We present a technique to reduce speckle in visible-light optical coherence tomography (vis-OCT) that preserves fine structural details and is robust against sample motion. Specifically, we locally modulate B-scans orthogonally to their axis of acquisition. Such modulation enables acquisition of uncorrelated speckle patterns from similar anatomical locations, which can be averaged to reduce speckle. To verify the effectiveness of speckle reduction, we performed in-vivo retinal imaging using modulated raster and circular scans in both mice and humans. We compared speckle-reduced vis-OCT images with the images acquired with unmodulated B-scans from the same anatomical locations. We compared contrast-to-noise ratio (CNR) and equivalent number of looks (ENL) to quantify the image quality enhancement. Speckle-reduced images showed up to a 2.35-dB improvement in CNR and up to a 3.1-fold improvement in ENL with more discernable anatomical features using eight modulated A-line averages at a 25-kHz A-line rate.

中文翻译：

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使用扫描调制的可见光光学相干断层扫描中的斑点减少。

我们提出了一种减少可见光光学相干断层扫描（vis-OCT）中的斑点的技术，该技术保留了精细的结构细节，并且对样本运动具有鲁棒性。具体来说，我们在正交于B扫描的采集轴的位置上对其进行本地调制。这样的调制使得能够从相似的解剖位置获取不相关的斑点图案，可以对其进行平均以减少斑点。为了验证散斑减少的有效性，我们在小鼠和人类中使用调制的光栅和环形扫描进行了体内视网膜成像。我们将斑点减少的vis-OCT图像与从相同解剖位置通过未调制B扫描获得的图像进行了比较。我们比较了对比度和噪声比（CNR）和等效外观数（ENL），以量化图像质量增强。减少斑点的图像最多显示2。