Metallens
Metallens, more commonly called a metalens or metasurface lens, is a flat optical element that focuses light using a two-dimensional array of subwavelength nanostructures. Rather than relying on gradual phase accumulation in bulk glass, a metalens manipulates the phase, amplitude, and sometimes polarization of incident light at each nanoscale site to reproduce a desired wavefront.
Principle of operation: Each nanopillar or nanoantenna acts as a local optical element that shifts the phase
Materials and fabrication: Early metalenses often used plasmonic metals such as gold or silver, but high losses
Advantages and challenges: Metalenses are ultrathin and lightweight, with the potential for camera miniaturization and integration
Applications and outlook: Potential uses include smartphone and aerospace imaging, augmented and virtual reality optics, microscopy,