Electromagnetic ray beams focusing method for data storage medium, involves generating evanescent wave fields of pre-focused ray beams as input evanescent fields by utilizing non linear medium e.g. two-photon absorber

摘要

The method involves focusing incident electromagnetic ray beams from a source using a lens. Evanescent wave fields of the pre-focused electromagnetic ray beams are generated as input evanescent fields by utilizing a non linear medium such as a two-photon absorber, a semiconductor, a semiconductor quantum wave structure, and a semiconductor quantum dot structure. A nonlinear polarization is produced by the absorber depending on the field strength of the electromagnetic ray beams. An independent claim is also included for an arrangement for focusing electromagnetic ray beams below a diffraction limit.