Deborah J. Jackson

Optical transmission characteristics of fiber ring resonators

We present the results of an experimental investigation of the transfer characteristics of a fiber ring resonator for various values of the resonator finesse. In particular, we measure the spectral dependence of the intensity transmission and the induced phase shift in the undercoupled, critically coupled, and overcoupled regimes. We also demonstrate tunable optical (true time) group delay via a fiber ring resonator and show that a high finesse is unnecessary. Our laboratory results are in excellent agreement with theoretical predictions.

Securing QKD Links in the Full Hilbert Space

Many quantum key distribution QKD analyses examine the link security in a subset of the full Hilbert space that is available to describe the system. In reality, information about the photon state can be embedded in correlations between the polarization space and other dimensions of the full Hilbert space in such a way that Eve can determine the polarization of a photon without affecting it. This paper uses the concept of suitability Hockney et al. “Suitability versus Fidelity for Rating Single Photon Guns” to quantify the available information for Eve to exploit, and demonstrate how it is possible for Alice and Bob to fool themselves into thinking they have a highly secure link.

Optical communication noise rejection using correlated photons

This paper describes a completely new way to perform noise rejection using a two-photon sensitive detector and taking advantage of the properties of correlated photons to improve an optical communications link in the presence of uncorrelated noise. In particular, a detailed analysis is made of the case where a classical link would be saturated by an intense background, such as when a satellite is in front of the sun, and identifies a regime where the quantum correlating system has superior performance.

Error analysis of high data rate, optical parallel processors

Optical parallel processors have the potential for aiding the transfer of information over networks. The systems implications for a baseline architecture employing spatial light modulators, lenses, and charge-coupled devices are examined. Specifically, because many applications have stringent requirements on errors, this study concentrates on categorizing the potential error sources-both random and systematic-and presents the results of an error analysis for a pixel-to-pixel mapping system as a notional example.

Coupled-resonator-induced transparency in a fiber system

We observe splitting of the modes in a coupled-fiber-ring resonator system. This splitting leads to a greatly enhanced transmission (cancellation of absorption) on resonance. We show the analogies between this effect and classical electromagnetically induced transparency.

Mode splitting in a fiber coupled-resonator system

We study mode splitting in a coupled fiber-ring resonator system. Cancellation of absorption on resonance is observed and explained in terms of destructive interference of the symmetric and anti-symmetric modes of the system.

Detector efficiency limits on quantum improvement

Abstract Although the National Institute of Standards and Technology has measured the intrinsic quantum efficiency of Si and InGaAs avalanche photo diode (APD) materials to be above 98% by building an efficient compound detector, commercially available devices have efficiencies ranging between 15 and 75%. This means bandwidth, dark current, cost, and other factors are more important than quantum efficiency for existing applications. For non-classical correlated photon applications, the systems correlated signal-to-noise ratio is proportional to (ηN)½ /(1 − η)½, rather than the classical signal-to-noise (ηN)½. Consequently, the detector design trade space must be re-evaluated. This paper systematically examines the generic detection process, lays out the considerations needed for designing detectors for non-classical applications, and identifies the ultimate physical limits on quantum efficiency.

High quantum efficiency photodetectors for quantum instruments

Achieving detector quantum efficiencies of 90% or greater is enabling for many experiments involving squeezed and entangled light. This paper discusses why poor quantum efficiency reduces one’s ability to exploit squeezed light and describes a light trap approach to improving the detection quantum efficiency.