论文标题
通过灵活的多模纤维进行健壮的实时成像
Robust real-time imaging through flexible multimode fibers
论文作者
论文摘要
常规内窥镜包含一束光纤，与图像中的每个像素相关联。原则上，可以将其简化为单个多模光纤（MMF），即人毛的宽度，每个图像像素具有一个纤维空间模式。但是，由于纤维的空间模式之间的分散和耦合，通过MMF传播的图像作为无法识别的斑点模式出现。此外，随着光纤经历弯曲，斑点模式会发生变化，从而使在柔性成像应用中使用MMF更加复杂。在本文中，我们提出了一个使用柔性MMF的实时成像系统，但对弯曲非常健壮。在成像过程中，我们的方法不需要从光纤远端访问或反馈信号。我们利用差异自动编码器（VAE）从斑点重建和分类图像，并证明当光纤的弯曲配置更改为不属于训练集的一部分时，仍然可以恢复这些图像。我们利用300毫米长的MMF，带有一个62.5 UM核心的MMF，将其成像10 x 10 cm的物体，距纤维约20 cm，并且系统可以处理50度的纤维弯曲变化，运动范围为8 cm。
Conventional endoscopes comprise a bundle of optical fibers, associating one fiber for each pixel in the image. In principle, this can be reduced to a single multimode optical fiber (MMF), the width of a human hair, with one fiber spatial-mode per image pixel. However, images transmitted through a MMF emerge as unrecognizable speckle patterns due to dispersion and coupling between the spatial modes of the fiber. Furthermore, speckle patterns change as the fiber undergoes bending, making the use of MMFs in flexible imaging applications even more complicated. In this paper, we propose a real-time imaging system using flexible MMFs, but which is robust to bending. Our approach does not require access or feedback signal from the distal end of the fiber during imaging. We leverage a variational autoencoder (VAE) to reconstruct and classify images from the speckles and show that these images can still be recovered when the bend configuration of the fiber is changed to one that was not part of the training set. We utilize a MMF 300 mm long with a 62.5 um core for imaging 10 x 10 cm objects placed approximately at 20 cm from the fiber and the system can deal with a change in fiber bend of 50 degrees and range of movement of 8 cm.
