Time filter

Source Type

Piscataway, NJ, United States

McKinstrie C.J.,Applied Communication science
Optics Express | Year: 2015

Simultaneous parametric amplification and frequency conversion is a three-mode parametric process. In this paper, the three-mode equations are solved, and the adjoint (spectral) and Schmidt (singular value) decompositions of the associated transfer matrix are determined. The properties and uses of both decompositions are described briefly. These three-mode results show that Schmidt decompositions are fundamentally different from adjoint decompositions, and illustrate other important features of multiple-mode parametric processes. © 2015 Optical Society of America.

McKinstrie C.J.,Applied Communication science | Marshall K.,University of Toronto | Weedbrook C.,University of Toronto
Optics Express | Year: 2015

The noise properties of phase-insensitive and phase-sensitive optical transmission links are described in detail, for Gaussian input signals. Formulas are derived for the quadrature covariance matrices of the output signals, which allow one to quantify the noise figures of the links and the fidelities of transmission. Another formula is derived, which relates the density operator of an output signal, in the number-state representation, to its covariance matrix. This density matrix allows one to quantify the decrease in coherence and changes in photon-number probabilities associated with transmission. Based on the aforementioned performance metrics, links with distributed phase-sensitive amplification perform significantly better than other links. © 2015 Optical Society of America.

Rutar N.,Applied Communication science | Hollingsworth J.K.,University of Maryland University College
Parallel Computing | Year: 2013

Data centric analysis using direct measurements has been established as a successful performance analysis technique. Information gathered with this technique can map cache misses to program variables. These mappings can then be used to address data locality problems and other issues. Existing approaches rely on special hardware support which is needed to negate a 'skid' factor. Our approach is viable when the special hardware support is not present, but where skid is still an issue. Prior methods also rely on maintaining runtime information about memory allocation addresses for variables, which may lead to program perturbation. Our approach uses software analysis to eliminate the need for maintaining allocation and free records. We show that by using heuristics our technique can attribute cache misses to program variables while maintaining the approximate rank-order found by using traditional techniques. We also show that there exists a high correlation between the misses attributed by our approximation and the misses assigned by examining direct measurements. © 2012 Elsevier B.V. All rights reserved.

Reddy D.V.,University of Oregon | Raymer M.G.,University of Oregon | McKinstrie C.J.,Applied Communication science
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

All classical and quantum technologies that encode in and retrieve information from optical fields rely on the ability to selectively manipulate orthogonal field modes of light. Such manipulation can be achieved with high selectivity for polarization modes and transverse-spatial modes. For the time-frequency degree of freedom, this could efficiently be achieved for a limited choice of approximately orthogonal modes, i.e., nonoverlapping bins in time or frequency. We recently proposed a method that surmounts the selectivity barrier for sorting arbitrary orthogonal temporal modes [Opt. Lett. 39, 2924 (2014).OPLEDP0146-959210.1364/OL.39.002924] using cascaded interferometric quantum frequency conversion in nonlinear optical media. We call this method temporal-mode interferometry, as it has a close resemblance to the well-known separated-fields atomic interferometry method introduced by Ramsey. The method has important implications for quantum memories, quantum dense coding, quantum teleportation, and quantum key distribution. Here we explore the inner workings of the method in detail, and extend it to multiple stages with a concurrent asymptotic convergence of temporal-mode selectivity to unity. We also complete our analysis of pump-chirp compensation to counter pump-induced nonlinear phase modulation in four-wave mixing implementations. © 2015 American Physical Society.

Applied Communication Science | Date: 2013-02-19

A method for active learning using privileged information is disclosed. A processing device receives a set of labeled examples and a set of unlabeled examples. For each unlabeled example in the set of unlabeled examples, the processing device determines whether to query at least one of an oracle to obtain a label for the unlabeled example or a teacher to obtain privileged information about the unlabeled example. The processing device outputs a decision rule based on minimizing a number of queries to the oracle for a label and the teacher for privileged information. Minimizing the number of queries to the teacher and the oracle is based on a cost of querying the teacher or the oracle.

Discover hidden collaborations