Dual-mode polarization-sensitive tunable metalens enabling Bright-Field and Edge-Enhanced imaging

Metalenses exhibit significant potential in various fields due to their ability to access comprehensive, complex information. The ability to integrate multiple features into a single device, along with its compact and efficient design, allows for the creation of miniature microscopy systems that showcase remarkable performance. By applying unique design techniques, we have developed and implemented polarization-dependent metalens. This metalens makes smooth transitions between edge enhancement imaging and bright field imaging possible. Employing the principles of geometric phase, we design a dual mode metalens by using hydrogenated amorphous silicon to physically manifest the necessary phase profiles for operation in the visible spectrum. These profiles contain a conventional hyperbolic configuration intended for bright-field imaging, along with spiral metalens with a topological charge of +1, tailored for edge-enhanced imaging functions. When utilizing Left Circular Polarization (LCP), our designed lens enables bright field imaging. Conversely, Right Circular Polarization (RCP) facilitates image edge enhancement. We showcase through numerical demonstration the metalens capability to focus and generate vortices under various states of circular polarization and validate its potential for diverse applications.