Transient optically induced grating and underlying transport process in bent-core nematics

Abstract

In this paper, we have applied a holographic time-of-flight technique with a nanosecond laser pulse to perform time-resolved measurements of optically induced gratings in bent-core nematics formed by a new kind of liquid crystal (LC). The effects of the electric field, laser pulse energy, temperature, and light intensity pattern on the photocharge transport process were investigated systematically. The results indicate that some peculiar features, such as high photosensitivity, relatively large mobility, and negative conductivity anisotropy, were present in the studied soft-matter system. Furthermore, a coupling between the optically induced grating and electrically induced convection was observed, which revealed a competitive state between them via the transport process. Thus, a better understanding of the carrier transport process involving photosensitivity and response time will help to tailor LC devices toward novel optical applications.