Liquid crystal lasers: Towards future ophthalmic imaging technologies

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Engineering

Abstract

The properties of lasers are widely utilised in ophthalmology. Surgical examples include posterior coagulation during vitrectomy procedures which benefit from optical fibre laser beam delivery (in contrast to less precise electrosurgery) and femtosecond infrared beams for corneal flap-cutting which eliminate the risk of corneal tears associated with manual incisions. In diagnostics, for example, lasers can optically probe fluorescent-tagged biomarkers within the epithelium to detect medical abnormalities, such as age-related macular degeneration. A limitation of this, is that each biomarker has a particular optical absorption wavelength, thus several wavelengths are needed to probe multiple fluorophores. A solution would be to use a tuneable laser. As a graduate, my first three years in industry were spent working on a tunable solid-state Ti:Sapphire laser. This, however, would be impractical in a clinical environment due to its cost, size and weight. Over the last three years I have worked in ophthalmology with phacoemulsification, vitreoretinal, and refractive systems where lasers are widely used. I have witnessed the previously described procedures and seen first-hand the need for compact, manoeuvrable and reliable devices. These features have only been partially achieved, with many ophthalmic appliances remaining cumbersome, and multiple systems needed to complete different steps of a single procedure due to technological constraints.

Liquid crystal lasers could provide the solution to such limitations. This newly-developed technology exploits the self-assembling properties of liquid crystal nanostructures to create cavities 10 microns thick. When doped with multiple organic dyes, a highly efficient and customisable emission in the visible range of 450nm-850nm is achieved. The simple, compact and tunable properties of narrow-linewidth liquid crystal lasers, combined with the low-cost of production, have the potential to be developed into a stand-alone diagnostic device or integrated into a pre-existing one. The versatility of such a device would be of great advantage in a clinical environment over larger more expensive products needed to achieve the same outcome.

The development of liquid crystal lasers is the focus of my prospective supervisor, Dr Philip Hands, with whom I have met and discussed the project in detail. The PhD has vast scope for investigation including, but not limited to: testing different chemical dopants; varying microfabrication techniques; optimising cavity design; improving beam quality; integrating liquid crystal lasers with existing diagnostic devices and/or designing bespoke housing for a stand-alone unit to trial in a treatment room environment. The project for developing liquid crystal laser technology would benefit from the expertise of Dr Hands and the extensive resources available through the University of Edinburgh. I would greatly appreciate the opportunity to return to the university and combine my passions for photonics and ophthalmology with the aim to improve the diagnosis of ophthalmic diseases. I believe that the experience, knowledge and skills I have acquired would bring a unique and relevant skillset to this project. Dr Hands is presently negotiating a collaboration with Optos, with the intention of securing industrial sponsorship for the project. He has also established a clinical partnership with an ophthalmologist who has agreed to provide support in a consultancy capacity.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R513209/1 01/10/2018 30/09/2023
2103986 Studentship EP/R513209/1 01/09/2018 28/02/2022 Calum Brown