Advanced Optical Frequency Comb Technologies and Applications

Technologies underpin economic and industrial advances and improvements in healthcare, education and societal and public infrastructure. Technologies of the future depend on scientific breakthroughs of the past and present, including new knowledge bases, ideas, and concepts. The proposed international network of interdisciplinary centre-to-centre collaborations aims to drive scientific and technological progress by advancing and developing a new science platform for emerging technology - the optical frequency comb (OFC) with a range of practical applications of high industrial and societal importance in telecommunications, metrology, healthcare, environmental applications, bio-medicine, food industry and agri-tech and many other applications.

The optical frequency comb is a breakthrough photonic technology that has already revolutionised a range of scientific and industrial fields. In the family of OFC technologies, dual-comb spectroscopy plays a unique role as the most advanced platform combining the strengths of conventional spectroscopy and laser spectroscopy. Measurement techniques relying on multi-comb, mostly dual-comb and very recently tri-combs, offer the promise of exquisite accuracy and speed. The large majority of initial laboratory results originate from cavity-based approaches either using bulky powerful Ti:Sapphire lasers, or ultra-compact micro-resonators. While these technologies have many advantages, they also feature certain drawbacks for some applications. They require complex electronic active stabilisation schemes to phase-lock the different single-combs together, and the characteristics of the multi-comb source are not tuneable since they are severely dictated by the opto-geometrical parameters of the cavity. Thus, their repetition rates cannot be optimised to the decay rates of targeted samples, nor their relative repetition rates to sample the response of the medium. Such lack of versatility leads to speed and resolution limitations. These major constraints impact the development of these promising systems and make difficult their deployment outside the labs.

To drive OFC sources, and in particular, multi-comb source towards a tangible science-to-technology breakthrough, the current state of the art shows that a fundamental paradigm shift is required to achieve the needs of robustness, performance and versatility in repetition rates and/or comb optical characteristics as dictated by the diversity of applications. In this project we propose and explore new approaches to create flexible and tunable comb sources, based on original design concepts. The novelty and transformative nature of our programme is in addressing engineering challenges and designs treating nonlinearity as an inherent part of the engineering systems rather than as a foe. Using the unique opportunity provided by the EPSRC international research collaboration programme, this project will bring together a critical mass of academic and industrial partners with complimentary expertise ranging from nonlinear mathematics to industrial engineering to develop new concepts and ideas underpinning emerging and future OFC technologies.
The project will enhance UK capabilities in key strategic areas including optical communications, laser technology, metrology, and sensing, including the mid-IR spectral region, highly important for healthcare and environment applications, food, agri-tech and bio-medical applications. Such a wide-ranging and transformative project requires collaborative efforts of academic and industrial groups with complimentary expertise across these fields. There are currently no other UK projects addressing similar research challenges. Therefore, we believe that this project will make an important contribution to UK standing in this field of high scientific and industrial importance.