Flat lenses from Edmund Optics.

I've read about these somewhere else.

Polarization Directed Flat Lenses

Polarization Directed Flat Lenses function differently than typical spherical lenses. The focal length is defined by a holographically recorded wavefront profile, rather than by the curvature of the surfaces. Thus, the Polarization Directed Flat Lenses have less weight and volume than comparable spherical lenses, making them ideal for space-constrained applications. The Polarization Directed Flat Lenses are the result of exciting new design technology, allowing for endless possibilities across various industry fields and application types.

Optics - Imaging - Photonics - Optomechanics - Lasers | Edmund Optics