Research Of Electro-Optical Characteristics Of Blue Phase Liquid Crystal And Device Structure Using Blue Phase Liquid Crystal

Blue phases appear in chiral liquid crystals in a small temperaturerange between the chiral nematic phase and the isotropic one. The name"blue phase" originated from the blue reflection peak of bragg diffraction.Blue phase liquid crystal exhibits some evolutionary characteristics,including optical isotropy when no voltage is applied, bragg diffraction oflight in visible wavelength, exotic three dimensional self-assemblingstructures and fast response, so blue phase has promising application in thefield of LC display, field sequence display, LC lens and LC lasers.Standing in the way of any practical applications of blue phases is,obviously, the narrow temperature range at which they appear. Althoughthe unique characteristics of blue phases are very attractive, the narrowtemperature range at which they are available is only on the order of1Kelvin, which prohibits potential applications of blue phase. Recently,however, there have been some attempts, especially "polymerstabilization", to expand this narrow temperature range. It was reportedthat the temperature range of the blue phase can be expanded by severaltens of degrees Celsius, which has attracted researchers’ attention in thefield of display, optoelectronics and photonics.But there are still some obstacles such as high operating voltage,hysteresis, residual birefringence, and weak thermal stability. In order tosolve driving issue and improve device performance in LC display, botheffects of chiral dopant and polymerization on blue phase liquid crystal areinvestigated in this paper. Meanwhile, several novel display and optical devices using blue phase, including transflective display and blue phaseliquid crystal lens, are designed.