Capasso's [1] group has been working on projects like this for a couple of decades. It falls within the realm of work on metasurfaces. At a high level you can consider the silicon working in a sub wavelength regime, so that the optics interacts with an effective material which is engineered by changing the geometry of the sub wavelength features. They recently launched a startup [2] to commercialise the developed capabilities.

[1] https://scholar.google.com/citations?user=CmpEzW8AAAAJ

[2] https://www.metalenz.com/