Research in Quantum-Enhanced, Ultrafast Sensing and Imaging

本文概述了一项研究计划，以开发具有量子增强探测灵敏度的超宽带成像的实用方法。特别地，它提出了几种表征超快光学和x射线波形的新技术，然后讨论了将它们应用于宽带动态成像的方法，包括远远超过相位和幅度测量精度的短噪声限制的可能性。该计划涵盖了适当的动态图像检测、图像传输协议和增强灵敏度所需的特定量子态源的开发。该计划有四个主要的实验目标。(1)第一个目标是开发一种测量超快光脉冲完整时空特性的新方法。其基本思想是将超快脉冲测量的干涉测量方法扩展到精度和精密度的新领域。特别是，我们将开发一种用于动态时空成像的超快多波长干涉测量法。（II）我们计划的第二部分需要开发一种用于获得动态X射线成像的阿秒时间分辨率的新方法。该项目将首先研究最近证明的原子电离非线性光学机制，以实现干涉脉冲测量技术，以完全表征阿秒脉冲的电场。该技术是基于电子电离的两种途径上的量子干涉，导致电子能谱中的干涉图样。利用这种模式，可以用一种简单的、非迭代的算法重建电离阿秒脉冲的光谱相位。（三）另一个项目涉及利用超短波光子波包的纠缠态实现近场显微镜的时间分辨和量子增强灵敏度。这提供了相位灵敏度在原则上远远超过射击噪声的限制，并将允许超灵敏的纳米尺度测量的发展，当与近场显微镜的标准实验室方法相结合。该方法的新颖之处在于非经典光不需要进入干涉仪探测相移物体，利用局部纠缠实现量子增强。最后的努力将是开发一种安全传输以超短单光子编码的图像的方法：一种超宽带量子隐形传态。这项工作通过探索多模隐形传态的可能性，探索了量子通信的新途径，并建立在最近在高量子效率CCD阵列探测器的量子光学应用中的工作基础上。这为量子态测量提供了一种新的工具，它本身具有有用的成像应用，并为隐形传态协议提供了所需的宽带经典信息。

This document outlines a program of research to develop practical methods for ultrabroadband imaging with quantum enhancement of the detection sensitivity. In particular it presents several novel techniques for the characterization of ultrafast optical and X-ray waveforms, and then discusses ways to apply them to broadband dynamical imaging, including possibilities for going well beyond the shot-noise limit for phase andamplitude measurement accuracy. The program covers both development of appropriate dynamical image detection, protocols for image transmission, and the sources of particular quantum states needed for enhanced sensitivity.The program has four major experimental objectives. (I) The first goal consists of developing a novel method for measuring the conplete spatio-temporal properties of an ultrafast optical pulse. The basic idea involves extending interferometric methods of ultrafast pulse measurement into a new domain of accuracy and precision. In particular we shall develop an ultrafast multi-wavelength interferometry: for dynamical space-time imaging. (II) The second portion of our program entails the development of a novel method for obtaining attosecond temporal resolution for dynamical X ray imaging. The project will first study a recently demonstrated nonlinear optical mechanism for atomic ionization to implement an interferometric pulse measurement technique for completely characterizing the electric field of the attosecond pulse. This technique is based on the quantum interference on two pathways for ionizing an electron, which leads to an interference pattern in the electron energy spectrum. From this pattern the spectral phase of the ionizing attosecond pulse can be reconstructed using a simple, noniterative, algorithm. (III) Another project involves the use of entangled states of ultrashort photon wavepackets to implement time-resolved and quantum-enhanced sensitivity for near-field microscopy. This provides phase sensitivity in principle well beyond the shot noise limit, and will allow the development of ultrasensitive nanoscale measurement when combined with standard laboratory methods of near-field microscopy. A novel feature of the approach is that the nonclassical light does not need to enter the interferometer and probe the phase shifting object the quantum enhancement is achieved using local entanglement. (IV) The final effort will be to develop a means for the secure transmissionof images encoded in ultrashort single photons: a type of ultrabroadband quantum teleportation. This work explores new avenues in quantum communications by exploring possibilities for multimode teleportation and builds upon recent work in the applications in quantum optics of high-quantum efficiency CCD array detectors. These provide a novel tool for both quantum state measurement, which itself has useful imagingapplications, and for providing the broadband classical information needed for the teleportation protocol.