Imaging with Quantum Illumination Techniques

经典成像在灵敏度和分辨率上受到用于创建图像的光的统计噪声特性的限制。在日常生活中，光的经典描述通常就足够了；然而，这导致了探测物体的灵敏度和分辨率的限制，人们可以探测到它们，这不是基本的。利用光的量子力学描述，可以设想“非经典”光场，这将导致比经典光更好的探测灵敏度和成像分辨率。利用某些材料的非线性光学特性，可以创建非经典光场，并且可以研究这些光场，看看它们比经典极限好多少。这种“量子照明”已被证明能够提高探测灵敏度，但以前还没有在成像情况下被证明，在成像情况下，需要非常不同的探测器和光源技术。这些技术在非常低的光水平下特别有用，因此在活体生物组织成像领域很有趣，因为人们希望避免对组织造成损害。已经证明，原子蒸汽中的四波混合可以产生具有有趣量子特性的光，并且在可能实现非平凡成像的条件下这样做。该项目利用该光源的发展来研究三个不同的想法：“SU（1,1）”干涉仪，它可能超过传统干涉仪的灵敏度，复制相位敏感放大器（用于图像的低噪声光学放大器），以及用于遥感的量子照明。在实践中，量子照明和相干探测的优势在多大程度上可以实现将被研究。这项工作涉及在干涉传感和成像的背景下研究新引入的量子技术，它允许量子噪声限制成像和检测的进一步发展。光束的量子纠缠可以改善成像，并对量子信息处理技术的研究产生影响。这些技术在非常低的光水平下特别有用，因此在活体生物组织成像领域很有趣，以避免对组织造成损害。

Classical imaging is limited in sensitivity and resolution by the statistical noise properties of the light used to create the images. In everyday life a classical description of light usually suffices; however this leads to limitations on both the sensitivity of detecting objects as well as the resolution with which one can detect them that are not fundamental. Using a quantum mechanical description of the light, "non-classical" light fields can be envisioned that will lead to better detection sensitivity and imaging resolution than with classical light. Using non-linear optical properties of certain materials, non-classical light fields can be created and these fields can be investigated to see how much better they are than the classical limits. Such "quantum illumination" has been shown to be capable of improved detection sensitivity, but has not been demonstrated in an imaging situation before, where very different detector and light-source technologies are required. These techniques are especially useful at very low light levels, and thus are interesting in the field of imaging of live biological tissues where one would like to avoid damage to the tissue.It has been demonstrated that four-wave mixing in atomic vapors can generate light with interesting quantum properties, and do so under conditions where non-trivial imaging is possible. This project takes advantage of the development of this light source to investigate three distinct ideas: the "SU(1,1)" interferometer which potentially exceeds the sensitivity of conventional interferometers, the copier-phase sensitive amplifier (a low-noise optical amplifier for images), and quantum illumination for remote sensing. The extent to which the advantages of quantum illumination and coherent detection can be achieved in practice will be investigated. The work involves the investigation of newly introduced quantum techniques in the context of interferometric sensing and imaging, and it allows the further development of quantum-noise-limited imaging and detection. Quantum entanglement of the light beams could allow improvements in imaging, and have an impact on the study of quantum information processing techniques. These techniques are especially useful at very low light levels, and thus are interesting in the field of imaging of live biological tissues in order to avoid damage to the tissue.