The generation of a sub-diffraction longitudinally polarized spot is of great interest in various applications, such as optical tweezers, super-resolution microscopy, high-resolution Raman spectroscopy, and high-density optical data storage. Many theoretical investigations have been conducted into the tight focusing of a longitudinally polarized spot with high-numerical-aperture aplanatic lense...

OBJECTIVE To introduce the use of optical coherence tomography with an operating microscope for intra-operative evaluation of the human larynx. METHODS A specially equipped operating microscope with integrated spectral domain optical coherence tomography apparatus was used during microlaryngoscopy. RESULTS Technical improvements in optical coherence tomography equipment (e.g. pilot beam, va...

The Oligocene–Miocene deposits of the Asmari Formation are located in SW of the Zagros Mountains of Iran. The lower part of the Asmari Formation consists of an evaporite bed that is termed Basal Anhydrite. Seven sections from four different anticlines were selected and sampled for petrographic and mineralogical analyses .The petrographical examinations were carried out using an optical polarize...

By decomposing a linearly polarized light field in terms of plane waves, the elliptic intensity distribution across the focal spot is shown to be determined by the E-vector's longitudinal component. Considering that the Poynting vector's projection onto the optical axis (power flux) is independent of the E-vector's longitudinal component, the power flux cross section has a circular form. Using ...

Dispersions of colloidal particles in aqueous media are widely investigated because of their use in many industrial applications (foods, pharmaceuticals, cosmetics, paints, etc.). Acid-hydrolyzed chitin has been reported to spontaneously disperse into colloidal rod-like crystalline particles, which can form rigid structures. Such colloidal dispersions of acid-degraded chitin can undergo an isot...

In this article, we synthesized a type of DNA amphiphiles (called DNA-lipids) and systematically studied its assembly behavior at the liquid crystal (LC)-aqueous interface. It turned out that the pure DNA-lipids at various concentrations cannot trigger the optical transition of liquid crystals from planar anchoring to homeotropic anchoring at the liquid crystal-aqueous interface. The co-assembl...

We report an imaging method for fast, sensitive analysis of the orientation of fluorescent molecules by employing a liquid-crystal based universal polarizer in the optical path of a wide-field light microscope. We developed specific acquisition and processing algorithms for measuring the anisotropy and for correcting artifacts caused by fluorescence bleaching, background light, and differential...