Results 211 to 220 of about 17,852 (256)
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Beam profiling monitors beam shaping
SPIE Proceedings, 2005Evaluating the success of beam shaping techniques requires the measurement of the resulting beam profile. Laser beam profilers have been used extensively throughout the laser industry to enable users to evaluate the "quality" of their laser beam. Profilers have made many strides in recent technology, including new cameras, new beam sampling optics, new
Carlos B. Roundy, Larry Green
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Radiology, 1974
A flexible lead chain has been designed for the shaping of irregular fields, primarily to achieve skin-sparing at the field edge. The device is simple and easy to use, allows better conformity to the desired contour than is usually achieved with standardized blocks, and avoids gaps in the shielding.
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A flexible lead chain has been designed for the shaping of irregular fields, primarily to achieve skin-sparing at the field edge. The device is simple and easy to use, allows better conformity to the desired contour than is usually achieved with standardized blocks, and avoids gaps in the shielding.
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Applied Optics, 1995
Several options for beam-shaping optics are presented, among them a novel single-element solution with toroidal surfaces in which the far-field angular spread of the outgoing beam is the average of the incoming divergences. The beam-shaping elements are judged with respect to their positioning and fabrication tolerances.
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Several options for beam-shaping optics are presented, among them a novel single-element solution with toroidal surfaces in which the far-field angular spread of the outgoing beam is the average of the incoming divergences. The beam-shaping elements are judged with respect to their positioning and fabrication tolerances.
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Medical Dosimetry, 1998
Field shaping for stereotactic radiosurgery and stereotactic radiotherapy has evolved from static field shaping techniques applied to static or arc fields and now includes dynamic field shaping definition which can be dynamically modified during the arc.
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Field shaping for stereotactic radiosurgery and stereotactic radiotherapy has evolved from static field shaping techniques applied to static or arc fields and now includes dynamic field shaping definition which can be dynamically modified during the arc.
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AIP Conference Proceedings, 2008
We consider the promising properties of very simple Diffractive Optical Elements (DOE) for reshaping the intensity profile of a laser beam. The first type of DOE that we have considered is a phase aperture which consists in a transparent plate with a circular relief introducing a π phase shift in the central region of the incident beam.
Kamel Aït-Ameur +6 more
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We consider the promising properties of very simple Diffractive Optical Elements (DOE) for reshaping the intensity profile of a laser beam. The first type of DOE that we have considered is a phase aperture which consists in a transparent plate with a circular relief introducing a π phase shift in the central region of the incident beam.
Kamel Aït-Ameur +6 more
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SPIE Proceedings, 2014
Many commercial laser systems deliver a beam having a Gaussian intensity profile, however, numerous applications require other intensity profiles (top-hat, hollow beam, Bessel beam,…) which are in general obtained by converting the standard Gaussian beam (GB) through transparent diffractive optical elements (DOE). Laser beam shaping (LBS) by use of DOE’
A. Harfouche +3 more
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Many commercial laser systems deliver a beam having a Gaussian intensity profile, however, numerous applications require other intensity profiles (top-hat, hollow beam, Bessel beam,…) which are in general obtained by converting the standard Gaussian beam (GB) through transparent diffractive optical elements (DOE). Laser beam shaping (LBS) by use of DOE’
A. Harfouche +3 more
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Robotic Radiosurgery with Beams of Adaptable Shapes
1995In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of fixed cross-section. The radiation source can only be moved along simple standardized paths. A new radiosurgical system based on a six degree-of-freedom robotic arm has been developed to overcome
Achim Schweikard +2 more
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On the Theory of Antenna Beam Shaping
Journal of Applied Physics, 1952The diffraction pattern of an aperture with amplitude distribution A(x) and phase function ψ(x) is examined for two cases: (1) controlled variation of the amplitude distribution with known uniform phase; (2) controlled variation of phase with known amplitude distribution.
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SPIE Proceedings, 1991
A novel optical system is described which can be used to change the intensity profile of a laser beam without the increase in beam divergence which results from conventional techniques. The technique uses a telescope, the first lens of which is designed to introduce an amount of spherical aberration.
J. A. MacAndrew +5 more
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A novel optical system is described which can be used to change the intensity profile of a laser beam without the increase in beam divergence which results from conventional techniques. The technique uses a telescope, the first lens of which is designed to introduce an amount of spherical aberration.
J. A. MacAndrew +5 more
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1984
The highly directive beams attainable with microwave antennas have been utilized to achieve large antenna gain, precision direction finding, and a high degree of resolution of complex targets. The exploration of a wide angular region with such sharp beams requires an involved scanning operation in which the scanning time becomes a limiting factor. This
L. C. Van Atta, T. J. Keary
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The highly directive beams attainable with microwave antennas have been utilized to achieve large antenna gain, precision direction finding, and a high degree of resolution of complex targets. The exploration of a wide angular region with such sharp beams requires an involved scanning operation in which the scanning time becomes a limiting factor. This
L. C. Van Atta, T. J. Keary
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