Impact of laser polarization and angle of incidence on phase shifting efficacy of an all-optically addressed liquid crystal delay line at X band

Abstract

This article conducts an experimental investigation into the impact of laser polarization and angle of incidence on the efficiency of a liquid crystal enabled 0-180° phase shifting delay line operating at the X band. According to measurement results, the polarization of the laser beam with regard to the rubbing direction and the liquid crystal filling direction has a significant impact on the tuning efficacy of the delay line. The possible phase shift is increased when the laser beam is polarized parallel to both the liquid crystal filling direction and the rubbing direction. Furthermore, the effectiveness of the delay line's phase shifting is non-linearly influenced by the angle of incidence, as evidenced by another two experiments that were carried out with the laser source rotated at the same and diverse planes relative to the fixed rubbing alignment direction, respectively.