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Full-Text Articles in Physics

Multispectrum, Spatially Addressable Polarization Interference Filter, Salman Saeed, Philip Bos Jan 2002

Multispectrum, Spatially Addressable Polarization Interference Filter, Salman Saeed, Philip Bos

Philip J. Bos

We review current synthesis techniques for generating and improving birefringent filters. The relationship between wave-plate orientation and the resulting spectral output is shown to be that of a simple Fourier transform. By using this relationship and starting from the fan Sole configuration, we easily generated plate orientations providing lower sidelobe levels and improved finesse. We outline a method by which filters can be constructed to provide from 0 to 100% of the desired passband in a continuous fashion. Such a filter can be stacked to allow rapid control of any number of passbands and is shown, as an example in …


Effects Of Low Polymer Content In A Liquid-Crystal Microlens, Toshiaki Nose, Shin Masuda, Susumu Sato, Jianlin Li, Liang-Chy Chien, Philip J. Bos Mar 1997

Effects Of Low Polymer Content In A Liquid-Crystal Microlens, Toshiaki Nose, Shin Masuda, Susumu Sato, Jianlin Li, Liang-Chy Chien, Philip J. Bos

Philip J. Bos

A small number of bifunctional monomers are mixed with a nematic liquid crystal (LC) and cured with a distributed electric field, which is produced by a circular-hole-patterned electrode structure. A gradient type of lens, that is, a LC microlens, is investigated for various polymer concentrations. Addition of 3% polymer is enough to freeze the gradient-index properties of the structure in the form of a convex lens, and a polymer-stabilized LC microlens is demonstrated. Although a lower concentration of polymer cannot hold the distribution properties in a curing process, it can maintain the variable focus as a nematic material can. The …


Direct Nmr Observation Of Rotational Freeze-Out In The Smectic C-Phase, Demetri J. Photinos, Philip J. Bos, Mary E. Neubert, J. William Doane May 1981

Direct Nmr Observation Of Rotational Freeze-Out In The Smectic C-Phase, Demetri J. Photinos, Philip J. Bos, Mary E. Neubert, J. William Doane

Philip J. Bos

We report here a simple and direct observation that the molecular long axis is not, on the average, a rotation axis for the entire molecule in the smectic C phase (rotational freeze-out). This observation is made in the compound 4-n-heptyl-d15-oxybenzoic acid-d1 where experiment clearly shows that the principal axes of the time-averaged deuterium quadrupole interactions at specific sites of the hydrocarbon chain are not all parallel, demonstrating that they do not share a common axis of rotation.