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This paper discusses issues related to the delivery of MPEG-4 video over the Internet and wireless channels. MPEG-4's built-in error resilience capabilities such as flexible re-synchronization markers, data partitioning, header protection, reversible VLCs, and forced intra-frame refresh are described. Methods for using these techniques to build a(More)
There exists a substantial body of theory that predicts mutual screening of signed topological singularities (topological charges) in random optical fields (speckle patterns). Such screening appears to be rather mysterious because there are neither energetic nor entropic reasons for its existence. We present the first experimental confirmation of mutual(More)
Umbilic points--singular points of curvature characterized by a fractional topological charge q=+/-1/2--are the most numerous of all special points in the landscape of random optical fields (speckle patterns), outnumbering maxima, minima, saddle points, and optical vortices. To the best of our knowledge, we present the first experimental evidence that(More)
The use of quantum correlations between photons to separate measure even- and odd-order components of polarization mode dispersion (PMD) and chromatic dispersion in discrete optical elements is investigated. Two types of apparatus are discussed which use coincidence counting of entangled photon pairs to allow sub-femtosecond resolution for measurement of(More)
*-This paper presents the benefits and challenges in the encoding and delivery of variable bitrate (VBR) MPEG video. The network resources required to transmit stored variable rate MPEG can be reduced by properly analyzing and smoothing the video stream before transmission. A scheduling technique is presented which selects a traffic contract for a(More)
A point of circular polarization embedded in a paraxial field of elliptical polarization is a polarization singularity called a C point. At such a point the major axis a and minor axis b of the ellipse become degenerate. Away from the C point this degeneracy is lifted such that surfaces a and b form nonanalytic cones that are joined at their apex (the C(More)
A broadband source of polarization entangled photons based on type-II spontaneous parametric down conversion from a chirped PPKTP crystal is presented. With numerical simulation and experimental evaluation, we report a source of broadband polarization entangled states with a bandwidth of approximately 125 nm for use in quantum interferometry. The technique(More)