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  • Volume 45, Issue 9
  • Volume 45, Issue 9

    (Courtesy of University of California, Berkeley)
    Fragmentation of a sulfur fluoride (SF6) molecule (six fluorine atoms surrounding a central sulfur atom) is determined by the state of the electrons. After two electrons are ejected by an attosecond x-ray pulse (left), the molecule might fragment by shedding two fluorine atoms (right). The remaining electrons' state is changed by a 5 fs, 800 nm pulse. The field of the pulse rearranges electrons, altering the fragmentation and leading to different products, like neutral F2 molecules, for example.
    Fragmentation of a sulfur fluoride (SF6) molecule (six fluorine atoms surrounding a central sulfur atom) is determined by the state of the electrons. After two electrons are ejected by an attosecond x-ray pulse (left), the molecule might fragment by shedding two fluorine atoms (right). The remaining electrons' state is changed by a 5 fs, 800 nm pulse. The field of the pulse rearranges electrons, altering the fragmentation and leading to different products, like neutral F2 molecules, for example.
    Fragmentation of a sulfur fluoride (SF6) molecule (six fluorine atoms surrounding a central sulfur atom) is determined by the state of the electrons. After two electrons are ejected by an attosecond x-ray pulse (left), the molecule might fragment by shedding two fluorine atoms (right). The remaining electrons' state is changed by a 5 fs, 800 nm pulse. The field of the pulse rearranges electrons, altering the fragmentation and leading to different products, like neutral F2 molecules, for example.
    Fragmentation of a sulfur fluoride (SF6) molecule (six fluorine atoms surrounding a central sulfur atom) is determined by the state of the electrons. After two electrons are ejected by an attosecond x-ray pulse (left), the molecule might fragment by shedding two fluorine atoms (right). The remaining electrons' state is changed by a 5 fs, 800 nm pulse. The field of the pulse rearranges electrons, altering the fragmentation and leading to different products, like neutral F2 molecules, for example.
    Fragmentation of a sulfur fluoride (SF6) molecule (six fluorine atoms surrounding a central sulfur atom) is determined by the state of the electrons. After two electrons are ejected by an attosecond x-ray pulse (left), the molecule might fragment by shedding two fluorine atoms (right). The remaining electrons' state is changed by a 5 fs, 800 nm pulse. The field of the pulse rearranges electrons, altering the fragmentation and leading to different products, like neutral F2 molecules, for example.
    Research

    ADVANCED SPECTROSCOPY: Attosecond spectroscopy moves beyond the atomic scale

    Sept. 25, 2009
    Ultrashort attosecond light pulses, when used as the "shutter" in an imaging or spectroscopy system, can probe into the attosecond realm to see how the actual motions of electrons...
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    Research

    Laser propulsion powers next-generation aerospacecraft

    Sept. 1, 2009
    In contrast to the Space Elevator concept, in which high-power continuous-wave lasers beam light to photovoltaic cells attached to a vehicle that rides into space on a cable at...
    (Courtesy of Xceed)
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Research

    OPTICS FOR OPHTHALMOLOGY: Contact lenses have larger depth of focus

    Sept. 1, 2009
    A new type of contact lens created by researchers at Xceed Imaging (Petach-Tikva, Israel), Tel Aviv University (Tel Hashomer, Israel), and Bar-Ilan University (Ramat-Gan, Israel...
    Fiber Optics

    There is no free (free) lunch

    Sept. 1, 2009
    Airlines often use marginal pricing to sell empty seats. But for airline seats the marginal cost does not tend to zero dollars and hence the seats are never free.
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    Optics

    New Products

    Sept. 1, 2009
    LightTools 6.3 illumination design and analysis software adds an alternate optimization engine that supplements the existing optimizer and lets users address a broader range of...

