Full-Stokes imaging polarimeter using an array of elliptical polarizer.

In this paper, a full-Stokes imaging polarimeter operating at 580 nm using an array of elliptical polarizers is presented. The division-of-focal-plane polarimeter utilizes a set of four optimized measurements which represent a regular tetrahedron inscribed in the Poincaré sphere. Results from the device fabrication, instrument calibration and characterization are presented. The performance of the optimized full Stokes polarimeter, as defined by size of the standard deviation of the degree of circular polarization, is found to be approximately five times better than the performance of the simple full-Stokes polarimeter.

Patterned cholesteric liquid crystal polymer film.

Herein, the ability to create arbitrarily patterned circular polarized optical devices is demonstrated by using cholesteric liquid crystal polymer. Photoalignment with polarized ultraviolet light is utilized to create aligned cholesteric liquid crystal films. Two different methods, thermal annealing and solvent rinse, are utilized for patterning cholesteric liquid crystal films over large areas. The patterned cholesteric liquid crystal films are measured using a Mueller matrix imaging polarimeter, and the polarization properties, including depolarization index, circular diattenuation (CD), and circular retardance are derived. Patterned nonlinearly polarized optical devices can be fabricated with feature sizes as small as 20 µm with a CD of 0.812±0.015. Circular polarizing filters based on polymer cholesteric liquid crystal films have applications in three-dimensional displays, medical imaging, polarimetry, and interferometry.

Liquid crystal polymer full-stokes division of focal plane polarimeter.

A division-of-focal-plane polarimeter based on a dichroic dye and liquid crystal polymer guest-host system is presented. Two Stokes polarimeters are demonstrated: a linear Stokes and the first ever Full-Stokes division-of-focal-plane polarimeter. The fabrication, packaging, and characterization of the systems are presented. Finally, optimized polarimeter designs are discussed for future works.

Multi-mode waveguides from ultra-long self-assembled hexagonal faceted microtubules of a benzothiadiazole molecule.

Length controlled (µm-mm-cm) self-assembly of hexagonal faceted microtubules has been achieved using a phase-transfer solution processing approach from . The self-assembled structures exhibit both polarized light emission and multi-mode waveguide properties over large length scales. The multi-mode waveguide characteristics are analyzed using a combination of experiment and finite-difference-time-domain calculations.

Patterned color liquid crystal polymer polarizers.

We demonstrate patterned polarizers for visible wavelengths using dichroic dye in a liquid crystal polymer (LCP) host. Contact lithography is used to pattern a thin alignment layer, which subsequently transfers the pattern to the LCP. A gray dichroic dye mixture for the visible spectrum is optimized and implemented along with LCP to fabricate this polarizer. A peak extinction ratio of 41 was measured at a 633 nm wavelength, while simultaneously showing patterns as small as 3 µm. Finally, multi layer films are demonstrated by fabricating a two layer patterned circular polarizer consisting of a quarter-wave retarder and a color polarizer. Our process has applications in three-dimensional displays, interferometry, optical storage, and polarimeters.

Imaging capability of patterned liquid crystals.

We demonstrate the ability to make high resolution arbitrary patterned optical retarders using liquid crystal polymer (LCP). Contact lithography is used to define unique LCP alignment domains. Patterned LCP retarders are imaged between crossed polarizers to determine pattern visibility as a function of feature size. It was determined that patterned retarders for wavelengths between 250 nm and 2500 nm can be constructed with feature sizes as small as 4 microm. We also showed that multiple patterns can be created on the same substrate using a combination of patterned LCP and opaque features. Our process has applications in displays, double-patterning lithography, and imaging polarimetry.