collimated radiation on the source side of the Achromatic Lens.

Nasser N Peyghambarian - One of the best experts on this subject based on the ideXlab platform.

  • adjustable hybrid diffractive refractive Achromatic Lens
    Optics Express, 2011
    Co-Authors: Pouria Valley, Nickolaos Savidis, Jim Schwiegerling, Mohammad Reza Dodge, Gholam A. Peyman, Nasser N Peyghambarian
    Abstract:

    We demonstrate a variable focal length Achromatic Lens that consists of a flat liquid crystal diffractive Lens and a pressure-controlled fluidic refractive Lens. The diffractive Lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive Lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive Lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive Lens’ focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive Lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats.

  • Adjustable hybrid diffractive/refractive Achromatic Lens
    Optics Express, 2011
    Co-Authors: Pouria Valley, Nickolaos Savidis, Jim Schwiegerling, Mohammad Reza Dodge, Gholam A. Peyman, Nasser N Peyghambarian
    Abstract:

    We demonstrate a variable focal length Achromatic Lens that consists of a flat liquid crystal diffractive Lens and a pressure-controlled fluidic refractive Lens. The diffractive Lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive Lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive Lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive Lens’ focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive Lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats.

W. Rudolph - One of the best experts on this subject based on the ideXlab platform.

  • Spatial and temporal transformation of femtosecond laser pulses by Lenses and Lens systems
    Journal of the Optical Society of America B, 1992
    Co-Authors: M. Kempe, Uwe Stamm, Bernd Wilhelmi, W. Rudolph
    Abstract:

    A Fourier-optical analysis of the transformation of ultrashort light pulses by Lenses is given. Inserting the material dispersion up to second order, we find a coupling between the temporal, spectral, and spatial properties of the light pulse. In general, this coupling leads to a drastic increase in pulse duration and width of the spatial intensity distribution in the focal plane of the Lens, which can be avoided with the use of Achromatic Lens doublets. The results are discussed for Gaussian-shaped input pulses.

D. Heath - One of the best experts on this subject based on the ideXlab platform.

  • IGARSS - Transformation of Solar Disc Radiances into a Top of the Atmosphere Radiance Source for On-Orbit Solar Calibration of Terrestrial Radiance Measurements
    2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006
    Co-Authors: D. Heath, A. Slaymaker, M. Kuester
    Abstract:

    Characteristics have been measured for a series of transmission optical devices that are considered for use in transforming solar disc radiances into a top of the atmosphere solar radiance source which can be used to calibrate terrestrial radiance measurements derived from orbiting remote sensing instruments. The types of transmission optical elements that were evaluated are a diffraction hole-plate, plates of fused silica and glass with ground surfaces, several types of microLens arrays and "engineered" diffusers. Collimated light from a diffuse source with approximately the angular solar diameter was imaged onto a CCD camera by a long focal length achromat at multiple narrow band wavelengths. The optical transform device was inserted into the beam of collimated radiation on the source side of the Achromatic Lens.

Pouria Valley - One of the best experts on this subject based on the ideXlab platform.

  • adjustable hybrid diffractive refractive Achromatic Lens
    Optics Express, 2011
    Co-Authors: Pouria Valley, Nickolaos Savidis, Jim Schwiegerling, Mohammad Reza Dodge, Gholam A. Peyman, Nasser N Peyghambarian
    Abstract:

    We demonstrate a variable focal length Achromatic Lens that consists of a flat liquid crystal diffractive Lens and a pressure-controlled fluidic refractive Lens. The diffractive Lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive Lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive Lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive Lens’ focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive Lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats.

  • Adjustable hybrid diffractive/refractive Achromatic Lens
    Optics Express, 2011
    Co-Authors: Pouria Valley, Nickolaos Savidis, Jim Schwiegerling, Mohammad Reza Dodge, Gholam A. Peyman, Nasser N Peyghambarian
    Abstract:

    We demonstrate a variable focal length Achromatic Lens that consists of a flat liquid crystal diffractive Lens and a pressure-controlled fluidic refractive Lens. The diffractive Lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive Lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive Lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive Lens’ focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive Lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats.