Nanointerferometric discrimination of the spin–orbit Hall effect

The interaction between light’s spin and orbital angular momentum under nonparaxial conditions not only facilitates many fundamental sciences but also underpins a variety of applications. Such a strong coupling between the two separable dimensions normally occurs when light propagates through nanoscale inhomogeneous media or under tight focusing. In this regard, subwavelength scrutinizing the spatial distribution of such light attributes is of utmost importance. Here, we demonstrate a nanointerferometric scheme to map light’s spin and orbital angular momentum with a subwavelength resolution via the interferometric scattering signal from a plasmonic nanohole. Further, we demonstrate the application of the nanointerferometric method to discrimination of spin–orbit Hall effect on the hybrid-order Poincaré sphere.