arXiv subjects

Christopher C. Tison

Publications and source records attributed to Christopher C. Tison.

23 records · Page 2Linked to original sources

arXiv2018

Introduction to the Absolute Brightness and Number Statistics in Spontaneous Parametric Down-Conversion

As a tutorial, we examine the absolute brightness and number statistics of photon pairs generated in Spontaneous Parametric Down-Conversion (SPDC) from first principles. In doing so, we demonstrate how the diverse implementations of SPDC can be understood through a single common framework, and use this to derive straightforward formulas for the biphoton generation rate (pairs per second) in a variety of different circumstances. In particular, we consider the common cases of both collimated and focused gaussian pump beams in a bulk nonlinear crystal, as well as in nonlinear waveguides and micro-ring resonators. Furthermore, we examine the number statistics of down-converted light using a non-perturbative approximation (the multi-mode squeezed vacuum), to provide quantitative formulas for the relative likelihood of multi-pair production events, and explore how the quantum state of the pump affects the subsequent statistics of the downconverted light. Following this, we consider the limits of the undepleted pump approximation, and conclude by performing experiments to test the effectiveness of our theoretical predictions for the biphoton generation rate in a variety of different sources.

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arXiv2017

Central Moment Analogues to Linear Optically Generated Cluster States

Two-mode squeezed states in the limit of small squeezing, Hong-Ou-Mandel interference and post selection on coincidence counts are some of the staples of linear quantum optics. We show that by using classical expectations on central moments of intensities, we can remove the requirement of small squeezing necessary for high fidelity coincidence detection. Utilizing existing techniques to probabilistically generate a cluster state, we construct a statistical analogue with deterministic generation at the cost of losing the ability to feed forward and requiring statistical averaging.

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arXiv2017

A quantum optical description of losses in ring resonators based on field operator transformations

In this work we examine loss in ring resonator networks from an "operator valued phasor addition" approach (or OVPA approach) which considers the multiple transmission and cross coupling paths of a quantum field traversing a ring resonator coupled to one or two external waveguide buses. We demonstrate the consistency of our approach by the preservation of the operator commutation relation of the out-coupled bus mode. We compare our results to those obtained from the conventional quantum Langevin approach which introduces noise operators in addition to the quantum Heisenberg equations in order to preserve commutation relations in the presence of loss. It is shown that the two expressions agree in the neighborhood of a cavity resonance where the Langevin approach is applicable, whereas the operator valued phasor addition expression we derive is more general, remaining valid far from resonances.

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arXiv2017

Reconsidering Local Hidden Variables: When One is Enough

In this Letter, we explore the possibility of developing Bell inequalities predicated on models using a single Local Hidden Variable (s-LHV), a strict subset of general LHV models. Because of the less strenuous constraints imposed by s-LHV models, we were able to derive a contingent Bell inequality in analogy to the CHSH inequality, but which does not require bounding of measurement statistics. Following this, we show by explicit example that there are cases of states that rule out s-LHV models by violating our inequality, but which nonetheless have a multivariate LHV model. Even so, we show how merely ruling out s-LHV models is still sufficient to allow for fully device independent quantum key distribution (QKD) and entanglement witnessing. This being the case, our inequality illustrates two things. First, it makes fully device-independent QKD on continuous variables substantially more straightforward. Second, it shows how the degree of correlation needed to demonstrate device-independent QKD is distinct from both Bell-nonlocality and EPR-steering. Although nonlocality in general requires ruling out all LHV models, s-LHV models are sufficiently useful to warrant further exploration.

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arXiv2015

On-Chip Quantum Interference from a Single Silicon Ring Resonator Source

Here we demonstrate quantum interference of photons on a Silicon chip produced from a single ring resonator photon source. The source is seamlessly integrated with a Mach-Zehnder interferometer, which path entangles degenerate bi-photons produced via spontaneous four wave mixing in the Silicon ring resonator. The resulting bi-photon N00N state is controlled by varying the relative phase of the integrated Mach-Zehnder interferometer, resulting in high two-photon interference visibilities of V~96%. Furthermore, we show that the interference can be produced using pump wavelengths tuned to all of the ring resonances accessible with our tunable lasers (C+L band). This work is a key demonstration towards the simplified integration of multiple photon sources and quantum circuits together on a monolithic chip, in turn, enabling quantum information chips with much greater complexity and functionality.

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