A quartic phase retardation function is described that reduces the variation of the intensity of the focal point of incoherent imaging systems suffering from primary third-order aberrations limited to coma and astigmatism. Corresponding modulation transfer functions are shown to remain practically invariant for moderate amounts of coma and astigmatism.

Performance of two types of differential interference contrast objectives, i.e., the XOR pattern and the zone-plate doublet, is quantitatively characterized and compared using modulation transfer function. Effects of partial coherence, finite absorption and phase in a complex object, as well as bias retardation are also examined.

Inhomogeneous polymer-dispersed liquid crystal devices having gradient droplet distribution were fabricated and their phase retardation characterized. The gradient refractive index profile can be used as switchable prism gratings, and positive and negative lenses with tunable focal lengths. Such a tunable electronic lens is a broadband device and can be used for unpolarized light. © 2002 Americ...

Basic understandings on the concept of geometric phase, also known as Pancharatnam – Berry and its application to creation photonic liquid crystal devices thin-films photoaligned nematic crystals are presented. The significance strong azimuthal anchoring energy role birefringence in photoalignment layer for formation phase gradients shown. dependence retardation circular polarised light passing...

What is believed to be a novel phase-sensitive optical heterodyne interferometric ellipsometer is set up to characterize a twisted-nematic liquid crystal (TN-LC) by the elliptical parameters of the output polarization state. This ellipsometer presents the advantages of both polarized optical heterodyne interferometry and optical photometry, which introduce a polarization modulation that is capa...

We study the electro-optic properties of subwavelength-pitch deformed-helix ferroelectric liquid crystals (DHFLC) illuminated with unpolarized light. In the experimental setup based on the Mach-Zehnder interferometer, it was observed that the reference and the sample beams being both unpolarized produce the interference pattern which is insensitive to rotation of in-plane optical axes of the DH...

Fragile X syndrome is an X-linked form of mental retardation resulting from the absence of expression of the fragile X mental retardation 1 gene. The encoded protein is a ribosome-associated, RNA-binding protein thought to play a role in translational regulation of selective messenger RNA transcripts. A knockout mouse has been described that exhibits subtle deficits in spatial learning but norm...

Using a modified random arbitrarily primed PCR approach, the operon encoding the Enterococcus faecalis JH2-2 CroRS two-component regulatory system was shown to be repressed during stationary phase, and a CroRS-regulated operon (glnQHMP) was identified. Gel retardation assays showed that the CroR regulator binds specifically to the glnQHMP promoter.