Enhancing sensitivity of photoinduced molecular reorientation of oligothiophene-doped liquid crystals irradiated with a collimated laser beam

Liquid crystals (LCs) have been utilized for the innovative optical devices because the molecular reorientation triggers a change in their optical properties. Among them, oligothiophene-doped LCs can induce the molecular reorientation by irradiation with a laser beam, which is useful for all-optical devices. However, the photoinduced reorientational behavior was observed only by irradiation with a high-intensity laser beam. In this study, we investigated the effect of incident light properties on photoresponsive behavior of oligothiophene-doped LCs by irradiation with a collimated laser beam from the perspective of improvement of the photoresponsive sensitivity of the molecular reorientation. As a result, the irradiation of oligothiophene-doped LCs with a collimated laser beam enhanced the sensitivity of the molecular reorientation.