Ultrafast fibre­-based devices for biomedical applications

总体研究目标是通过构思针对生物医学应用的全光纤，超快，高灵敏度平台，使非线性成像和传感更接近床边。该提案旨在进一步加深我们对高强度光纤介质中光传播的理解，并将这种理解转化为新型全光纤平台形式的切实成果。该提案包括三个相互关联的主题：超快源，非线性显微镜/内窥镜和生物传感器。 主题一：新型超快光纤激光器：主题1的目的是研究增加能量，降低噪声和增强全光纤飞秒激光器稳定性的方法，使其可以作为生物成像（主题2）和生物传感（主题3）平台中的合适光源。该主题的一个成功成果是实现了自启动全光纤飞秒光纤激光器，该激光器可提供高功率，产生低噪声，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。 主题二：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来最大化刺激源的信号并最小化系统噪声，从而实现指纹区域中厚组织的快速体内光谱成像。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药物通过组织扩散的体内监测。 主题三：用于传感的空芯光子晶体光纤：主题3的目的是a）进一步研究使用我们的空芯光子晶体光纤生物传感平台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PCOS将有助于开发新的治疗策略，这一复杂的综合征。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，这对脆弱的患者至关重要，例如老年人，烧伤患者和化疗患者，当及时干预至关重要时， B）在HC-PCF中探索基于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，这是有限的，由于难以检测在一个小的激发体积的光化学事件。这为研究5-氨基乙酰丙酸（ALA）等光活性药物的光化学反应机理和产物提供了可能。 .

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). .