Results 201 to 210 of about 17,852 (256)
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Applied Optics, 2007
Spatial engineering of polarization is proposed as a novel method of beam shaping. It is shown that a flat-top-shaped focus can be obtained in the far field by changing the polarization in the pupil plane in a spatially inhomogeneous manner. Experiments have been carried out to verify the validity of this method in one dimension.
James Leger
exaly +3 more sources
Spatial engineering of polarization is proposed as a novel method of beam shaping. It is shown that a flat-top-shaped focus can be obtained in the far field by changing the polarization in the pupil plane in a spatially inhomogeneous manner. Experiments have been carried out to verify the validity of this method in one dimension.
James Leger
exaly +3 more sources
Superresolution laser beam shaping
Applied Optics, 2004The superresolution technique is well known for its ability to compress the central diffractive spot that is smaller than the Airy diffractive spot. In this paper, we extend the superresolution technique for different laser beam shaping. A complete set of superresolution diffractive elements is developed for the flat-top beam shaping, the single-circle
Jia, Jia +3 more
exaly +3 more sources
SPIE Proceedings, 2006
A novel method for tuning the orbital angular momentum (OAM) content of a vortex beam is presented. This approach makes use of the shaping of the odd and even components of the helical phase profile associated to the vortex. A relative azimuthal shift of the components results in the harmonic variation of the magnitude of the OAM density of the ...
C. López-Mariscal +1 more
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A novel method for tuning the orbital angular momentum (OAM) content of a vortex beam is presented. This approach makes use of the shaping of the odd and even components of the helical phase profile associated to the vortex. A relative azimuthal shift of the components results in the harmonic variation of the magnitude of the OAM density of the ...
C. López-Mariscal +1 more
openaire +1 more source
Optics Letters, 2010
We demonstrate that nondiffracting beams can be generated with an arbitrary transverse shape. In particular, we show that the azimuthal complex modulation of the angular spectra of Helmholtz-Gauss wave fields constitutes a degree of freedom sufficient to tailor nondiffracting beams with an intensity pattern of choice.
Carlos, López-Mariscal +1 more
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We demonstrate that nondiffracting beams can be generated with an arbitrary transverse shape. In particular, we show that the azimuthal complex modulation of the angular spectra of Helmholtz-Gauss wave fields constitutes a degree of freedom sufficient to tailor nondiffracting beams with an intensity pattern of choice.
Carlos, López-Mariscal +1 more
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Statistical approach to beam shaping
Physical Review E, 2005A method for beam shaping based on fitting the power moments of the final beam intensity distribution and independent of the optical system particularities is suggested. It is shown how one can analytically calculate any moment of the final phase space distribution using the moments of the initial distribution and the optical system transfer map ...
Dmitry, Varentsov +2 more
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The British Journal of Radiology, 1972
Experience with shaping of treatment fields utilizing standard accessories for the Theratron-80 cobalt therapy unit suggested that improvement in the beam shaping tray was needed. Sufficient numbers of blocks to fit the shaping tray on the treatment unit head were not readily available, and the overall field size was restricted by the tray itself ...
J C, Baxter, J L, Murray
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Experience with shaping of treatment fields utilizing standard accessories for the Theratron-80 cobalt therapy unit suggested that improvement in the beam shaping tray was needed. Sufficient numbers of blocks to fit the shaping tray on the treatment unit head were not readily available, and the overall field size was restricted by the tray itself ...
J C, Baxter, J L, Murray
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Medical Dosimetry, 1990
Computer control of independent collimator jaw positions and dose is combined with multiple-field summation techniques to design optimized radiation field profiles. Clinically relevant examples are shown for dynamic wedges and compensated mantle fields. Calculation, measurement, and verification techniques are discussed.
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Computer control of independent collimator jaw positions and dose is combined with multiple-field summation techniques to design optimized radiation field profiles. Clinically relevant examples are shown for dynamic wedges and compensated mantle fields. Calculation, measurement, and verification techniques are discussed.
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Beam-shaping unit for micromachining
SPIE Newsroom, 2013Uniform irradiance distribution of laser spot is highly advisable in various micromachining techniques like scribing, PCB and Through-Silicon Via (TSV) drilling, repair techniques in display making technologies. Scanning over whole working field with using popular 2- and 3-axis galvo mirror scanners is another important part of microprocessing systems.
Alexander Laskin +3 more
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Beam combining with using beam shaping
SPIE Proceedings, 2012Performance of spectral beam combining depends on thermal effects on the optical components like volume Bragg gratings used for spectral selectivity of the beams combined. These thermal effects are results of absorption of laser radiation and in case of high power lasers can lead to reduction of efficiency of combining and losses.
Alexander Laskin +5 more
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Beam shaping by holographic filters
Applied Optics, 1989The Gaussian profile of a laser beam can be changed by using a hologram with a suitable phase function. In particular a square and a line of uniform intensity can be generated from a Gaussian input beam.(AIP)
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