    More content from Volume 45, Issue 9

    Research

    Molecular imaging gets a new tool

    Sept. 1, 2009
    In September of last year I happened to be in Europe on “beam day”–the day on which the Large Hadron Collider (LHC) was turned on for the first time.
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    Detectors & Imaging

    Manufacturers’ Product Showcase

    Sept. 1, 2009
    T-rad an incredibly sensitive Broad-band Pyroelectric Radiometer featuring DSP Lock In LabView Software.
    (Courtesy of Giorgio Adamo)
    A cross-sectional drawing shows electrons entering a light well (top) that consists of a hole passing through stacked metal and dielectric layers. The well is about 700 nm in diameter (bottom).
    A cross-sectional drawing shows electrons entering a light well (top) that consists of a hole passing through stacked metal and dielectric layers. The well is about 700 nm in diameter (bottom).
    A cross-sectional drawing shows electrons entering a light well (top) that consists of a hole passing through stacked metal and dielectric layers. The well is about 700 nm in diameter (bottom).
    A cross-sectional drawing shows electrons entering a light well (top) that consists of a hole passing through stacked metal and dielectric layers. The well is about 700 nm in diameter (bottom).
    A cross-sectional drawing shows electrons entering a light well (top) that consists of a hole passing through stacked metal and dielectric layers. The well is about 700 nm in diameter (bottom).
    Research

    NANOPHOTONICS: ‘Light well’ makes for unique tunable source

    Sept. 1, 2009
    An international team of researchers has demonstrated a tunable nanophotonic source based on free electrons passing through a metal/dielectric stack.
    Optics

    OPTICAL FABRICATION: Glass molding reduces cost of aspheres

    Sept. 1, 2009
    Thanks to the advent of precision glass molding–which enables the cost-effective manufacture of aspheric glass lenses–glass aspheres can now be incorporated in cost-conscious ...
    (Courtesy of VSL and TU Delft)
    A frequency-comb laser is the basis for an interferometric distance-measurement setup accurate to 25 µm over a 50 m distance.
    A frequency-comb laser is the basis for an interferometric distance-measurement setup accurate to 25 µm over a 50 m distance.
    A frequency-comb laser is the basis for an interferometric distance-measurement setup accurate to 25 µm over a 50 m distance.
    A frequency-comb laser is the basis for an interferometric distance-measurement setup accurate to 25 µm over a 50 m distance.
    A frequency-comb laser is the basis for an interferometric distance-measurement setup accurate to 25 µm over a 50 m distance.
    Test & Measurement

    METROLOGY: Frequency-comb laser measures long distances

    Sept. 1, 2009
    Interferometric methods are often used for long-distance measurements in air that require high accuracy.
    (Courtesy of ASU)
    Quantum-dot-based inks can be inkjet-printed to create arrays of red (left), green (center), and blue (right) LEDs (the diagrams at bottom indicate the LEDs’ colors on the CIE color-space chromaticity diagram).
    Quantum-dot-based inks can be inkjet-printed to create arrays of red (left), green (center), and blue (right) LEDs (the diagrams at bottom indicate the LEDs’ colors on the CIE color-space chromaticity diagram).
    Quantum-dot-based inks can be inkjet-printed to create arrays of red (left), green (center), and blue (right) LEDs (the diagrams at bottom indicate the LEDs’ colors on the CIE color-space chromaticity diagram).
    Quantum-dot-based inks can be inkjet-printed to create arrays of red (left), green (center), and blue (right) LEDs (the diagrams at bottom indicate the LEDs’ colors on the CIE color-space chromaticity diagram).
    Quantum-dot-based inks can be inkjet-printed to create arrays of red (left), green (center), and blue (right) LEDs (the diagrams at bottom indicate the LEDs’ colors on the CIE color-space chromaticity diagram).
    Research

