Development of a coherently controlled multimodal microscope for enhanced biomedical imaging

我们建议开发一种新型光学显微镜，该显微镜将使用定制形状的飞秒脉冲对生物样品中的荧光团进行相干控制激发。整形单元将能够操纵激光束的光谱和空间轮廓，以及调整脉冲不同光谱成分的时间相位和偏振。优化后的激发能提高荧光团激发效率，减少光漂白。飞秒脉冲啁啾调制将使光学检测细胞内的pH值。脉冲整形将为基于三波和四波混频的不同非线性对比机制提供有效的激励。相干控制显微镜将建立在现有的最先进的多模态非线性激光扫描显微镜的基础上，能够同时记录三次和二次谐波，以及多光子激发的荧光图像。这种独特的仪器将非常适合于生物组织和活细胞的非侵入性高分辨率成像。这种新型显微镜将使生物医学成像、细胞动力学、生物能量学和光物理等领域的创新跨学科研究项目成为可能。开发的显微镜将供多伦多大学内外的许多潜在用户使用，并将有助于为高素质人员提供高级显微镜方面的具体培训。

We propose to develop a new type of optical microscope that will use custom shaped femtosecond pulses for coherent control excitation of fluorophores in the biological samples. The shaping unit will be able to manipulate spectral and spatial profiles of the laser beam, as well as adjust the temporal phasing and polarization of different spectral components of the pulse. The optimized excitation will enhance the efficiency of fluorophore excitation and reduce photobleaching. The femtosecond pulse chirp modulation will enable the optical detection of the pH inside the cells. The pulse shaping will provide the efficient excitation for different non-linear contrast mechanisms based on three and four wave mixing. The coherent control microscope will be built on the basis of already existing state-of-the-art multimodal non-linear laser scanning microscope capable of simultaneously recording third and second harmonic, and multiphoton excitation fluorescence images. The unique instrument will be ideally suited for non-invasive high-resolution imaging of biological tissue and live cells. The new microscope will enable a broad range of innovative interdisciplinary research programs in biomedical imaging, cellular dynamics, bioenergetics and photophysics of photosynthesis. The developed microscope will be accessible to a number of potential users within and outside the University of Toronto, and will help to provide specific training in advanced microscopy for highly qualified personnel.