提出了一种无群速度延迟的空间载频谱域光学相干层析成像(OCT)系统消镜像方法。用一块光栅取代传统谱域OCT系统中参考臂内的平面反射镜,在相邻的A—scan之间通过相位调制引入了移项量,同时没有引入任何附加光程差。对得到的干涉光谱信号进行横向傅里叶变换,然后进行滤波,对滤波所得信号进行逆傅里叶变换,最后对得到的信号进行轴向傅里叶变换,就能获得样品消镜像后的OCT图像。介绍了谱域OCT中无群速度延迟的空间载频消镜像方法的实验原理与实验系统,实验研究了平面镜样品在不同调制频率下的成像效果,并给出了平面镜和手指样品消镜像后的OCT图像。
Full range optical coherence tomography (OCT) without additional group delay based on spatial carrier frequency is developed. A grating takes place of the mirror in the reference arm of the traditional OCT system and phase difference between adjacent A-scans without additional optical path difference is introduced by using phage modulation. Spatial interferograms is obtained from the detected OCT signal by the transverse Fourier transform and filtering. For filtering signal, an inverse Fourier transform is done. A full range OCT image can be obtained after axial Fourier transform. The theory and the system based on the spatial carrier frequency are introduced. The investigation on the image quality under different modulation frequencies is experimentally conducted. The full range OCT images of mirror and finger are presented.