QUantum-Enhanced SpecTroscopic molecular detection - QUEST

光学仪器在识别物质和分子方面至关重要。它们用于各种应用，如制造、污染监测、机场安检系统和医疗诊断。通常，分子物种以极少量的形式存在，这使得它们的测量变得困难。这类仪器灵敏度的一个基本限制是激光中存在噪声，它隐藏了光学信号强度中的非常显著的波动，从而能够检测到给定物质的非常微小的水平。在这个项目中，我们将利用量子光学的最新进展--光的压缩量子态的应用--来解决这个问题。在这种特殊形式的量子光中，人们可以选择牺牲自己不感兴趣的光特征的纯度，以获得他人的收益--在我们的情况下，能够进行光谱分析的特征。最近，这种方法在帮助下一代LIGO探测器在更深的太空中搜索引起引力波的天文事件的第一步中取得了惊人的成功。我们将利用压缩光以前所未有的灵敏度进行分子检测，从而使标准技术能够检测到数量小得多的分子。

Optical instruments are critical in identifying substances and molecules. They are used in a diverse range of applications such as manufacture, pollution monitoring, airport security systems and healthcare diagnostics. Often, molecular species are present in minute amounts, making their measurement difficult. A fundamental limit to sensitivity of such instruments is the presence of noise in the laser light, which hides the very signature fluctuations in the optical signal intensity that enable detection of very minute levels of a given substance. In this project, we will address this by exploiting recent advances in quantum optics — the application of squeezed quantum states of light. In this special form of quantum light, one can choose to sacrifice the purity of characteristics of the light that one is not interested in order to reap gains in others that one is - in our case, characteristics that enable spectroscopy. Such an approach was recently and spectactularly successful in the first steps of helping the next generation of LIGO detectors search deeper into space for astronomical events causing gravitational waves. We will exploit squeezed light for molecular detection with unprecedented sensitivity, thereby enabling detection of far smaller amounts of molecules possible with standard techniques.