Geometric interpretation of radiation pressure

When light, or electromagnetic radiation, impacts a surface, it generates a force known as radiation pressure. In this study, we explore the radiation pressure generated by a finite, structured light beams and how it differs from that of a plane wave at an identical frequency. A notable characteristic of structured beams, especially as they pass through their focal point, is the accumulation of an extra phase shift, unlike a plane wave traveling the same distance. This phenomenon, known as the Gouy phase, underpins the difference in radiation pressure that we observe. One case we focus on is for Laguerre-Gaussian modes, and we detail specific experimental approaches to quantify the variance in radiation pressure, which amounts to approximately 20fN/W for each unit of orbital angular momentum.