Phase retarders usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-wave plate. This wave plate is made from six birefringent quartz plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic wave plate demonstrates a huge freq...

background and purpose: birth of a mentally retarded child is a significant challenge in every family and is associated with the possibility of parental stress and depression. this study aimed to evaluate the self-concept of mothers with educable mentally retarded (emr) children. methods: this cross-sectional study was conducted on 40 mothers with emr children in the only special primary school...

PURPOSE To investigate a depolarizing layer that is visible in polarization-sensitive optical coherence tomography (PS-OCT) images of the retina. To identify this layer and characterize its depolarizing effect quantitatively. METHODS Ten healthy human subjects (mean age, 31 +/- 8 years) and two patients with RPE diseases participated in the study. The macular region of one eye of each subject...

Naturally occurring radon in ground water can potentially be used as an in situ partitioning tracer to characterize dense nonaqueous phase liquid (DNAPL) saturations. The static method involves comparing radon concentrations in water samples from DNAPL-contaminated and noncontaminated portions of an aquifer, while the push-pull method involves the injection (push) and extraction (pull) of a rad...

Using a functional renormalization-group method, we obtain the phase diagram of the two-leg ladder system within the Holstein-Hubbard model, which includes both electron-electron and electron-phonon interactions. Our renormalization-group technique allows us to analyze the problem for both weak and strong electronphonon couplings. We show that, in contrast to results from conventional weak-coup...

The gap of a planar-aligned liquid crystal (LC) cell is measured by a novel method: Monitoring the change in output wavelength of an external-cavity diode laser by varying the voltage driving the LC cell placed in the laser cavity. This method is particularly suitable for measurement of LC cells of small phase retardation. Measurement errors of +/-0.5 % and +/-0.6 % for 9.6-microm and 4.25-micr...

We propose a novel microscopy image restoration algorithm capable of co-restoring Phase Contrast and Differential Interference Contrast (DIC) microscopy images captured on the same cell dish simultaneously. Cells with different phase retardation and DIC gradient signals are restored into a single image without the halo artifact from phase contrast or pseudo 3D shadow-casting effect from DIC. Th...

PURPOSE We present a polarization-sensitive optical detection platform for label-free quantitative optical biosensing diagnosis using liquid crystals (LCs). This is capable of determining quantitatively the optical birefringence of optical cells containing LCs, whose orientation depends on the immobilized biomolecules. PATIENTS AND METHODS This technique uses a polarization-dependent double-p...

In the present paper, impact of small Fermi energy on selected parameters superconducting state in Ba$_{1-x}$K$_{x}$BiO$_{3}$ (BKBO) is studied at $x \in (0.3, 0.4, 0.5)$. This done by employing adiabatic and non-adiabatic Eliashberg equations context available experimental data. It found that retardation, strong-coupling effects notably influence phase BKBO. particular, electron-electron inter...