HIGH RESOLUTION MEASUREMENTS OF OPTICAL TOMOGRAPHY IN SCATTERING MEDIUM

发展了基于光频反射法的光学相干层析成像技术。该系统已被应用于鸡组织后反射率的测量。主要结果如下：(1)可调谐光源的光频可在2秒内线性扫描至10THz光频率，无跳模效应。(2)采用CCD摄像机的数据处理系统可以时序存储到512帧的存储器中，并对每个像素数据进行傅里叶变换。(3)采用快速傅立叶变换方法，在短短5分钟的分析时间内，该系统的深度分辨率为47微米。(4)将由两个透镜系统组成的光学系统插入米歇尔森干涉仪中。利用该系统和一个光学外差系统，可以将来自散射介质的强漫反射光抑制到入射光强的10^~(-9)。(5)该系统可以三维测量从表面到几毫米深的强散射介质内的反射率分布。(6)测量了鸡组织后面的反射率，测量时间为2秒。结果表明，该系统可用于三维反射率分布的测量。

Optical coherence tomography based on an optical frequency reflectometry has been developed. The system has been applied to measurements of reflectivity behind chiken tissue. The main results are shown as followings.(1) The optical frequency of tunable laser source can be linearly scanned upto 10 THz during 2 seconds without a mode-hoppe effect.(2) The data processing system with a CCD camera can be time-sequentially stored to memories of 512 frames, and be Fourier-transformed every pixel-data.(3) The depth resolution of this system is 47 mum for five minutes of short analyzing time by using the fast Fourier transform method.(4) The optical system which is constructed of two-lens system is inserted in the Micherlson interferometer. By using this system and an optical heterodyne system, the strong diffuse light from the scattering media was rejected to 10^<-9> of incident light intensity.(5) The system can measure three-dimensionally the reflectivity distribution inside strong scattering media from the surface to the depth of a few millimeters.(6) The reflectivity behind a chiken tissue was measured with measuring time of 2 seconds. From the results, the present system is available to three-dimensional reflectivity distribution measurements.