Cylindrical vector beam sorting with an asymmetrical Pancharatnam-Berry lens

As a type of orthogonal mode with intrinsic turbulence-resilient nature, the cylindrical vector beam (CVB) can offer an extra degree of freedom to increase the information capacity of the optical communications. The sorting of the CVBs is of vital importance for applications in space-division multiplexing communication. Here, we demonstrate numerically and experimentally a CVB sorting with only an asymmetrical Pancharatnam-Berry (PB) lens. The asymmetrical PB lens is composed of two semicircular PB lenses, and it is capable of sorting 11 CVB modes at a wavelength of 1550 nm. The incident CVB can be focused through the asymmetrical PB lens with a focal shift that proportional to the order of the CVB. The proposed sorting device is simple, elegant and efficient, and it may benefit the future applications in mode multiplexing communications.