The invention provides an imaging system comprising an optical element for deflecting axially incident light into a series of axially spaced outward radial projections, and further comprising an image collection means for collecting reflected light. The element comprises a plurality of light deflecting surfaces or features which are arranged at axially successive points along the element, each at a different radial location. The light-deflecting surfaces are arranged to deflect light incident upon them from an axial direction in a radial direction, each thereby generating a radial projection of light from the element. A beam or beam bundle projected along the element has successive outer annular layers stripped by the facets and deflected outwards at different axial points along the structure.
