COLLIMIZING METALINS AND LIGHTING DEVICE

Abstract

A collimating metalens (15) comprises a transparent substrate (100) with a first principal surface (101) and a second principal surface (102). The first and second principal surfaces (101, 102) are parallel to a first direction and a second direction, the first direction being perpendicular to the second direction. The collimating metalens (15) further comprises a first metasurface (108) formed on the first principal surface (101), the first metasurface (108) comprising a first region (111). The collimating metalens (15) further comprises a second metasurface (109) formed on the second principal surface (102), the second metasurface (109) comprising a second region (112). The first region (111) acts as a cylindrical concave lens, and the second region (112) acts as a convex lens.