BEAM IRRADIATION APPARATUS, OPTICAL APPARATUS HAVING BEAM IRRADIATION APPARATUS FOR INFORMATION RECORDING MEDIUM, METHOD FOR MANUFACTURING ORIGINAL DISK FOR INFORMATION RECORDING MEDIUM, AND METHOD FOR MANUFACTURING INFORMATION RECORDING MEDIUM

摘要

A beam irradiation apparatus includes a beam generation source (41) for generating at least either of an optical beam, an electron beam and an ion beam, and a focusing lens (48) for focusing a beam emitted from the beam generation source (41). The beam irradiation apparatus includes at least first and second focus control mechanisms (71) and (72) each controlling a focus position of the beam with respect to the same lens system forming the focusing lens, so as to focus the beam onto an irradiation object (40) by using the focusing lens (48), whereby it possible to obtain a minute beam spot and to conduct a reliable, and stable focus control.