Dual-polarization cloud lidar using a liquid crystal variable retarder

2005 ◽  
Author(s):  
Nathan L. Seldomridge ◽  
Joseph A. Shaw ◽  
Kevin S. Repasky
Keyword(s):  
Liquid Crystal ◽  
Dual Polarization ◽  
Polarization Cloud

Dual-polarization lidar using a liquid crystal variable retarder

2006 ◽  
Vol 45 (10) ◽  
pp. 106202 ◽  
Author(s):  
Nathan L. Seldomridge
Keyword(s):  
Liquid Crystal ◽  
Dual Polarization

Freeze-fracture TEM of the helical smectic A* phase

1992 ◽  
Vol 50 (1) ◽  
pp. 278-279
Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski
Keyword(s):  
Liquid Crystal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Freeze Fracture ◽  
Smectic Phase ◽  
Layer Spacing ◽  
Screw Dislocations ◽  
Smectic A ◽  
Smectic Phases ◽  
Discrete Amount

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).

Attractive mode force microscopy of chiral liquid crystal surfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 268-269
Author(s):  
B.D. Terris ◽  
R. J. Twieg ◽  
C. Nguyen ◽  
G. Sigaud ◽  
H. T. Nguyen
Keyword(s):  
Liquid Crystal ◽  
Crystal Surfaces ◽  
Free Surfaces ◽  
Control Range ◽  
Force Microscopy ◽  
Liquid Crystal Films ◽  
Chiral Liquid Crystal ◽  
Crystal Films ◽  
Electrostatic Charging ◽  
And Shifts

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.

Development of liquid crystal light valves using Bi12SiO20 as the photoconductor. Part 2: Device performance

1986 ◽  
Vol 133 (1) ◽  
pp. 65
Author(s):  
W.L. Baillie ◽  
P.M. Openshaw ◽  
A.D. Hart ◽  
S.S. Makh
Keyword(s):  
Liquid Crystal ◽  
Device Performance
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