Transformation of photonic spin Hall effect from momentum space to position space

Photonic spin Hall effect (PSHE) in momentum space can lead to a giant spin-dependent splitting (SDS). However, the SDS in momentum space increases linearly with beam propagation distance, which limits its applications. In this work, a simple method is proposed to transform the PSHE from momentum space to position space. We first theoretically analyze the feasibility of the transformation. The results show that the transformation can be realized when a light wave passes through two identical Pancharatnam–Berry phase metasurfaces. Then an experimental setup is established to verify the theoretical results. Through rational design of the optical path, only one metasurface is needed to complete the transformation of PSHE from momentum space to position space. The experimental results agree well with theoretical calculations. We believe that these results are helpful for the design of photonics devices based on PSHE.