Quantum interferometric imaging and quantum nonlinear optics

Wang, Yunkai

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https://hdl.handle.net/2142/121930 Copy

Description

Title

Quantum interferometric imaging and quantum nonlinear optics

Author(s)

Wang, Yunkai

Issue Date

2023-08-18

Director of Research (if dissertation) or Advisor (if thesis)

• Lorenz, Virginia
• Fang, Kejie

Doctoral Committee Chair(s)

Chitambar, Eric

Committee Member(s)

Clark, Bryan

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Quantum optics
• Quantum imaging

Abstract

Quantum information processing based on a photonic platform can be used for many applications exploiting the quantum properties of light. In this thesis, I focus on two aspects of this field: design of integrated optical devices that can implement quantum operations, and distributed quantum sensing, specifically quantum interferometric imaging. Many quantum technologies require photon-photon nonlinear interactions, which are very weak even in nonlinear media, thus requiring the development of an optical device. Most previous studies have considered atom-like quantum systems that can provide strong atom-mediated photon-photon interaction. Here we show weak bulk nonlinearity can be used to create strong nonclassical effects in a waveguide-coupled multimode cavity, which leads to significant applications in quantum circuits and quantum network protocols. For distributed quantum sensing, we first study the usage of a special type of entangled state, a continuous variable graph state, as the probe state, which allows us to achieve a quadratic enhancement in the variance of estimating unknown parameters over the standard quantum limit. For the remainder we focus on a concrete example of distributed quantum sensing, namely quantum-enhanced interferometric imaging, which uses several spatially separated apertures together. We study two aspects of this model: networking and imaging. For the network aspect we study the required resources distributed to the distant detectors for imaging with spatially separated apertures, which leads us to tackle two major issues: reference frame and entanglement. We systematically study the requirement for reference frame in different schemes of interferometric imaging and propose a new method that does not require a shared reference frame. We also propose a new type of astronomical interferometry based on continuous-variable quantum repeaters, which uses a different type of entanglement resource from previous proposals. For the imaging aspect, we assume the ideal implementation of any quantum operations and discuss the fundamental imaging limit. We use quantum parameter estimation theory to study the ability to resolve the distance between two strong thermal point sources, which shows the possibility for superresolution. We also study the bandwidth extrapolation method developed in classical optics and show it can be improved by better measurement strategies. Besides parameter estimation theory, we also study imaging performance by regarding imaging as a qubit state estimation problem, which shows the poor performance of imaging with a fixed separable measurement in the subdiffraction limit.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Yunkai Wang

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