Duke University, Department of Biomedical Engineering, Box 90281, Durham, North Carolina 27708, USA.
Opt Lett. 2010 Jul 1;35(13):2305-7. doi: 10.1364/OL.35.002305.
The continuing improvement of high-speed area-scan cameras has made possible the construction of parallel optical coherence tomography (OCT) systems that are competitive with the fastest demonstrated swept-source OCT systems. Unfortunately, when imaging through turbid media using a partially coherent source, parallel OCT suffers resolution loss from coherent multiple scattering, a phenomenon known as crosstalk. We demonstrate the use of a full-field OCT system employing multimode fiber in the illumination arm to reduce the spatial coherence of a partially coherent source. By reducing the spatial coherence area below the system's lateral resolution, we create a spatial coherence gate that rejects these multiply scattered photons. We quantify the image quality and resolution improvement of this method by comparing images of a USAF test chart acquired beneath turbid phantoms using both coherent and incoherent illumination and computing the resulting modulation transfer functions. We demonstrate the feasibility of this method for imaging biological specimens by imaging a Drosophila melanogaster sample.
高速面扫描相机的不断改进使得构建与最快的扫频源光学相干断层扫描（OCT）系统相竞争的平行光学相干断层扫描（OCT）系统成为可能。不幸的是，当使用部分相干光源对混浊介质进行成像时，平行 OCT 会由于相干多重散射而导致分辨率降低，这种现象称为串扰。我们展示了使用全视野 OCT 系统，在照明臂中采用多模光纤来降低部分相干源的空间相干性。通过将空间相干区域降低到系统的横向分辨率以下，我们创建了一个空间相干门，拒绝这些多次散射的光子。我们通过比较在混浊仿体下使用相干和非相干照明获取的 USAF 测试图的图像并计算得到的调制传递函数，来定量评估这种方法对图像质量和分辨率的改善。我们通过对黑腹果蝇样本进行成像，展示了这种方法用于生物样本成像的可行性。
