Nomura Yuki, Yamamoto Kazuo, Anada Satoshi, Hirayama Tsukasa, Igaki Emiko, Saitoh Koh
Technology Division, Panasonic Corporation, 3-1-1 Yagumo-naka-machi, Moriguchi, Osaka 570-8501, Japan.
Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587, Japan.
Microscopy (Oxf). 2021 Jun 6;70(3):255-264. doi: 10.1093/jmicro/dfaa057.
In this study, a noise-reduction technique for series low-dose electron holograms using tensor decomposition is demonstrated through simulation. We treated an entire dataset of the series holograms with Poisson noise as a third-order tensor, which is a stack of 2D holograms. The third-order tensor, which is decomposed into a core tensor and three factor matrices, is approximated as a lower-rank tensor using only noise-free principal components. This technique is applied to simulated holograms by assuming a p-n junction in a semiconductor sample. The peak signal-to-noise ratios of the holograms and the reconstructed phase maps have been improved significantly using tensor decomposition. Moreover, the proposed method was applied to a more practical situation of time-resolved in situ electron holography by considering a nonuniform fringe contrast and fringe drift relative to the sample. The accuracy and precision of the reconstructed phase maps were quantitatively evaluated to demonstrate its effectiveness for in situ experiments and low-dose experiments on beam-sensitive materials.
在本研究中，通过模拟展示了一种使用张量分解的串联低剂量电子全息图降噪技术。我们将带有泊松噪声的系列全息图的整个数据集视为一个三阶张量，它是二维全息图的堆叠。该三阶张量被分解为一个核心张量和三个因子矩阵，并仅使用无噪声主成分近似为一个低秩张量。通过假设半导体样品中的一个p-n结，将该技术应用于模拟全息图。使用张量分解后，全息图和重建相位图的峰值信噪比得到了显著提高。此外，通过考虑相对于样品的不均匀条纹对比度和条纹漂移，将所提出的方法应用于时间分辨原位电子全息术这一更实际的情况。对重建相位图的准确性和精度进行了定量评估，以证明其在对束敏感材料进行原位实验和低剂量实验中的有效性。
