Shot-Noise Limited FSRM

拉曼显微镜是一种成熟的成像技术，在生物学、医学和材料科学中有着广泛的应用。利用拉曼特征和分子结构之间的良好相关性，它可以实现无标签成像。由于拉曼信号通常很弱，目前人们正在努力通过非线性效应来增强它们。几年前，我们已经证明了飞秒受激拉曼散射适用于这个目的。与其他一些方法相反，飞秒受激拉曼显微镜（FSRM）技术可以同时产生完整的拉曼光谱。在之前的资助期内，我们已经为FSRM构建了专用的激光光源。该源适用于生物样品。目前，信号质量受到多通道检测器的限制。在这个资助期，我们打算设计出一种探测器，在噪声特性方面达到或接近物理极限，也就是说，我们打算达到单噪声极限。为此，我们将与光学探测器领域的专家罗杰·莱特博士（诺丁汉大学）合作。由于最终目标是生物样品的高质量成像，我们通过对植物组织的研究奠定了基础。对于这些样品，存在使用传统拉曼显微镜的基准结果。

Raman microscopy is an established imaging technique with applications in biology, medicine and material science. Taking profit from the good correlation between Raman signatures and molecular structures it enables label-free imaging. As Raman signals are commonly weak, huge efforts are presently undertaken to enhance them via non-linear effects. A couple of years ago we have demonstrated that femtosecond stimulated Raman scattering is suitable for this purpose. Contrary to some other approaches, the technique, femtosecond stimulated Raman microscopy (FSRM), yields complete Raman spectra simultaneously. In the preceding funding period we have constructed a dedicated laser light source for FSRM. The source is suitable for biological samples. Presently, the signal quality is limited by the multi-channel detector. With this funding period we intend to come up with a detector operating at or close to the physical limit concerning the noise properties, i.e. we intend to reach the shot-noise limit. To this end, we will collaborate with a specialist in the field of optical detectors, Dr. Roger Light (University of Nottingham). Since the ultimate goal is high quality imaging of bio-samples, we lay the foundation on that by investigating plant tissues. For these samples benchmark results using conventional Raman microscopy exist.