Research on spectrotomography inside skin by supercontinuum white light

本研究的目的是开发一种产生稳定的超连续谱白光源的方法，并证明利用超连续谱白光源重建人体皮肤内部光谱图像的可行性。研究得到的结果如下。1)超连续谱白光源阵列为了利用钛蓝宝石激光器产生稳定的超连续谱白光源，我们尝试使用微透镜阵列来产生超连续谱白光源阵列，并成功地同时产生了大约100个超连续谱白光源。我们还通过时间分辨纹影光学观测研究了产生超连续谱白光源的细丝形成的统计特征。2)超连续光谱白光空间相干性的研究研究了超连续光谱白光阵列中各基本光源之间的光学相干性，并测量到了极高的空间相干性。我们还通过实验证明，在液体和固体中由一束Ti形成的多个灯丝中，两个灯丝产生的光之间具有高的空间相干性；蓝宝石超短激光脉冲。3)光谱层析我们构建了非色散和色散相干光谱层析系统，可以同时测量物体内部的空间和光谱信息。该系统利用超连续白光光源作为光源。我们从层状介质的空间分辨率极限、光谱分辨率、信噪比等方面对系统进行了评价。将色散相干光谱系统应用于小虾，对色散相干光谱系统进行了评价。我们成功地获得了虾尾清晰的光谱断层图像。然而，由于超连续谱白光光源的不稳定性，其在人体皮肤上的应用实验一直无法进行。本研究成果已部分发表（Optical Review; 1999, Japanese Journal of Applied Physics; 2001），并发表评论论文（Optical Review; 2000, Japanese Journal of Optics; 2000）。其余的研究结果正在准备发表。少

The purpose of this research work is to develop a method to generate stable supercontinuum white-light sources and to prove *e feasibility of reconstructing spectrotomographic images inside human skin using the supercontinuum white-light sources. The results obtained in the researchare listed below.1) Array of supercontinuum white-light sourcesTo generate stable supercontinuum white-light sources by using the Ti : Sapphire laser light, we attempted to generate an array of supercontinuum white-light sources by use of a microlens array and succeeded in generating approximately 100 supercontinuum white-light sources simultaneously. We also investigated the statistical characteristics of formation of the filaments that generate the supercontinuum white-light sources by time-resolved Schlieren-optics observation.2) Study of spatial coherence of supercontinuum white-lightThe optical coherence between the elementary sources in the array of supercontinuum white-light sources has been studied a … More nd extremely high spatial coherence was measured. We also showed experimentally that the high spatial coherence between the lights generated in two filaments of the multiple filaments that are formed in the liquid and solid by a single beam of the Ti ; Sapphire ultrashort lasers pulses.3) SpectrotomographyWe built a non-dispersive and a dispersive coherence spectrotomography systems that measure simultaneously the spatial and spectral information inside the object. The systems make use of the supercontinuum white-light source as a light source. We evaluated the systems in terms of spatial resolution limit of layered media, spectral resolution, signal-to-noise ratio. The dispersive coherence spectrotomograpy system was evaluated by applying the system to small shrimps. We succeeded in obtaining clear spectrotomography image of the tail of shrimp. Due to the instability of supercontinuum white-light source, however, the application experiments to human skin could not committed.The results of this research were partly published (Optical Review ; 1999, Japanese Journal of Applied Physics ; 2001) and review papers were also published (Optical Review ; 2000, Japanese Journal of Optics ; 2000). The rest of the results are under preparation for publication. Less