线扫描虚拟结构调制共聚焦显微成像

共聚焦显微镜的分辨率受光学衍射极限限制。已经证明结构调制在共聚焦显微镜中可以实现超分辨成像,但是由于图像采集速度有限,导致该方法的实际应用具有局限性。为了提高系统的成像速度,本文介绍了一种将线扫描应用到结构调制共焦显微镜的方法。利用柱面透镜产生线照明,余弦数字掩模用于探测端的解扫描线斑图像调制,与虚拟结构探测方法不同之处在于无需后续的移频过程。为了提高各项同性分辨率,采用样本转动的方式实现0°、90°两角度扫描。仿真和实验结果表明,相干传递函数频谱宽度增大,成像分辨率达到传统共聚焦显微镜的1.4倍。与采集单点图像的结构调制共焦显微镜相比,图像采集速度提高了104倍。

Line-scanning confocal microscopic imaging based on virtual structured modulation

Resolution in a confocal microscope is limited by the diffraction limit.Structured modulation has been proven to be able to achieve super-resolution in confocal microscopy,however,its limited speed in image acquisition limits its applicability in practical applications.In order to improve its imaging speed,we introduce a method that can achieve rapid super-resolution confocal microscopy by combining line-scanning and structured detection.A cylindrical lens is used to focus the light into a line,and a digital mask with a sinusoidal function is used to modulate the descanned image in the light detection arm.Unlike the virtual structured method,there is no need for a subsequent frequency shift process.In order to improve the isotropic resolution of the system,a scanning angle of 0°and 90°is achieved by rotating the sample.Simulation and experiment results indicate that the spectrum width of coherent transfer function expands and the resolution is 1.4 times as large as that of a conventional confocal microscope.This method increases the system’s imaging acquisition speed 104-fold when compared with a confocal structured modulation microscope that uses spotscanning.