Physics Commons^™

A Dual-Functionality Metalens To Shape A Circularly Polarized Optical Vortex Or A Second-Order Cylindrical Vector Beam, Victor V, Kotlyar, Sergey S. Stafeey, Anton G. Nalimov, Liam O'Faolain, Maria V. Kotlyar

Cappa Publications

Using e-beam lithography and reactive ion beam etching of a 120 nm amorphous silicon film, we fabricate a 30-µm spiral metalens that has a very short focal length that is equal to the incident 633 nm wavelength (numerical aperture about 1) and is composed of 16-sectored subwavelength binary gratings with a 220 nm period. Its unique feature is that the metalens generates a left-hand circularly polarized optical vortex with topological charge 2 when illuminated by a left-hand circularly polarized light but generates a cylindrical second-order vector beam when illuminated by linearly polarized light. Both for linearly and circularly polarized light, …