Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
PLoS One. 2013;8(2):e56930. doi: 10.1371/journal.pone.0056930. Epub 2013 Feb 15.
Spatial light interference microscopy (SLIM) is a highly sensitive quantitative phase imaging method, which is capable of unprecedented structure studies in biology and beyond. In addition to the π/2 shift introduced in phase contrast between the scattered and unscattered light from the sample, 4 phase shifts are generated in SLIM, by increments of π/2 using a reflective liquid crystal phase modulator (LCPM). As 4 phase shifted images are required to produce a quantitative phase image, the switching speed of the LCPM and the acquisition rate of the camera limit the acquisition rate and, thus, SLIM's applicability to highly dynamic samples. In this paper we present a fast SLIM setup which can image at a maximum rate of 50 frames per second and provide in real-time quantitative phase images at 50/4 = 12.5 frames per second. We use a fast LCPM for phase shifting and a fast scientific-grade complementary metal oxide semiconductor (sCMOS) camera (Andor) for imaging. We present the dispersion relation, i.e. decay rate vs. spatial mode, associated with dynamic beating cardiomyocyte cells from the quantitative phase images obtained with the real-time SLIM system.
空间光干涉显微镜 (SLIM) 是一种高灵敏度的定量相位成像方法，能够在生物学及其他领域进行前所未有的结构研究。除了样品散射光和非散射光之间的相移产生的π/2 相移外，通过使用反射式液晶相调制器 (LCPM) 以 π/2 的增量产生 4 个相移。由于需要 4 个相移图像来生成定量相位图像，因此 LCPM 的切换速度和相机的采集率限制了采集率，从而限制了 SLIM 对高动态样本的适用性。在本文中，我们展示了一种快速的 SLIM 装置，其最大帧率可达 50 帧/秒，并且可以以 50/4=12.5 帧/秒的实时速度提供定量相位图像。我们使用快速的 LCPM 进行相移，以及快速的科学级互补金属氧化物半导体 (sCMOS) 相机 (Andor) 进行成像。我们从实时 SLIM 系统获得的定量相位图像中呈现出与动态跳动的心肌细胞相关的色散关系，即衰减率与空间模式的关系。
