Liquid crystal lasers: Towards future ophthalmic imaging technologies

激光的特性在眼科中得到了广泛的应用。手术实例包括玻璃体切割过程中的后凝，得益于光纤激光束输送（与不太精确的电手术相比）和角膜瓣切割的飞秒红外光束，消除了与手动切口相关的角膜破裂的风险。例如，在诊断中，激光可以光学探测上皮内荧光标记的生物标志物，以检测医学异常，如年龄相关性黄斑变性。这种方法的一个限制是，每个生物标志物都有一个特定的光学吸收波长，因此需要几个波长来探测多个荧光团。一个解决方案是使用可调谐激光器。作为一名毕业生，我在工业界工作的前三年都在研究可调谐的固态Ti：蓝宝石激光器。然而，由于其成本，尺寸和重量，这在临床环境中是不切实际的。在过去的三年里，我在眼科从事超声乳化、玻璃体视网膜和屈光系统的工作，激光在这些领域被广泛使用。我亲眼目睹了前面描述的程序，亲眼目睹了对紧凑、可操作和可靠设备的需求。由于许多眼科器械仍然笨重，而且由于技术限制，需要多个系统完成单个手术的不同步骤，因此这些功能仅部分实现。液晶激光器可以为这些限制提供解决方案。这项新开发的技术利用液晶纳米结构的自组装特性来制造10微米厚的空腔。当掺杂多种有机染料时，在450nm-850nm可见范围内实现了高效和可定制的发射。窄线宽液晶激光器的简单、紧凑和可调谐特性，加上生产成本低，有可能发展成为独立的诊断设备或集成到现有的诊断设备中。在临床环境中，这种设备的多功能性将比实现相同结果所需的更大更昂贵的产品具有很大的优势。液晶激光器的发展是我未来导师Philip Hands博士的重点，我与他见过面并详细讨论了这个项目。博士学位的研究范围广泛，包括但不限于：测试不同的化学掺杂剂；不同的微加工技术；优化腔体设计；改善光束质量；将液晶激光器与现有的诊断设备集成和/或为独立单元设计定制的外壳，以在治疗室环境中进行试验。开发液晶激光技术的项目将受益于Hands博士的专业知识和爱丁堡大学提供的广泛资源。我将非常感谢有机会回到大学，并结合我对光子学和眼科的热情，旨在提高眼科疾病的诊断。我相信我所获得的经验、知识和技能将为这个项目带来独特和相关的技能。汉兹博士目前正在与Optos就合作进行谈判，目的是为该项目获得工业赞助。他还与一位眼科医生建立了临床合作关系，后者同意以顾问身份提供支持。

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.