METHOD FOR FLATTENING SURFACE AND METHOD FOR PRODUCING OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To measure surface roughness in real time while performing near-field light etching. SOLUTION: An optical element 2 located in a raw material gas atmosphere is irradiated with light having a longer wavelength than the absorption-end wavelength of a gas molecule in a raw material gas and then a corner part is etched by dissociating the raw material gas based on near-field light emitted at least on the corner part of unevenness formed on the surface of the optical element 2. A laser beam for measuring surface roughness is irradiated onto the surface of the optical element 2 while etching, the strength of scattered light where the laser beam is scattered on the surface of the optical element 2 is measured and then the surface roughness is measured by etching the corner based on the measured strength of the scattered light. COPYRIGHT: (C)2011,JPO&INPIT