Lu Xinghai

Improvement of Response Performance of Liquid Crystal Optical Devices by using a Low Viscosity Component

Difluorooxymethylene-bridged (CF2O) liquid crystal (LC) with low viscosity is prepared and used as a fast response LC material. When the material is mixed with isothiocyanato LCs with high birefringence, the viscoelastic coefficient of the mixture decreases evidently and, accordingly, the response performance increases. While the concentration of CF2O LCs is about 7%, the LC mixture approximately maintains high birefringence and exhibits a fastest response performance that is 14% higher than that of pure isothiocyanato LCs. Therefore, the LC material and mixing method could find useful applications in optical devices.

Advancement of adaptive optics in astronomical observation

Adaptive optics is used to compensate the atmospheric turbulence aberration for diffractive limit images, which makes the angular resolution of large aperture telescope not limited by the seeing or atmospheric coherence length. The continuous improvements of wavefront sensing, correctors and enlarged FOV for adaptive optics accelerate the development of astronomy. The main adaptive optics techniques include classical FOV and high resolution astronomical observation, extro-planet observation and solar observations and so on. And they have different technique requirements for adaptive optics. In the paper, we give some summarization and expectation of the advancement in the above three fields, especially in some new elemental techniques in detail, which will be helpful for our national adaptive optics development in large aperture telescopes.