Significance: While spectral-domain optical coherence tomography (SD-OCT) is a preferred form of OCT imaging, sensitivity roll-off limits its applicability for certain biomedical imaging applications. Aim: The aim of this work is to extend the imaging range of conventional SD-OCT systems for imaging large luminal organs such as the gastrointestinal tract. Approach: We present an SD-OCT system operating at a center wavelength of 1300 nm that uses two delayed reference arms to reduce sensitivity roll-off and an optical switch and a fiber optic delay line to ensure that the interference spectra are acquired from the same sample time window. Result: The proposed system was used to image swine colon ex vivo and duodenum in vivo, demonstrating improved image quality due to a ∼14 dB increase in sensitivity at the edges of the ranging depth. Conclusion: The proposed system requires modest hardware implementation and is compatible with catheter-based endoscopic helical scanning with enhanced sensitivity for the samples at a distance of ∼6 mm from the zero delay point.

中文翻译：

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改善双参考、缓冲谱域光学相干断层扫描中的灵敏度滚降

意义：虽然谱域光学相干断层扫描 (SD-OCT) 是 OCT 成像的首选形式，但灵敏度下降限制了其在某些生物医学成像应用中的适用性。目的：这项工作的目的是扩展传统 SD-OCT 系统的成像范围，用于对胃肠道等大型管腔器官进行成像。方法：我们提出了一个中心波长为 1300 nm 的 SD-OCT 系统，它使用两个延迟参考臂来减少灵敏度滚降，以及一个光开关和一个光纤延迟线，以确保从相同的采样时间窗口。结果：所提出的系统用于离体猪结肠和体内十二指肠成像，由于测距深度边缘的灵敏度提高了约 14 dB，因此图像质量得到改善。结论：