Results 171 to 180 of about 6,788 (257)
Matrix-based imaging through dynamic scattering. [PDF]
Nat CommunSunray E, Weinberg G, Laufer B, Katz O.
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Multiplexing and Demultiplexing of Aperture-Modulated OAM Beams. [PDF]
Sensors (Basel)Wang W +6 more
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Relaxed fabrication tolerances for low-Fresnel-number lenses
Journal of the Optical Society of America A, 1997 Numerical simulations have been performed to study the influence of resist-developing errors on continuous-relief microlenses. For very low Fresnel numbers (N 2), the focal length is essentially determined by the diffraction at the lateral pattern of the segments, and deviations from the ideal blaze influence only the efficiency.
Thomas Hessler, Rino E. Kunz
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WEAK TURBULENCE IN A HIGH FRESNEL NUMBER DYE LASER
International Journal of Bifurcation and Chaos, 1994 Local spatiotemporal chaos found in a dye laser has been experimentally studied and characterized as a weak turbulent system. Furthermore, a new model based on a discrete version of the Maxwell-Bloch equations seems to agree with the experimental results.
Pérez-García, Víctor M. +1 more
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Large Effective Fresnel Number Confocal Unstable Resonators: an Experimental Study
Applied Optics, 1974 An experimental study was performed on the beam quality of large equivalent Fresnel number positive confocal unstable square resonators in a CO(2) electron-beam ionized laser. Near diffraction limited output was observed for a range of geometric output coupling from 34% to 85%, with a sensitivity to the particular value of equivalent Fresnel number ...
H, Granek, A J, Morency
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Imaging with finite values of Fresnel number
Journal of the Optical Society of America, 1982 A theory of imaging in the confocal scanning microscope that takes account of the finite Fresnel number of the objectives is developed. It is shown that the coherent transfer function has no definite spatial frequency cutoff, the higher frequencies being enhanced in low-Fresnel-number geometries accompanied by sign reversal and oscillation of the ...
T. Wilson, C. J. R. Sheppard
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Dependence of the focal shift on Fresnel number and f number
Journal of the Optical Society of America, 1982 The behavior along the axis of the intensity arising from the diffraction of a uniform, converging spherical wave at a circular aperture is studied on the basis of the theory of the boundary-diffraction wave. The results are used to determine the location of the principal intensity maximum and to elucidate the dependence of the focal shift both on the ...
Yajun Li
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Three-dimensional intensity distribution in low-Fresnel-number focusing systems
Journal of the Optical Society of America A, 1987 Investigations of the three-dimensional intensity distribution near the focus are extended here to systems with Fresnel numbers N < 0.5. Isophotes (contours of equal intensity) are presented that demonstrate the structure of the field deep within the region of Fresnel diffraction.
Yajun Li
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Local irregular intensity fluctuations in high-Fresnel-number dye lasers
SPIE Proceedings, 1998 Local intensity fluctuations in a large aperture dye laser have been analyzed. We have studied the influence of solvent viscosity in the amplitude of these fluctuations. This experimental result provide a clear evidence of the role played by the molecular orientation in the spatio-temporal laser dynamics.
Jose M. Guerra +2 more
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Nonlinear focal shift in medium Fresnel-number focused acoustic beams
2010 IEEE International Ultrasonics Symposium, 2010 The study of the acoustic field characteristics generated by focusing sources, both in linear and nonlinear regime, is an active field of research as they are relevant in most of the ultrasonic applications in medicine and industry. Particularly, the linear focal shift phenomenon (i.e.
Francisco Camarena +4 more
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