kinoform

A kinoform is a type of computer-generated converging lens that is able to efficiently focus light to a point.{{cite journal | last=Jordan | first=J. A. | last2=Hirsch | first2=P. M. | last3=Lesem | first3=L. B. | last4=Van Rooy | first4=D. L. | title=Kinoform Lenses | journal=Applied Optics | volume=9 | issue=8 | date=1970-08-01 | issn=0003-6935 | doi=10.1364/AO.9.001883 | page=1883}} They typically use holography to reproduce the optical phase profile of a normal converging lens, albeit on a flat surface.{{cite web |url=http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-28-5-976 |title= Optical performance of holographic kinoforms |accessdate=12 August 2013}}

They can be used in areas such as focusing x-ray radiation, or in the study of nanomaterials. Diamond is often used in kinoform lenses as it has a high thermal conductivity.{{cite web |url= http://phys.org/news168536133.html |title=A Kinoform's Best Friend: Diamond Refractive Lenses for Nanofocusing |accessdate=12 August 2013}} Higher chromatic aberration is a common drawback.