    FLAT-PANEL DISPLAYS: QD display pixels are inkjet-printed

    Sept. 1, 2009
    Inkjet printing is so good at positioning and meting out the right quantity of material that it can be used not just for producing documents, but in industry as well–for example...
    (Courtesy of the University of Linz and Siemens)
    The shadow cast by illuminating a slide of a monarch butterfly with light at a 1310 nm wavelength was imaged with a QD-sensitized near-IR imager (top). The photosensitive layer consists of polymer materials and PbS QDs sandwiched with other materials to create a large-area imager (bottom left). The QDs are visible within the active layer (bottom right).
    The shadow cast by illuminating a slide of a monarch butterfly with light at a 1310 nm wavelength was imaged with a QD-sensitized near-IR imager (top). The photosensitive layer consists of polymer materials and PbS QDs sandwiched with other materials to create a large-area imager (bottom left). The QDs are visible within the active layer (bottom right).
    The shadow cast by illuminating a slide of a monarch butterfly with light at a 1310 nm wavelength was imaged with a QD-sensitized near-IR imager (top). The photosensitive layer consists of polymer materials and PbS QDs sandwiched with other materials to create a large-area imager (bottom left). The QDs are visible within the active layer (bottom right).
    The shadow cast by illuminating a slide of a monarch butterfly with light at a 1310 nm wavelength was imaged with a QD-sensitized near-IR imager (top). The photosensitive layer consists of polymer materials and PbS QDs sandwiched with other materials to create a large-area imager (bottom left). The QDs are visible within the active layer (bottom right).
    The shadow cast by illuminating a slide of a monarch butterfly with light at a 1310 nm wavelength was imaged with a QD-sensitized near-IR imager (top). The photosensitive layer consists of polymer materials and PbS QDs sandwiched with other materials to create a large-area imager (bottom left). The QDs are visible within the active layer (bottom right).
    Detectors & Imaging

    DETECTORS: Near-IR imager uses quantum-dot-sensitized photodiodes

    Sept. 1, 2009
    Indium gallium arsenide (InGaAs) photodiodes and quantum-well IR photodetectors are typical methods of choice for near-IR detection and imaging applications in the spectral region...
    Each pixel defined by the filter array combines the four narrow bands, expressed by central wavelengths 1 2 3 4; in addition, each covers 16 pixels on the monochromic CMOS sensor (left). Within the useful pixel region (considering the overlapping areas among the filters), the hue value for each wavelength of a new pixel is calculated by averaging the color value of the area in red (right).
    Each pixel defined by the filter array combines the four narrow bands, expressed by central wavelengths 1 2 3 4; in addition, each covers 16 pixels on the monochromic CMOS sensor (left). Within the useful pixel region (considering the overlapping areas among the filters), the hue value for each wavelength of a new pixel is calculated by averaging the color value of the area in red (right).
    Each pixel defined by the filter array combines the four narrow bands, expressed by central wavelengths 1 2 3 4; in addition, each covers 16 pixels on the monochromic CMOS sensor (left). Within the useful pixel region (considering the overlapping areas among the filters), the hue value for each wavelength of a new pixel is calculated by averaging the color value of the area in red (right).
    Each pixel defined by the filter array combines the four narrow bands, expressed by central wavelengths 1 2 3 4; in addition, each covers 16 pixels on the monochromic CMOS sensor (left). Within the useful pixel region (considering the overlapping areas among the filters), the hue value for each wavelength of a new pixel is calculated by averaging the color value of the area in red (right).
    Each pixel defined by the filter array combines the four narrow bands, expressed by central wavelengths 1 2 3 4; in addition, each covers 16 pixels on the monochromic CMOS sensor (left). Within the useful pixel region (considering the overlapping areas among the filters), the hue value for each wavelength of a new pixel is calculated by averaging the color value of the area in red (right).
    Detectors & Imaging

    MEDICAL IMAGING: Real-time multispectral imager promises portable diagnosis

    Sept. 1, 2009
    A miniaturized sensor developed at the Georgia Institute of Technology, which is claimed to be the first such device able to produce narrowband multispectral imagery in real time...
    (Courtesy of Emcore)
    FIGURE 1. An integrated frequency-domain terahertz source and detector module uses dual lasers.
    FIGURE 1. An integrated frequency-domain terahertz source and detector module uses dual lasers.
    FIGURE 1. An integrated frequency-domain terahertz source and detector module uses dual lasers.
    FIGURE 1. An integrated frequency-domain terahertz source and detector module uses dual lasers.
    FIGURE 1. An integrated frequency-domain terahertz source and detector module uses dual lasers.
    Detectors & Imaging

