光学相干层析成像技术中,样品的色散特性将降低获取图像的分辨力。通过实验获取了不同色散特性的样品的相干图像。实验采用中心波长为845nm,频谱宽度为26nm的超辐射光源。实验的样品为一块30mm厚的BK7玻璃。根据光源的频谱信息和样品的色散系数,理论计算了OCT信号的包络,并与实验中测得的信号相对比。同时提出了一种新的数值方法,来补偿样品的色散。该方法可在时域或者频域OCT中方便地应用。通过实验验证了该方法的可行性。
It is known that dispersion in a sample degrades the resolution of signals in optical coherence tomography (OCT). In the paper, we investigate the OCT signals for some samples with different dispersions. A super-luminescent diode source with the center wavelength of 845nm and spectral width of 26nm was used. A 30mm thick BK7 glass slab was tested. Based on the measured source spectrum, the broadened signals are calculated with the specific dispersion coefficients. The calculated signals are compared with the results measured in the experiments. A general numerical dispersion compensation method is introduced, which can be applied both in time and frequency domains. The present method is verified experimentally.