Generation of nondiffracting radial carpet-lattice beams by using an extended Durnin’s setup

In the past, the researchers have generated radial carpet beams, a type of 2D optical lattice with polar symmetry. However, the classical radial carpet beams expand slowly as they propagate, that is, they are not nondiffracting beams. By introducing an extended Durnin’s experimental setup equipped with an amplitude-type spatial light modulator loaded with the angular spectrum of a radial grating function, which is distributed along narrow annular pupils, we generated and demonstrated a type of nondiffracting radial carpet-lattice beam. Different from classical radial carpet beams that slowly expand during propagation, the generated nondiffracting radial carpet-lattice beams are propagation-invariant, hence termed nondiffracting radial carpet-lattice beams.