    TERAHERTZ SOURCES: Photonic integration improves heterodyne photomixing terahertz sources

    Sept. 1, 2009
    Single-package hybrid optical integration of two semiconductor laser chips with a high-resolution wavelength discriminator has been used to realize a tunable terahertz source ...
    Electroluminescence (EL) spectra of LED A and LED B show that the addition of a layer of concave plastic microlenses onto the LEDs greatly boosts light output.
    Electroluminescence (EL) spectra of LED A and LED B show that the addition of a layer of concave plastic microlenses onto the LEDs greatly boosts light output.
    Electroluminescence (EL) spectra of LED A and LED B show that the addition of a layer of concave plastic microlenses onto the LEDs greatly boosts light output.
    Electroluminescence (EL) spectra of LED A and LED B show that the addition of a layer of concave plastic microlenses onto the LEDs greatly boosts light output.
    Electroluminescence (EL) spectra of LED A and LED B show that the addition of a layer of concave plastic microlenses onto the LEDs greatly boosts light output.
    Lasers & Sources

    MICRO-OPTICS: Concave microlenses boost LED output

    Sept. 1, 2009
    Semiconductors that make up an LED have such a high refractive index that much of the light produced by a conventional LED never escapes from the device into the surrounding air...
    (Courtesy of Xceed)
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Modulation-transfer-function (MTF) simulations for a 3-mm-diameter eye pupil compare far-field results (dashed curves) and near-field results (solid curves) with no change in eye-lens focus. A contact lens with the EDOF pattern at a spatial frequency of 30 cycles/mm shows good imaging for both near and far field (top); without the EDOF pattern at the same frequency, far-field imaging is poor (center). An MTF chart shows that near- and far-field imaging results are almost identical (bottom).
    Optics

    OPTICS FOR OPHTHALMOLOGY: Contact lenses have larger depth of focus

    Sept. 1, 2009
    A new type of contact lens created by researchers at Xceed Imaging (Petach-Tikva, Israel), Tel Aviv University (Tel Hashomer, Israel), and Bar-Ilan University (Ramat-Gan, Israel...
    FIGURE 1. Traditional PIN APD devices (left) don’t measure up to SAM-APD devices (right), whose gain enhancement is made possible through the use of the separate absorption and multiplication (SAM) regime.
    FIGURE 1. Traditional PIN APD devices (left) don’t measure up to SAM-APD devices (right), whose gain enhancement is made possible through the use of the separate absorption and multiplication (SAM) regime.
    FIGURE 1. Traditional PIN APD devices (left) don’t measure up to SAM-APD devices (right), whose gain enhancement is made possible through the use of the separate absorption and multiplication (SAM) regime.
    FIGURE 1. Traditional PIN APD devices (left) don’t measure up to SAM-APD devices (right), whose gain enhancement is made possible through the use of the separate absorption and multiplication (SAM) regime.
    FIGURE 1. Traditional PIN APD devices (left) don’t measure up to SAM-APD devices (right), whose gain enhancement is made possible through the use of the separate absorption and multiplication (SAM) regime.
    Detectors & Imaging

