Photonic spin splitting with orbital angular momentum pointer states via modified weak measurement

We report an experimental demonstration of generalized photonic spin splitting (PSS) using arbitrary linearly polarized higher-order orbital angular momentum (OAM) pointer states supported by a modified weak measurement model. The experimental findings show the dependence of longitudinal and transverse PSS on linear polarization angle, postselection angle, and azimuthal index ($l$) of OAM states. PSS rises as $l$ increases, reaching a maximum of roughly 300 $\textmu{}\text{m}$ and 120 $\textmu{}\text{m}$ for the transverse and longitudinal shift values, respectively. Considering $l=0$, 1, and 2, the polarization-controlled variation of both shifts at three distinct angles of incidence is investigated for a fixed postselection angle. All the experimental results agree well with the developed theoretical model, proving the model's accuracy. This model is valid for both external and internal reflection of arbitrary linearly polarized incident light reflecting from absorbing as well as nonabsorbing mediums, considering arbitrary coupling strength and a very small postselection angle. The manipulation of PSS using higher-order OAM light beams shown in this study will have a wide range of applications in wavefront manipulation, optical sensors, and nanophotonics.