光谱光学相干层析(OCT)系统中, 成像的横向分辨率和焦深之间的矛盾制约了其进一步应用。干涉合成孔径显微技术(ISAM)是一种图像三维重建算法, 通过对光谱数据进行重新采样和计算达到不同深度位置处横向分辨率恒定的目的。通过分析ISAM重构过程和误差原理, 建立多散射点的重构模型, 并对比分析了光谱OCT和ISAM重构后的图像结果。为了缩短ISAM的重构时间, 提出近似波数域方法来实现ISAM, 搭建了光谱OCT成像实验系统。实验结果表明, 该方法极大地节省了重构时间, 将一幅320 pixel×265 pixel图像的重构时间缩短至50 s, 为光谱OCT图像的三维实时重构提供了理论基础。

In the spectral optical coherence tomography(OCT) system, a high depth of field can be achieved at the expense of the poorer transverse resolution. Interferometric synthetic aperture microscopy (ISAM) is an optical computed-imaging technique, which can make transverse resolutions at the different depths identical by resampling the spectrum data. The procedure of ISAM and the principle of error were analyzed and a reconstruction model of multi-scatterers is established. The multiple scatterers simulation is implemented by use of ISAM compared with the standard OCT methods. The approximate wavenumber domain algorithm is applied in ISAM, which can save much rebuilding time without the Stolt interpolation and the spectral OCT experiment system was developed. The experimental results showed that it can greatly reduce computational complexity to enhance the performance of real-time, which costs 50 s to finish one 320 pixel×265 pixel image.