Ge Baoliang, Zhou Renjie, Takiguchi Yu, Yaqoob Zahid, So Peter T C
Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge, MA 02139, USA, Department of Biological Engineering Massachusetts Institute of Technology Cambridge, MA 02139, USA, Laser Biomedical Research Center Massachusetts Institute of Technology Cambridge, MA 02139, USA.
Department of Biomedical Engineering The Chinese University of Hong Kong Shatin, New Territories, Hong Kong SAR, China,
Laser Photon Rev. 2018 Aug;12(8). doi: 10.1002/lpor.201800070. Epub 2018 Jun 10.
Optical anisotropy measurement is essential for material characterization and biological imaging. In order to achieve single-shot mapping of the birefringence parameters of anisotropic samples, a novel polarized light imaging concept is proposed, namely quantitative polarization interference microscopy (QPIM). QPIM can be realized through designing a compact polarization-resolved interference microscopy system that captures interferograms bearing sample's linear birefringence information. To extract the retardance and the orientation angle maps from a single-shot measurement, a mathematical model for QPIM is further developed. The QPIM system is validated by measuring a calibrated quarter-wave plate, whose fast-axis orientation angle and retardance are determined with great accuracies. The single-shot nature of QPIM further allows to measure the transient dynamics of birefringence changes in material containing anisotropic structures. This application is demonstrated by capturing transient retardance changes in a custom-designed parallel-aligned nematic liquid crystal-based device.
光学各向异性测量对于材料表征和生物成像至关重要。为了实现对各向异性样品双折射参数的单次映射，提出了一种新颖的偏振光成像概念，即定量偏振干涉显微镜（QPIM）。通过设计一个紧凑的偏振分辨干涉显微镜系统来实现QPIM，该系统可捕获承载样品线性双折射信息的干涉图。为了从单次测量中提取相位延迟和取向角图，进一步开发了QPIM的数学模型。通过测量校准后的四分之一波片对QPIM系统进行了验证，其快轴取向角和相位延迟的测定精度很高。QPIM的单次测量特性还允许测量含有各向异性结构材料中双折射变化的瞬态动力学。通过捕获定制设计的基于平行排列向列相液晶的器件中的瞬态相位延迟变化，展示了这一应用。
