QUantum-Enhanced SpecTroscopic molecular detection - QUEST

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.