频域光学相干层析术系统中高准确度高灵敏度补偿色散法  

A Method to Improve Precision and Sensitivity of Dispersion Compensation in Fourier Domain Optical Coherence Tomography

作　　者：陈朝良[1] 高万荣[1] 卞海溢[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院光学工程系,南京210094

出　　处：《光子学报》2014年第2期153-158,共6页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.61275198;60978069)资助

摘　　要：将色散测量方法和快速扫描延迟线技术相结合,在谱域光学相干层析系统中实现了对群延迟色散的精确补偿.在该方法中,先在样品臂中放入平面反射镜,等间隔移动参考臂中快速扫描延迟线系统中光栅的位置,同时测量系统参考臂和样品臂之间的群延迟色散差值.当该值为零时,则表明系统色散匹配.将该方法与基于点扩散函数半高宽的方法进行比较,发现基于半高宽方法的测量误差为4.43%,而该方法的测量误差为0.76%;在色散补偿过程中,随着色散匹配点的靠近,半高宽方法的灵敏度由92.105 3fs2减小到1.344 7×103 fs2,而新方法的灵敏度则保持165.789 5fs2,表明本文提出的色散补偿法具有较高的色散补偿准确度和灵敏度.实验表明,色散补偿后的系统分辨率接近理论值;在补偿系统色散的同时,还可以根据测量所得色散值的符号来判定光栅的移动方向,从而更容易地完成补偿工作.A method of compensating dispersion precisely in Fourier domain optical coherence tomography was proposed, based on the combination of the measurements of the values of the dispersion with the rapid scanning optical delay line. Firstly, a plane mirror was placed in the sample arm, and the values of differences of the group delay dispersion were measured while moving the grating in rapid scanning optical delay line to introduce differentdispersion. When the measured value was zero, the dispersion was matched. The new method was compared with the one based on the full width at half maxmum of point spread function. It was found that the measuring error of full width at half maxmum was 4.43% while proposed method was 0. 76% and the sensitivity of full width at half the maxmum decreased from 92. 105 3 fs2 to 1. 344 7）K 10s fsz while it remained 165. 789 5 fs2 in the proposed method. The results show that this method is more accurate and sensitive than the full width at half the maximum. In addition, the direction of grating movement can be determined by the sign of the measured value of dispersion difference, which may be used to compensate dispersion. Finally, the experimental data show that the axial resolution after compensating dispersion nearly approaches the theoretical value.

关 键 词：医用光学 低相干干涉 频域光学相干层析术 快速扫描延迟线 色散补偿 色散测量 傅里叶变换 

分 类 号：TN247[电子电信—物理电子学]