Benjamin E. Koltenbah

Experimental determination and numerical simulation of the properties of negative index of refraction materials

Negative index of refraction materials have been postulated for many years but have only recently been realized in practice. In the microwave region these materials are constructed of rings and wires deposited on a dielectric substrate to form a unit cell. We have constructed, experimentally characterized and simulated several of these structures operating in the 10 - 15 GHz range. Our simulations using Maxwells Equations solvers have included wire arrays, ring arrays and assemblies of unit cells comprised of rings and wires. We find good agreement between the numerical simulations and experimental measurements of the scattering parameters and index of refraction. The procedure was to first model ring and wire structures on the unit cell level to obtain scattering parameters from which effective å, ì and n were retrieved. Next an assembled array of unit cells forming a 12 degrees wedge was used for the Snells Law determination of the negative index of refraction. For the structure examined the computed value of n is within 20% of the one experimentally measured in the Snells Law experiment from 13.6 to 14.8 GHz.

Quantum-enhanced interferometry with weak thermal light

We propose and implement a procedure for enhancing the sensitivity with which one can determine the phase shift experienced by a thermal light beam possessing on average fewer than four photons in passing through an interferometer. Our procedure entails subtracting exactly one (which can be generalized to m) photon from the light field exiting an interferometer containing a phase-shifting element in one of its arms. As a consequence of the process of photon subtraction, the mean photon number and signal-to-noise ratio (SNR) of the resulting light field are increased, leading to an enhancement of the SNR of the interferometric signal for that fraction of the incoming data that leads to photon subtraction.Seyed Mohammad Hashemi Rafsanjani, ∗ Mohammad Mirhosseini, Omar S. Magaña-Loaiza, Bryan T. Gard, Richard Birrittella, B. E. Koltenbah, C. G. Parazzoli, Barbara A. Capron, Christopher C. Gerry, Jonathan P. Dowling, and Robert W. Boyd 5 Institute of Optics, University of Rochester, Rochester, New York 14627 Hearne Institute for Theoretical Physics and Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 Department of Physics and Astronomy, Lehman College, The City University of New York, Bronx, New York 10468 Boeing Research & Technology, Seattle, WA 98124 Department of Physics, University of Ottawa, Ottawa, ON, K1N6N5, Canada (Dated: May 19, 2016)

A quantum radar detection protocol for fringe visibility enhancement

We present analysis of a radar detection technique using a Photon Addition Homodyne Receiver (PAHR) that improves SNR of the interferometer fringes and reduces uncertainty of the phase measurement. This system uses the concept of Photon Addition (PA) in which the coherent photon distribution is altered. We discuss this process first as a purely mathematical concept to introduce PA and illustrate its effect on coherent photon distribution. We then present a notional proof-of-concept experiment involving a parametric down converter (PDC) and probabilistic post-selection of the results. We end with presentation of a more deterministic PAHR concept that is more suitable for development into a working system. Coherent light illuminates a target and the return signal interferes with the local oscillator reference photons to create the desired fringes. The PAHR alters the photon probability distribution of the returned light via interaction between the return photons and atoms. We refer to this technique as “Atom Interaction” or AI. The returning photons are focused at the properly prepared atomic system. The injected atoms into this region are prepared in the desired quantum state. During the interaction time, the initial quantum state evolves in such a way that the photon distribution function changes resulting in higher photon count, lower phase noise and an increase in fringe SNR. The result is a 3-5X increase of fringe SNR. This method is best suited for low light intensity (low photon count, 0.1-5) applications. The detection protocol could extend the range of existing systems without loss of accuracy, or conversely enhance a system’s accuracy for given range. We present quantum mathematical analysis of the method to illustrate how both range and angular resolution improve in comparison with standard measurement techniques. We also suggest an experimental path to validate the method which also will lead toward deployment in the field.

Photon Addition and Subtraction: New Strategies in Metrology

We propose a strategy that provides resolution and sensitivity below the standard metrology limits using photon addition/subtraction at the output.