Highly Efficient Air?Mode Silicon Metasurfaces for Visible Light Operation Embedded in a Protective Silica Layer

Dielectric metasurfaces have significant potential for delivering miniaturized optical systems with versatile functionalities, leading to applications in various fields such as orbital angular momentum generation, imaging, and holography. Among the different materials, crystalline silicon has advantage of technological maturity high refractive index, which increases design flexibility processing latitude. The second, often overlooked, is that it affords embedding metasurface a protective material silica, essential practical applications. trade-off against this index silicon's absorption at visible wavelength, requires new strategies. Here, strategy based on supporting air modes identified can lead transmission efficiency 87% wavelength 532 nm. This exceptional obtained by using confine electric field periphery meta-atoms, thereby reducing losses. As an example, fully embedded described generate vortex beams orders momentum. It envisioned proposed paves way high-efficiency silicon.