scholarly journals Development of a large area InGaAs APD receiver based on an impact ionization engineered detector for free-space lasercomm applications

2012 ◽  
Author(s):  
H. R. Burris ◽  
M. S. Ferraro ◽  
W. T. Freeman ◽  
C. I. Moore ◽  
J. L. Murphy ◽  
...  
Keyword(s):  
Free Space ◽  
Impact Ionization ◽  
Large Area

scholarly journals In-Situ Exploration of Dust in the Solar System and Initial Results from the Galileo Dust Detector

1991 ◽  
Vol 126 ◽  
pp. 21-28
Author(s):  
E. Grün ◽  
H. Fechtig ◽  
M. S. Hanner ◽  
J. Kissel ◽  
B.-A. Lindblad ◽  
...  
Keyword(s):  
Solar System ◽  
Impact Ionization ◽  
Interplanetary Space ◽  
Interplanetary Dust ◽  
High Mass ◽  
Large Area ◽  
Dust Flux ◽  
Highly Sensitive ◽  
Low Mass

AbstractIn-situ measurements of interplanetary dust have been performed in the heliocentric distance range from 0.3 AU out to 18 AU. Due to their small sensitive areas (typically 0.01 m2for the highly sensitive impact ionization sensors) or low mass sensitivities (≥10−9g of the large area penetration detectors) previous instruments recorded only a few 100 impacts during their lifetimes. Nevertheless, important information on the distribution of dust in interplanetary space has been obtained between 0.3 and 18 AU distance from the Sun. The Galileo dust detector combines the high mass sensitivity of impact ionization detectors (10−15g) together with a large sensitive area (0.1 m2). The Galileo spacecraft was launched on October 18, 1989 and is on its solar system cruise towards Jupiter. Initial measurements of the dust flux from 0.7 to 1.2 AU are presented.

scholarly journals Novel Multiband Metal-Rimmed Antenna for Wearable Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Liu ◽  
Jianghong Han ◽  
Songhua Hu ◽  
Li Zhang
Keyword(s):  
Numerical Simulations ◽  
Human Body ◽  
Free Space ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Ground Plane ◽  
Large Area ◽  
Specific Absorption ◽  
Additional Resonance ◽  
Feeding Structure

A novel multiband antenna with an unbroken metal rim for wearable applications is presented. In order to achieve a wideband behavior, minimizing at the same time the size of the clearance area on the antenna ground plane, a novel feeding structure is proposed. This is achieved by connecting the metal rim to the ground plane thus allowing generating one lower-frequency resonance without occupying a large area. An additional resonance is then obtained using a suitable shorting patch. In this way, the proposed antenna presents a broadband behavior, while the width of the clearance area on the ground plane is of only 2 mm. The antenna performances in free-space and on a human phantom simulating a human body are analyzed by means of numerical simulations. Finally, the specific absorption rate (SAR) is analyzed to establish the antenna reliability in wearable applications. The experimental results demonstrate superior and stable performances of the metal-rimmed antenna when it is employed in wearable applications.

Impact ionization engineered avalanche photodiode arrays for free space optical communication

2016 ◽  
Author(s):  
Mike S. Ferraro ◽  
William S. Rabinovich ◽  
William R. Clark ◽  
William D. Waters ◽  
Joe C. Campbell ◽  
...  
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Impact Ionization ◽  
Avalanche Photodiode ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Space Optical Communication ◽  
Photodiode Arrays

scholarly journals Increasing the Link‐distance of Free‐space Quantum Coherent Communication with Large Area Detectors

2021 ◽  
Vol 2 (1) ◽  
pp. 1-7
Author(s):  
Rupesh Kumar ◽  
Igor Konieczniak ◽  
Gerald Bonner ◽  
Tim Spiller
Keyword(s):  
Free Space ◽  
Large Area ◽  
Link Distance ◽  
Coherent Communication

scholarly journals Free-space terahertz radiation from a LT-GaAs-on-quartz large-area photoconductive emitter

2016 ◽  
Vol 24 (23) ◽  
pp. 26986 ◽  
Author(s):  
David R. Bacon ◽  
Andrew D. Burnett ◽  
Matthew Swithenbank ◽  
Christopher Russell ◽  
Lianhe Li ◽  
...  
Keyword(s):  
Terahertz Radiation ◽  
Free Space ◽  
Large Area ◽  
Photoconductive Emitter ◽  
Lt Gaas

Large area adaptive avalanche photodetector arrays for free-space optical communication

2008 ◽  
Author(s):  
Mike S. Ferraro ◽  
Wade T. Freeman ◽  
Rita Mahon ◽  
James L. Murphy ◽  
Peter G. Goetz ◽  
...  
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Large Area ◽  
Space Optical Communication ◽  
Photodetector Arrays

Impact-ionization-engineered avalanche photodiode arrays for free-space optical communication

2016 ◽  
Vol 55 (11) ◽  
pp. 111609 ◽  
Author(s):  
Mike S. Ferraro ◽  
William S. Rabinovich ◽  
William R. Clark ◽  
William D. Waters ◽  
Joe C. Campbell ◽  
...  
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Impact Ionization ◽  
Avalanche Photodiode ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Space Optical Communication ◽  
Photodiode Arrays

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

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