谱域光学相干层析成像系统的实验研究

Experiment Research on Spectral-Domain Optical Coherence Tomography

为改善光学相干层析成像（OCT）技术图像的获取速度和灵敏度,搭建了一套基于光谱干涉法的谱域光学相干层析成像系统（SD-OCT）.该系统采用宽带光源照明,通过光纤迈克尔逊干涉仪产生物体的干涉图形并被光谱仪采集,物体内部结构图像则由干涉图形的傅里叶变换获得.研究表明,SD-OCT的数据获取速度比传统的OCT系统提高了将近40倍,达到了16 000/s的轴向扫描速率,其灵敏度也改善了20～30 dB.因此,SD-OCT可实现工程和生物材料内部结构的实时三维图像重构.

To improve the image acquisition rate and sensitivity of optical coherence tomography （OCT） technique, a spectral-domain optical coherence tomography （SD-OCT） system based on a spectral interferometric is constructed, where a broadband light source is chosen as the illumination source and a Michelson fiber interferometer is employed to generate interference pattern of object collected by a spectrometer. The object inner structure is obtained from the interference pattern by a Fourier transform. It is theoretically stated and experimentally verified that SD-OCT system outperforms the conventional OCT system in acquisition rate and sensitivity. The acquisition rate gets 16 000 axial scans per second and 40 times the conventional OCT; the sensitivity is enhanced by 20-30 dB. As a result, the SD-OCT system enables to realize near real time three dimensional imaging reconstructions of internal structure of engineering and biological materials.