A refracting element having an associated focal plane, wherein the refracting element comprises a first surface, a central point, and a plurality of facets located on the first surface and arranged concentrically around the central point, characterised by: each facet having (i) a respective height that varies based on a distance from the central point, (ii) a respective variable width; (iii) an inner side and an outer side; and (iv) a respective variable facet angle, the respective variable facet angle being either positive or negative, wherein for a particular facet, the value of the facet angle is negative if the inner side of the facet is sloping, and the value of the facet angle is positive if the outer side is sloping, and wherein each facet has a respective surface such that the plurality of facets refract the focused radiation using prismatic effects, and one or more of the respective surfaces of the plurality of facets is an approximately flat surface (S-1, S-2), and the refracting element having a first facet of the plurality of facets having a positive facet angle adjacent to and joined with a second facet of the plurality of facets having a negative facet angle, such that the refracting element is configured to: receive the focused radiation; refract, using the prismatic effects of the plurality of facets, the focused radiation by changing an incoming beam profile of the electromagnetic radiation received through shifting a portion of the electromagnetic radiation received toward a periphery of the refracting element to produce refracted radiation having an annular pattern at the focal plane. each facet having (i) a respective height that varies based on a distance from the central point, (ii) a respective variable width; (iii) an inner side and an outer side; and (iv) a respective variable facet angle, the respective variable facet angle being either positive or negative, wherein for a particular facet, the value of the facet angle is negative if the inner side of the facet is sloping, and the value of the facet angle is positive if the outer side is sloping, and wherein each facet has a respective surface such that the plurality of facets refract the focused radiation using prismatic effects, and one or more of the respective surfaces of the plurality of facets is an approximately flat surface (S-1, S-2), and the refracting element having a first facet of the plurality of facets having a positive facet angle adjacent to and joined with a second facet of the plurality of facets having a negative facet angle, such that the refracting element is configured to: receive the focused radiation; refract, using the prismatic effects of the plurality of facets, the focused radiation by changing an incoming beam profile of the electromagnetic radiation received through shifting a portion of the electromagnetic radiation received toward a periphery of the refracting element to produce refracted radiation having an annular pattern at the focal plane. receive the focused radiation; refract, using the prismatic effects of the plurality of facets, the focused radiation by changing an incoming beam profile of the electromagnetic radiation received through shifting a portion of the electromagnetic radiation received toward a periphery of the refracting element to produce refracted radiation having an annular pattern at the focal plane.