    ULTRAVIOLET DETECTORS: Nitrides push performance of UV photodiodes

    Sept. 1, 2009
    Nitrides offer considerable advantages over other materials for ultraviolet detection. Recently, they proved useful for creating the world’s first UV single-photon detectors with...
    (Courtesy of Purdue University)
    FIGURE 1. A finite-element simulation depicts an extraordinary wave with a wavelength of 350 nm, which is incident from the left onto a metallic mask of thickness 30 nm containing a double slit with 5 nm slits and a 35 nm center-to-center distance. The electric-field amplitude is shown for two cases: a 100 nm silver/silica (Ag/SiO2) bulk anisotropic slab (left) and a ten-layer Ag/SiO2 stack with each layer 10 nm thick (right). The bulk anisotropic slab has a filling fraction of 0.5 (equal volumes of Ag and SiO2).
    FIGURE 1. A finite-element simulation depicts an extraordinary wave with a wavelength of 350 nm, which is incident from the left onto a metallic mask of thickness 30 nm containing a double slit with 5 nm slits and a 35 nm center-to-center distance. The electric-field amplitude is shown for two cases: a 100 nm silver/silica (Ag/SiO2) bulk anisotropic slab (left) and a ten-layer Ag/SiO2 stack with each layer 10 nm thick (right). The bulk anisotropic slab has a filling fraction of 0.5 (equal volumes of Ag and SiO2).
    FIGURE 1. A finite-element simulation depicts an extraordinary wave with a wavelength of 350 nm, which is incident from the left onto a metallic mask of thickness 30 nm containing a double slit with 5 nm slits and a 35 nm center-to-center distance. The electric-field amplitude is shown for two cases: a 100 nm silver/silica (Ag/SiO2) bulk anisotropic slab (left) and a ten-layer Ag/SiO2 stack with each layer 10 nm thick (right). The bulk anisotropic slab has a filling fraction of 0.5 (equal volumes of Ag and SiO2).
    FIGURE 1. A finite-element simulation depicts an extraordinary wave with a wavelength of 350 nm, which is incident from the left onto a metallic mask of thickness 30 nm containing a double slit with 5 nm slits and a 35 nm center-to-center distance. The electric-field amplitude is shown for two cases: a 100 nm silver/silica (Ag/SiO2) bulk anisotropic slab (left) and a ten-layer Ag/SiO2 stack with each layer 10 nm thick (right). The bulk anisotropic slab has a filling fraction of 0.5 (equal volumes of Ag and SiO2).
    FIGURE 1. A finite-element simulation depicts an extraordinary wave with a wavelength of 350 nm, which is incident from the left onto a metallic mask of thickness 30 nm containing a double slit with 5 nm slits and a 35 nm center-to-center distance. The electric-field amplitude is shown for two cases: a 100 nm silver/silica (Ag/SiO2) bulk anisotropic slab (left) and a ten-layer Ag/SiO2 stack with each layer 10 nm thick (right). The bulk anisotropic slab has a filling fraction of 0.5 (equal volumes of Ag and SiO2).
    Optics

    NANOIMAGING: Bilayer metamaterial lens breaks the diffraction limit

    Sept. 1, 2009
    The quest for subwavelength imaging through anisotropic metamaterials has produced a design for a bilayer lens that can restore a nearly perfect image.
    (Courtesy of Brad Plummer/SLAC)
    Quadrupole focusing magnets between each of 33 undulators guide the electron pulses through the Linac Coherent Light Source.
    Quadrupole focusing magnets between each of 33 undulators guide the electron pulses through the Linac Coherent Light Source.
    Quadrupole focusing magnets between each of 33 undulators guide the electron pulses through the Linac Coherent Light Source.
    Quadrupole focusing magnets between each of 33 undulators guide the electron pulses through the Linac Coherent Light Source.
    Quadrupole focusing magnets between each of 33 undulators guide the electron pulses through the Linac Coherent Light Source.
    Detectors & Imaging

    PHOTONIC FRONTIERS: FREE-ELECTRON LASERS: Hard-x-ray free-electron laser is major milestone for researchers

    Sept. 1, 2009
    Scientists now have access to the world’s most brilliant source of hard x-rays at the Linac Coherent Light Source.
    Research

    When peeled, adhesive tape emits terahertz radiation

    Sept. 1, 2009
    Believe it or not, researchers at the University of Wollongong (New South Wales, Australia) have discovered that peeling adhesive tape emits unpolarized terahertz radiation.