Diffractive optical element and method of forming thereof

Abstract

There is provided a diffractive optical element including a substrate, and an array of optical nanoantennas arranged on the substrate, the array of optical nanoantennas being spaced apart periodically in a lateral direction for supporting a plurality of diffraction orders at a predetermined wavelength. In particular, each optical nanoantenna in the array of optical nanoantennas is configured to control distribution of electromagnetic energy from an incident light having the predetermined wavelength amongst the plurality of diffraction orders so as to promote scattering of the electromagnetic energy in at least a first direction and suppress scattering of the electromagnetic energy in at least a second direction, the first direction and the second direction corresponding to a first diffraction order and a second diffraction order of the plurality of diffraction orders, respectively. There also provided a corresponding method of forming the diffractive optical element and a flat optical element, such as a flat lens.