Papers by Author: Qiang Hua Li

Abstract: The effect of magnetic fields on the molecular configuration of liquid crystalline polymers (LCPs) under simple shear flows is numerically simulated using the Doi theory when the initial state of the director is out-of-plane. A method of effectively enhance the order parameter is discussed in this paper. The simulation results show that the degree of molecular alignment can be greatly increased along the direction of the magnetic field. It is an efficient way to improve the performance of LCP materials.

Abstract: The reflectivity and transmission spectra will be discussed in an antiferromagnetic (AF) sandwich structure as ZnF₂/MnF₂/SiO₂. Such geometry is used, where the AF anisotropy axis and external static magnetic field both are parallel to the film surfaces and normal to the incident plane. The results show that the reflectivity and transmission spectra can be governed by the incident angles and the AF thickness.

Abstract: A FBG fast demodulation system with close loop control is presented. Based on filter edge, the demodulation speed is very high. The system overcomes the strict command on matched FBG fabrication and eliminates the temperature induced error. With close loop control, the temperature induced FBG wavelength shift is compensated well.