Image quality enhancement of transparent waveguide display using a twisted nematic mode polymer-stabilized liquid crystal.

In this study, a twisted nematic mode polymer-stabilized liquid crystal (TN mode PSLC) integrated with a crossed polarizer was used to create a transparent waveguide display. When a voltage was applied, the PSLC scattered the waveguide light with a high polarization selectivity such that no substantial loss of the outgoing light intensity was observed after integrating the polarizer. However, with a crossed polarizer, in the ON state, the background light was not only scattered but also absorbed by the analyzer.

Electrotunable 180° achromatic linear polarization rotator based on a dual-frequency liquid crystal.

Linear polarization rotators have been widely used in optical systems. Commonly used polarization rotators are still beset by strong dispersion and thus restricted spectral bandwidth of operation. This leads to the development of achromatic or broadband alternatives, but most of them incorporate multiple waveplates for retardation compensation, which comes at the cost of increased complexity and reduced flexibility in operation and system design.

Smart Window with Active-Passive Hybrid Control.

Dimming and scattering control are two of the major features of smart windows, which provide adjustable sunlight intensity and protect the privacy of people in a building. A hybrid photo- and electrical-controllable smart window that exploits salt and photochromic dichroic dye-doped cholesteric liquid crystal was developed. The photochromic dichroic dye causes a change in transmittance from high to low upon exposure to sunlight.

Bistable cholesteric liquid crystal light shutter with multielectrode driving.

An electrically activated bistable light shutter that exploits polymer-stabilized cholesteric liquid crystal film was developed. Under double-sided three-terminal electrode driving, the device can be bistable and switched between focal conic and homeotropic textures with a uniform in-plane and vertical electrical field. The transparent state with a transmittance of 80% and the opaque/scattering state with a transmittance of 13% can be realized without any optical compensation film, and each can be simply switched to the other by applying a pulse voltage.