"Meta-lens" researches has drawn lots of attentions in recently years. With many contributions from groups with nanotechnology backgrounds, meta-lens are realized by creating a focusing wavefront using structured surfaces like plasmonic structures and high index dielectric structures. However, compared to the overwhelming attentions it got, the drawbacks of such meta-lens from optics perspective are greatly overlooked, similar to the fact that the losses of plasmonic structures are neglected in many publications which produce lots of highly cited papers and create a "closed" subfield of physics but not many real applications comes out.
Finally a nice and critical review is given by diffraction optics experts P. Lalanne and P. Chavel on the current "Meta-lens" researches.
https://arxiv.org/ftp/arxiv/papers/1610/1610.02507.pdf
