EXCITATION WAVELENGTH DEPENDENT RAMAN SPECTROSCOPY OF ARTERY

该项目的目标是比较785 nm的性能 和基于830 nm的拉曼光谱定量分析 动脉。硅基电荷耦合器件(CCD)探测器具有低 短波长暗电流和高量子效率 提供散粒噪声有限检测的区域。此外，标准 半导体激光器、全息陷波滤光片、高效光谱仪和 785 nm激光的滤光光纤探头是现成的 激动剂，通常比830中使用的价格更经济 NM激光激发拉曼光谱。然而，生物组织 显示出明显的短波长荧光(例如785 nm) 近红外刺激。我们目前的研究发现，散粒噪声 由荧光背景信号产生的禁止 用785 nm激发拉曼光谱分析动脉疾病。我们 还表明，较长波长的激发确实能够提供 充分减少荧光背景，从而减少拍摄 噪声，以克服目前检测设备的局限性。因此，它 结果表明，830 nm波长激发是一种最佳折衷方案 当前可用的技术和实用的基础 局限性，与我们以前的工作一致。

The goal of this project is to compare the performance of 785 nm and 830 nm based Raman spectroscopy for quantitative analysis of artery. Silicon based charge coupled device (CCD) detectors have low dark current and high quantum efficiency in the short wavelength region offering shot noise limited detection. In addition, standard diode lasers, holographic notch filters, efficient spectrographs and filtered optical fiber probes are readily available for 785 nm laser excitaion, often at economical pricing compared to those used in 830 nm laser excited Raman spectroscopy. However, biological tissue exhibits marked fluorescence with short wavelength (for e.g. 785 nm) NIR stimulation. Our current research has found that the shot noise generated by the fluorescence background signal to be prohibitive to artery disease analysis using 785 nm-excited Raman spectroscopy. We have also shown that longer wavelength excitation indeed affords sufficient reduction in fluorescence background and thus reduced shot noise to overcome present detection equipment limitations. Thus, it was shown that 830nm wavelength excitation is an optimal compromise between currently available technology and practical fundamental limitations, in accord with our previous work.