Coherent manipulation of light dragging in a moving microcavity using tunable dispersion in an atomic medium

Abstract

The Fresnel light dragging effect has remained a subject of significant interest for over two centuries, describing the modification of light propagation in a moving medium. This effect is strongly influenced by the dispersive properties of the medium and is commonly manifested through the phase shift of transmitted light, which varies with the velocity of the medium. In this work, we investigate the phase shift induced by varying the velocity of a moving microcavity. Our results show that a phase shift of approximately 10 m rad is obtained at a velocity of 2 m/s, which increases to about 40 m rad as the velocity reaches 10 m/s. Additionally, the motion of the microcavity significantly affects the transmission of the probe field, leading to measurable perturbations that depend on the induced phase shift. Specifically, the perturbation increases from 0.004 at 2 m/s to 0.02 at 10 m/s. These findings demonstrate that increasing the velocity of the medium enhances the light dragging effect, resulting in a greater modification of light propagation compared to its behavior in a vacuum. This study provides valuable insight into the control of light–matter interaction in dynamic optical systems and its potential applications in advanced photonic technologies.