Inter-frequency all-optical transfer of structured light information in Rb vapor based on spatial cross-phase modulation

Abstract

High-dimensional all-optical information transfer facilitates large-capacity, high-speed, and energy-efficient optical communication, playing a pivotal role in advancing modern photonic technologies. Here, we demonstrate the all-optical transfer of structured information between two beams with different frequencies via spatial cross-phase modulation in a hot 85Rb vapor. A high-power pump beam, characterized by a structured light, induces a refractive index change in the rubidium vapor. A low-power, initially Gaussian probe beam counter-propagates through the rubidium vapor cell, undergoing a nonlinear phase shift induced by the pump beam. This enables the transfer of the spatial characteristics imprinted by the pump beam onto the probe beam with maximum structural integrity and similarity. The spatial evolution of the transverse intensity of the probe beam vs frequency detunings of the pump and probe beams, pump beam power, and cell temperature is studied. We have further shown that the structural similarity can be manipulated by changing the pump beam power and temperature of the vapor cell. Our findings may reveal a way to manipulate light fields, offering potential applications in optical communication, all-optical data processing, and advanced photonic devices.