Imaging with Quantum Illumination Techniques

经典成像在灵敏度和分辨率方面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，这导致了对检测对象的灵敏度以及人们可以检测到它们的分辨率的限制。 使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检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，并可以研究这些光场，以了解它们比经典极限好多少。 这种“量子照明”已经被证明能够提高检测灵敏度，但在成像情况下还没有被证明，其中需要非常不同的检测器和光源技术。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的成像领域中是有趣的，其中人们希望避免对组织的损伤。已经证明，原子蒸气中的四波混频可以产生具有有趣的量子特性的光，并且在非平凡成像是可能的条件下这样做。 该项目利用这种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，复印机相位敏感放大器（用于图像的低噪声光学放大器）和量子照明遥感。 将研究量子照明和相干检测的优点在实践中可以实现的程度。 这项工作涉及在干涉传感和成像的背景下新引入的量子技术的调查，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的成像领域中是令人感兴趣的，以避免对组织的损伤。

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.