Ebrahimi Samira, Moradi Ali-Reza, Anand Arun, Javidi Bahram
Opt Lett. 2014 May 15;39(10):2916-9. doi: 10.1364/OL.39.002916.
We present an integrated optical system for three-dimensional (3D) imaging of micrometer-sized samples, while immobilizing and manipulating the samples by means of an optical fiber trap. Optical traps allow us to apply and measure pico-Newton-sized forces, and perform detailed measurements of micrometer-sized dielectric systems in the field of biology. The integrated 3D system can be used as a major tool in the field of biophysics. The trap is built using a tapered optical fiber to enhance the effective numerical aperture of the fiber. The trapping system is mounted on a conventional microscope, in which the two eyepieces' output ports are used as the paths of an off-axis self-referencing digital holographic microscopy (DHM) setup. The trap is calibrated using a high-speed camera, and trap stiffness is determined through the power spectrum method. The compact setup provides an elegant apparatus for temporally stable DHM for 3D imaging of optically controlled samples. Three-dimensional information and quantitative phase contrast images of the trapped samples are obtained by postprocessing the recorded digital holograms. Experiments were performed on lipids and red blood cells. Quantitative phase contrast images and temporal evolution of optical thickness of trapped samples are presented.
我们展示了一种用于微米级样品三维（3D）成像的集成光学系统，同时借助光纤阱固定和操纵样品。光学阱使我们能够施加和测量皮牛顿级的力，并对生物学领域中的微米级介电系统进行详细测量。该集成3D系统可作为生物物理学领域的主要工具。该阱是通过使用锥形光纤构建的，以提高光纤的有效数值孔径。捕获系统安装在传统显微镜上，其中两个目镜的输出端口用作离轴自参考数字全息显微镜（DHM）装置的光路。使用高速相机对阱进行校准，并通过功率谱方法确定阱的刚度。这种紧凑的设置为光学控制样品的3D成像提供了一种用于时间稳定DHM的优雅装置。通过对记录的数字全息图进行后处理，获得了被捕获样品的三维信息和定量相衬图像。对脂质和红细胞进行了实验。展示了被捕获样品的定量相衬图像和光学厚度的时间演变。
