Observing spin Hall effect of pseudo-thermal light through weak measurement

TL;DR

This paper investigates the spin Hall effect of partially coherent light beams using weak measurement, revealing that the observed dark strip results from overlapping coherent speckles rather than a simple statistical mixture.

Contribution

It provides a new understanding of SHEL in partially coherent beams by analyzing speckle overlap and develops a qualitative theory incorporating intensity distribution effects.

Findings

Dark strip in SHEL of PCB is due to speckle overlap.

Adjusting beam parameters affects SHEL observation.

Theory applies to Goos-Hänchen effect as well.

Abstract

It is well known that the spin Hall effect of light (SHEL) can be easily observed via weak measurement by the dark strip resulted from the splitting of different polarization components. We find that the SHEL of partially coherent beam (PCB) also has similar phenomenon. However, the existence of the dark strip in the SHEL of PCB can not be properly justified by considering the beam as a statistical assemble of coherent speckles. Also, the dark strip of PCB is not purely dark. By analyzing the autocorrelation of the central dark strip part of the SHEL of PCB, we show that SHEL of PCB is essentially the direct result of overlapping coherent speckles' SHEL. Then we further prove our conclusion by adjusting the converging level and the incident angle of the beam. Finally, we develop a qualitative theory by taking the intensity distribution of PCB into account, to fully clarify the SHEL of PCB. The feasibility of our theory to Goos-H\"anchen (GH) scenario is also demonstrated.