QUantum-Enhanced SpecTroscopic molecular detection - QUEST

Optical instruments are critical to identifying substances and molecules. The spectroscopic detection of molecular species underpins an enormous range of critical techniques and processes used in modern society - from process control and manufacture, pollution monitoring and control, homeland security, and healthcare. As a result of the importance of this technique, spectroscopic detection instrument manufacture is a multi-billion pound global industry, and processes worth many times that depend upon them. The two key metrics by which detector performance are judged are the selectivity (how well the device can distinguish one molecular species from another) and the sensitivity (determining how much of the substance of interest must be present before it can be detected). This project will harness quantum light to increase sensitivity and selectivity of spectroscopic molecular detection.

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 used in the sensor, which hides the very signature fluctuations in the optical signal intensity that enable detection of very minute levels of molecular species. In this project, we will address this by exploiting recent advances in quantum optics - the application of squeezed quantum states of light.With this special form of quantum light, one can choose to sacrifice knowledge of characteristics of the light that one is not interested in, in order to reap gains in others that one desires - in our project, we can maximise knowledge of characteristics that enable increased precision spectroscopy. Such an approach was recently successful in the first steps of helping the next generation of LIGO detectors to search an order of magnitude deeper into the universe for astronomical events causing gravitational waves, than the observed merging of black holes reprted in 2016.

In this project, we will exploit squeezed light for molecular detection with unprecedented sensitivity, thereby enabling detection of far smaller amounts of molecules than are possible with standard techniques. We will achieve this by designing, constructing and demonstrating a protype system that augments state of the art interferometric spectroscopic molecular detection.

Whenever capability in precision measurement advances, history reports benefit to society, including in commerce, national security, advances in healthcare and precision manufacture.
This project represents a crucial step towards harnessing a new paradigm in disruptive sensing and measurement technologies for application outside of the research environment. The fundamental limits of deployed measurement will be extended, and importantly the potential to reduce overall cost and simplify operation will have disruptive impact. The spectroscopic detection market is mature and well understood, and so the role sensors exhibiting the sensitivity we aspire to develop is limited only by the technology price point we can achieve. A key outcome of this proposal is to quantify this impact of our proposed technology - first in the precision sensing market and subsequently onto to benefiting sectors - but naturally we anticipate this project itself will impact on:

- Training skilled technical and research personnel in the engineering and application of practical quantum technology: This is recognized to have far reaching benefits for the UK knowledge economy for the next 30 years and this project represents an acceleration in this respect, by bringing together RTOs (UoB and Fraunhofer-CAP) and industry (Cascade Technologies Ltd) to explore the balance of performance vs cost and market pull of quantum enhanced sensing technology. Training will occur through the direct experience gained by the personnel involved and the generation of new industry led projects for young talent trained by the UK National Quantum Technology Programme, including the PhD students trained by the Quantum Engineering Centre for Doctoral Training (QE CDT) and the Quantum Technology Enterprise Centre incubator (QTEC), both at UoB. We expect the results of this pioneering project to provide motivation for future generations of science and engineering researchers to deploy their skills and knowledge for commercial application.

- Societal impact through increased security: The "Blue lights" services have need for increased sensing precision of deployable, practical molecular identification systems in a range of homeland security and healthcare applications. Another key benefit is in pollution monitoring applications: polluters cannot be expected to observe internationally agreed emission limits and governmental agencies cannot police them if they do not have detection tools exhibiting the required levels of sensitivity and selectivity. A key objective of this project is to demonstrate a low cost, practical and fast molecular detection system that can compete in sensitivity with gold standard, off-line laboratory-based techniques such as mass-spectrometry; an approach, whilst unrivaled in performance, is not deployable in the field or in real-time, in-line end-user applications.

- The UK economy, high-technology business and industry: Increased precision of measurement and sensing impacts on increasingly precise methods for micro- and nano-fabrication, for future drug discovery in the pharmaceuticals industry and for environmental monitoring. The direct engagement with industry enabled by this project will enable knowledge exchange, including education of the wider quantum technology disciplines. Project progress will disseminate through the networks of each partner and their own supply chains - e.g. Fraunhofer-CAP has considerable experience of developing robust and manufacturable photonic systems based on state of the art techniques from photonics research, for application with industry.