Spatial self-phase modulation with tunable dynamic process and its applications in all-optical nonlinear photonic devices

Abstract

In the spatial self-phase modulation (SSPM) experiments, the gravity-promoted thermal convection effect will lead to the distortion of self-diffraction ring in the evolution process. Generally, this distorted diffraction ring affects the SSPM applications in nonlinear photonic devices. In this work, for the first time to our knowledge, we use a cylindrical lens (CL) focusing laser beam to study the SSPM effect of black phosphorus (BP) suspensions. By adjusting the orientation angle θ between the CL's axis and the vertical direction, so as to change the effective area of thermal convection, we experimentally demonstrate the SSPM behavior with tunable dynamic process. As the angle θ increases from 0° to 90°, that is, the effective area of thermal convection becomes larger, we find that the formation times of complete symmetric diffraction ring and distorted diffraction ring become shorter and longer, respectively. In addition, based on the spatial cross-phase modulation (SXPM) of the CL focusing laser beam, we realize the all-optical switch and all-optical information converter that can relatively control the response time.