光纤照明数字全息显微镜实验研究

Experimental Study of Digital Holographic Microscope with Optical Fiber Illumination

设计并组建了光纤照明的多分辨率数字全息显微镜系统。激光器出射的激光经光纤耦合器、光纤分束器,分别形成照明样品的照明光波和参考光波。照明光波经扩束准直后透过样品形成物光波,与参考光在图像传感器表面干涉形成全息图。相较于普通数字全息显微镜,该系统更加紧凑稳定,并且通过转动物镜转盘,可选择采用不同的显微物镜,实现多分辨率显微定量相位成像。对该系统进行了实验测试,首先用标准样品聚苯乙烯微球验证了该系统定量相位成像的准确性,并测量了系统的时空噪声,得到空间噪声在2 nm以内,时间噪声在0.8 nm以内;然后将系统应用于单模光纤、微光学元件和生物样品的测量,获得了准确的定量相位像。实验结果表明组建的光纤照明多分辨率光纤型数字全息显微镜稳定性高,能够实现准确的定量相位成像。

We design and establish a multi-resolution digital holographic microscope with optical fiber.The laser passes through the optical fiber coupler and the optical fiber splitter to form the illumination light wave and the reference light wave respectively.The illuminated light wave is collimated by expanding beam,then it passes through the sample to form object light wave.Compared with ordinary digital holographic microscope,the system is more compact and stable.And it can achieve multi-resolution quantitative phase imaging by choosing different microscopic objectives by rotating the lens turret.First,the imaging accuracy and the spatiotemporal noise of the system is measured.The imaging accuracy is verified by measuring polystyrene beads with the known parameters.The spatial noise is below 2 nm,and the temporal noise is below 0.8 nm.Then,the single-mode fiber,micro-optical elements and biological samples are measured and accurate quantitative phase images are obtained.The experimental results demonstrate that the digital holographic microscope with optical fiber illumination has high stability and can achieve accurate quantitative phase imaging.