Multifocal Lenses - Diffractive optical elements (DOE)

Diffractive optics gives the possibility to create several output beams from one incident beam. Thus instead of one focus typical for refractive lens it is possible to obtain several focuses, located along the optical axis, each in its focal plane. Such lenses are called multifocal lenses. They are important for parallel zoom systems, optical sensors, ophthalmic applications. They can also be used as quasi elongated focus elements, creating effectively a larger depth of focus in material processing operations