Ultrafast fibre--based devices for biomedical applications

主要的研究目标是通过构思面向生物医学应用的全光纤、超高速、高灵敏度平台，使非线性成像和传感更接近床边。这项提议旨在加深我们对光在高强度光纤介质中传播的理解，并将这种理解转化为以新型全光纤平台的形式出现的切实成果。该提案包括三个相互关联的主题：超快光源、非线性显微镜/内窥镜和生物传感器。*主题1：新型超快光纤激光器：主题1的目的是研究增加能量、降低噪声和提高全光纤飞秒激光器稳定性的方法，以便它可以作为生物成像(主题2)和生物传感(主题3)平台中的合适光源。这一主题的一个成功成果是实现了一种自启动全光纤飞秒光纤激光器，该激光器提供高功率、低噪声，并且足够稳定，可用于多模显微镜和内窥镜检查。这样的结果将是实现床边成像和诊断应用的重要一步。*主题2：基于光纤的快速宽带相干拉曼散射(CRS)生物成像：主题2的最终目标是通过使用全光纤配置实现指纹区域中厚组织的快速体内光谱成像，以最大化刺激源的信号并将系统噪声降至最低。这可以为快速事件的光谱成像打开大门，例如流动的肿瘤细胞和在体内监测药物在组织中的扩散。*主题3：用于传感的空芯光子晶体光纤：主题3的目标是a)进一步研究我们的空芯光子晶体光纤生物传感平台用于快速和早期检测多囊卵巢综合征(PCOS)。更好地了解卵巢功能和多囊卵巢综合征将有助于开发这种复杂综合征的新治疗策略。我们的SERS-HCPCF平台可以扩展到检测许多其他疾病，包括早期细菌感染，这对脆弱的患者(如老年人、烧伤患者和化疗患者)至关重要，因为及时的干预至关重要。*b)探索基于HC-PCF非线性光谱的新型生物传感平台。这将使我们能够研究双光子诱导的光化学过程，到目前为止，由于很难在小激发体积下探测到光化学事件，这一过程受到了限制。这为研究一些光活性药物，如5-氨基乙酰丙酸(ALA)的光化学机理和产物打开了大门。*。**

The overarching research objective is to bring nonlinear imaging and sensing closer to the bedside by conceiving all-fiber, ultrafast, high-sensitivity platforms targeted at biomedical applications. This proposal seeks to further our understanding of light propagation in fiber media at high intensities, and translate that understanding into tangible outcomes in the form of novel all-fiber platforms. The proposal comprises of three inter-related themes: ultrafast sources, nonlinear microscopy/endoscopy and biosensors.***Theme 1: Novel ultrafast fiber lasers: The objective of Theme 1 is to investigate methods to increase energy, reduce noise and enhance stability of an all-fiber femtosecond laser, such that it may serve as a suitable source within bioimaging (Theme 2) and biosensing (Theme 3) platforms. A successful outcome of this theme is the realization of a self-starting all-fiber femtosecond fiber laser that delivers high power, generates low noise, and is stable enough for multimodal microscopy and endoscopy. Such an outcome would be a significant step towards enabling bedside imaging and diagnostic applications.***Theme 2: Fiber-based Fast Broadband Coherent Raman Scattering (CRS) bioimaging: The ultimate objective of Theme 2 is to enable fast in-vivo spectroscopic imaging of thick tissue in the fingerprint region by using an all-fiber configuration to maximize the signal of the stimulating sources and minimize system noise. This can open the door for spectral imaging of fast events such as flowing tumor cells and in-vivo monitoring of drug diffusion through tissue.***Theme 3: Hollow Core Photonic Crystal fiber for Sensing: The objective of Theme 3 is to a) further investigate the use of our Hollow core photonic crystal fiber biosensing platform for fast and early detection of polycystic ovary syndrome (PCOS). A better understanding of the ovarian function and PCOS would facilitate the development of new treatment strategies for this complex syndrome. Our SERS-HCPCF platform can be extended to detect a number of other diseases including early bacterial infections, which is critical to fragile patients, e.g. the elderly, burn victims, and chemotherapy patients, when timely intervention is of the utmost essence and ***b) explore a novel biosensing platform based on nonlinear spectroscopy in HC-PCF. This would enable us to study two-photon induced photochemistry processes, which until now was limited due to difficulty in detecting photochemical events at a small excitation volume. This can open the door to study photochemical mechanism and products for a number of photoactive drugs, e.g. 5-aminolevulinic acid (ALA). *******.**