Visualization of the optical spin Hall effect in out-of-plane refraction

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Metamaterials

Background:

• The traditional law of refraction defines an incidence plane based on the incident beam's wavevector and surface normal.
• The optical spin Hall effect (OSHE) describes a spin-dependent transverse shift of the refracted beam, occurring perpendicular to this incidence plane.

Purpose of the Study:

• To demonstrate and visualize the OSHE in out-of-plane refraction.
• To show that OSHE can be detected even at small and normal incidence angles.
• To explore the manipulation of spin-dependent photon spatial separation using metasurfaces.

Main Methods:

• Experimental investigation of out-of-plane refraction.
• Utilizing metasurfaces to control 2D additive momentum.
• Far-field detection and visualization techniques.

Main Results:

• Successful detection and visualization of OSHE in out-of-plane refraction.
• Demonstration of OSHE at small and normal incidence angles.
• Customization of photon spatial separation by manipulating metasurface momentum.

Conclusions:

• OSHE can occur and be observed in out-of-plane refraction.
• Metasurfaces offer a method to control the spin-dependent spatial separation of photons.
• A new plane is proposed to describe OSHE of refracted beams outside the traditional incidence plane.