Clad photon sieve for generating localized hollow beams

• Photon sieve is proposed to generate localized hollow beams for the first time.
• Clad photon sieve has the property of focusing dark spots with super-resolution.
• The dark spot size and center intensity can be changed with design parameters.
• Plane wave illumination and Gaussian illumination are both feasible.
• The clad photon sieve is easy to be replicated and be arrayed as required.

A novel photon sieve structure called clad photon sieve is proposed to generate localized hollow beams and its design principle and focusing properties are studied. The clad photon sieve is composed of the internal zone and external zone with pinholes being positioned on the dark zones. Pinholes in the internal zone and in the external zone give destructive interference to the focus, leading to localized hollow beams being generated on the focal plane. Focusing properties of clad photon sieve with different focal lengths, zone numbers and modulation factors are also studied by theoretical calculations, numerical simulations and experiments, showing that the central dark spot size can be controlled by the focal length and rings number, and the intensity of the central dark spot varies with different modulation factors related with the internal zone and the external zone. This photon sieve can be useful for trapping and manipulating of particles and cooling of atoms.