The programme is based on four ambitious, distinct but interlinked projects with the overarching theme that we challenge the “limits” in photonics, which we aim to overcome through the structuring of light and dielectric media:
(i) Project P1 Structured light for imaging and microscopy. We will explore advanced forms of structured light for imaging and microscopy, especially in the far field and through disordered media. We will structure light by exploiting the exciting concepts of optical eigenmodes, building on our experience with advanced nonzero-order light fields (eg Bessel, Airy) and building on our recent work of light transmission through disordered media. In the longer term, we aim to develop new forms of imaging and microscopy. These methods are based on manipulating the optical phase, amplitude and polarisation involved in image formation, as well as, somewhat counter-intuitively, exploiting the additional k-vectors generated through surface disorder to increase resolution. This work links to structuring for optofluidics (project P2) and to the development of organic and silicon light sources with structured light (projects P3). Outputs can assist P4 and the challenges of P4 (e.g. PDT at depth) will in turn drive P1.
(ii) Project P2 Structured optofluidics. Here, rather than focusing on free space light structuring (as in P1) we turn our attention to the burgeoning field of optofluidics – the marriage of photonics and microfluidics –to shape light via dielectric nanostructured materials, namely photonic crystals. The slot waveguide configuration is of particular interest here, as it allows us to confine light to exquisitely small volumes yet to interact very strongly with a given analyte. We will exploit synergies with P1 on the design approach through eigenmode optimisation and will benefit from a strong connection with developments in P3. In addition, we will tackle the problem of autonomous sensors; most biosensors demonstrated to date only refer to the actual sensor itself, i.e. the transducer, while the light source and detector are typically piped in externally. We will explore a number of original schemes that allow the combination all the key elements on a single chip, thus developing a sensor that can be remotely operated, and that might eventually be deployed in a “lab on a pill” type arrangement.
(iii) Project P3 Structured light emission in organics and silicon. This project deals with the development of novel light sources and the key issues of how we may structure (tailor) them in phase and amplitude (drawing on and in turn driving P1, P2 and P4) with a focus on the emergent area of both silicon and organic light sources. An important aim is to use microstructure to improve the spatial coherence of organic LEDs to give laser-like emission. Such sources will be useful in themselves, and we will then shape the output in phase to explore generation of forms of light such as Bessel modes from thin films.
(iv) Project P4 Structured light for therapeutics. Here we will explore the use of structured light for therapeutic applications. In particular we will explore how structured light may be used to understand and enhance neuron growth, and impact upon the emergent field of optogenetics. This will be complemented by developing compact organic semiconductor devices for measuring neural activity. We will explore the use of novel ‘structured’ sources (for example Bessel light modes, linking to P1 and P3) to give deeper penetration into tissue, which is particularly relevant to photodynamic therapy.