3,074 research outputs found
Synthesis of an arbitrary axial field profile by computer-generated holograms
Computer-generated holograms are employed to design any desired intensity distribution along the propagation axis for a finite specified distance
Reconstruction of longitudinal distributed incoherent sources
We describe measurement of the degree of coherence induced by a random light source distributed along the longitudinal z axis. If this degree of coherence is measured only between all the in-plane pairs of points placed along the radial lines it is proportional to the Fourier transform of the source’s three-dimensional intensity distribution as seen from the paraxial far zone. A reconstruction of the source shape from the measured degree of coherence is also demonstrated
Three-dimensional imaging of random radiation sources
A method to image random three-dimensional source distributions is proposed. We show that, by using a Michelson stellar interferometer in a prescribed fashion, one is able to measure a special form of a three-dimensional degree of coherence. The inverse Fourier transform of this coherence function yields the three-dimensional intensity distribution of the source as seen from the paraxial far zone
General theorem of spatial coherence: application to three-dimensional imaging
Three-dimensional imaging of incoherent light sources by the Michelson stellar interferometer is considered. When the interferometer’s pinholes are arranged properly, its output result is equivalent to a two-dimensional Fourier hologram that stores information about the source object’s three-dimensional intensity distribution
Interferometric electro-optical signal processors with partially coherent illumination
Fourier- and Hartley-related transforms are realized in a family of interferometers. The implementation of these interferometers as image correlators is investigated theoretically and experimentally with both coherent and spatially incoherent illumination. Several correlators that can be used for pattern recognition are studied and demonstrated experimentally as special cases
Legality of Age Restrictions in the NBA and NFL
This essay examines age eligibility rules in the National Football League (NFL) and the National Basketball Association (NBA), offers analysis of related antitrust and labor law issues, and shares perspective on underlying policies. As a matter of background, the NFL and the NBA are the only major sports organizations that prohibit players from entrance until a prescribed period after high school graduation. Major League Baseball, the National Hockey League, NASCAR, professional tennis, professional golf, and professional boxing have no such rules. Individuals can also partake in professional acting, theater, music, and other entertainment professions without satisfying a period after high school graduation. The same is true of those who enlist in the U.S. armed forces and in various occupations that require maturity and discipline. Such an employment landscape raises inquiry as to why NFL and NBA teams, unlike so many other employers, would agree to boycott any candidate, regardless of talent or skill, until a prescribed period after high school graduation. This inquiry enjoys heightened interest when considering that NFL and NBA teams are incomparable employers, as players may not play in other leagues for similar compensation
Nondiffracting images under coherent illumination
The focal depth of an arbitrary image is extended by optimization of the amplitude and phase distributions over the entire image. We propose a general method that takes advantage of a detector’s (possibly nonlinear) response to incident intensity. We demonstrate the method by computer simulations and experimentally, using computer-generated holograms
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