We developed a new theory-based azimuthal phase retardation microscope to visualize distributions of actin filaments in biological cells without having them with exogenous dyes, fluorescence labels, or stains. The azimuthal phase retardation microscope visualizes distributions of actin filaments by measuring the intensity variations of each pixel of a charge coupled device camera while rotating...

Phase retardation of in vivo human retinal nerve fiber layer (RNFL) is quantitatively measured by two methods--polarization-sensitive spectral-domain optical coherence tomography (PS-SD-OCT) and scanning laser polarimetry (SLP). An en face cumulative phase retardation map is calculated from the three-dimensional (3-D) phase retardation volume of healthy and glaucomatous eyes measured by PS-SD-O...

purpose of study : the present research was carried out to study the prevalence of mental retardation among the youth and children of savojbolagh region, and to study its probable causes. method: the study comprised two phases. in the first phase, 1229 girls and boys, aged 5 to 18, were selected from among the children and youth of the urban and rural areas of savojbolagh, through cluster sampl...

Phase retardation imaging including local birefringence imaging of biological tissues is described by generalized Jones-matrix optical coherence tomography. The polarization properties of a local tissue can be obtained from two Jones matrices that are measured by backscattered lights from the front and back boundaries of the local tissue. The error in the phase retardation measurement due to ba...

A new method for simultaneously measuring the phase retardation and optic axis of a uniaxial compensation film is demonstrated using an axially-symmetric sheared polymer network liquid crystal (SPNLC). By overlaying a tested compensation film with a calibrated SPNLC cell between crossed polarizers, two dark spots are clearly observed in a CCD image. From the orientation direction and distance o...

This paper reports estimates of the prevalence of mental retardation and associated factors based on a population survey of 2- to 9-year-old children in Greater Karachi, Pakistan. A two-phase survey was implemented during the years 1988-1989. In the first phase, a cluster sample of 6,365 children (5,748 from urban areas and 617 from rural areas) was screened for disabilities using a parental re...

Phase-contrast microscopy is one of the most common and convenient imaging modalities to observe long-term multi-cellular processes, which generates images by the interference of lights passing through transparent specimens and background medium with different retarded phases. Despite many years of study, computer-aided phase contrast microscopy analysis on cell behavior is challenged by image ...

We demonstrate an in-line polarization controller based on a hollow optical fiber filled with a nematic liquid crystal by fabricating thin-film electrodes on the cladding of a fiber. The polarization controller consists of three control sections with fixed optic axes, which operate as phase retarders. The phase retardation in each section is controlled by the magnitude of the applied electric f...