Optical head with a diffractive lens

摘要

A head slider (100) for flying above a rotating magneto-optic or optical disk (106) and an optical mechanical assembly (101) with a fixed height above a rotating magneto-optic or optical disk contains magnetic coils and a lens plate (102) with a diffractive optic structure (114) for focusing laser light into a small spot on the disk. The diffractive optic structure (114) may be a zone plate, a phase zone plate or a blazed phase zone plate or other diffractive focusing optical element. The diffractive optic structure (114) does not require curved transparent material such as glass or a high index of refraction. The diffractive optic structure (114) is easily manufactured using lithographic or other techniques.