Demonstration of Subluminal and Superluminal Group Velocities of Diffraction-Free Space-Time Light Sheets in Free Space

摘要

We report on an experimental study to control the group velocity of diffraction-free space-time light sheets propagating in free space. We demonstrate pulsed light sheets with speeds exceeding 30c and going below 0.5c. We also show space-time light sheets with negative group velocity.