利用变迹术和相干门相结合实现光学相干层析成像术轴向超分辨

光学相十层析成像（光学相干层析成像术）的轴向分辨力由光源带宽和探测光束的聚焦条件共同决定。提高光学相干层析成像术轴向分辨力的方法主要基于带宽光源技术。提出了一种将变迹术与光学相十层析成像术相干门有机结合的方法来提高其轴向分辨力。通过适当形式的光瞳滤波器．使光学相干层析成像术系统轴向响应的主瓣宽度缩小到相干门之内，而其旁瓣则处于相干门之外．不对相干成像产生有效贡献。这样．就能在光源带宽不变的条件下，有效提高光学相十层析成像术的轴向分辨力，避免了采用宽带光源所带来的费用昂贵和系统复杂等缺陷。

Axial Superresolution in Optical Coherence Tomography Through the Combination of Apodization and Coherence Gating

Axial resolution in optical coherence tomography(OCT) imaging is determined by the coherence length of light source and the beam-focusing condition.The most adopted approach for achieving high axial resolution in OCT is using a light source with a broaden bandwidth.A method to increase the axial resolution in OCT by combining coherence gating with apodization through an appropriate pupil filter is introduced.In the proposed OCT system,the width of central lobe of axial point spread function is apodized to be within the coherence length of light source,while its side-lobes are lying outside without contributing to coherence imaging.It is in this way that improved resolution can be obtained in OCT system without recurring to broadening the bandwidth of light source,which is nevertheless costing and inconvenient in implementation.