PROOF OF PRINCIPLE FOR FIELD BASED REFLECTANCE SPECTROSCOPY

实验使用了皮秒激光和时间分辨的单脉冲 光子计数检测。为了研究光子路径，一个带有 在装满水溶液的容器中插入了一个小针孔 聚苯乙烯微球的平均自由程为20-200 容器)。带有针孔的屏幕被用来探测光子 散射介质内的路径。通过改变 在介质针孔中，时间分辨的光子路径分布可以 被规划出来了。定义明确的时间分辨光子的存在 这些实验所演示的路径为 三维光学层析成像方案。结果发表在《纽约时报》 与输运方程的路径积分解非常吻合 并且偏离了使用扩散近似计算的路径。

The experiments employ a picosecond laser and time-resolved single photon counting detection. To study the photon paths, a screen with a small pinhole was inserted in the container filled with water solution of polystyrene microspheres (20-200 mean free paths across a container). The screen with pinhole was used to probe the photon paths within the scattering medium. By varying the position of the pinhole in the medium, the time-resolved photon path distribution can be mapped out. The existence of well-defined time-resolved photon paths demonstrated by these experiments provides the basis for a three-dimensional optical tomographic scheme. The results were in excellent agreement with path integral solution of transport equation and deviated from paths calculated using diffusion approximation.