Laser-addressed liquid crystal light valve with dichroic dye added as a laser beam absorber

Abstract

A novel laseraddressed smectic liquidcrystal light valve

Non‐Chiral Smectic Liquid Crystals: Nonchiral Smectic Liquid Crystals — Applications

“…In the earlier work with YAG lasers, line widths of 15-20 pm were typical [6, 28, 351 (25 line pairdmm), while in later work, line widths down to 3 pm have been reported [23] in 9 pm thick films using a 12 mW He -Ne laser and a dye dissolved in the liquid crystal. However, 10 pm line widths are more typical [29].…”

“…A thin layer, typically 12-14 pm, of SmA liquid crystal is sandwiched between two homeotropically [23] aligned glass plates to produce a transparent single crystal film ( Fig. 2).…”

“…Initially, the dye was incorporated into a 1 ym thickpolymer film [36] (often polyimide), spin-coated onto the I T 0 electrodes; this was not without its problems, as the resistive polymer layer dictated that a higher voltage was required to cause dielectric reorientation of the smectic phase. It was also calculated that if the dye could be dissolved in the liquid crystal itself, rather than coated onto the substrate, the efficiency could almost be doubled [37] and the line width reduced; a large proportion of the heat generated is dissipated into the substrate and wasted in heating the substrate, rather than the liquid crystal film, and causing line broadening [23]. However, when traditional dyes were tested it was found that they had poor solubility in the liquid crystal and poor stability; the first attempts were abandoned.…”

Modes for Liquid Crystal Devices

“…(ii) Dyes improve also the writing speed by absorbing effectively the energy of the laser beam [96]. (iii) With dye addition, the resolution of the display can be improved by suppressing heat diffusion to the surroundings, since the light absorption is concentrated to the dyes added [97]. Thus, by incorporating dyes, new features and various improved characteristics can be expected.…”