Patent ID: 11940595
Assignee: HOYA LENS THAILAND LTD.
Field: Machine tools (Mechanical engineering)
Classification: CPC G  B  C | IPC C  G

Claim 0:
1. A method for producing an optical member, the method comprising:
removing a portion of a low refractive index layer, which is the outermost layer of a multilayer structure,
wherein the low refractive index layer and a high refractive index layer are layered on each other; and
removing the portion of the low refractive index layer by performing non-heating processing on an antireflection film that is formed to cover an optical surface of an optical base member and has the multilayer structure, through irradiation with an ultrashort pulse laser beam so as to expose the high refractive index layer,
wherein the ultrashort pulse laser beam has a pulse width of less than 100 picoseconds, and
wherein, in the high refractive index layer that is exposed through removal of the low refractive index layer, a ratio t1/t2 between a thickness t1 of a removed portion of the low refractive index layer and a thickness t2 of a non-removed portion of the low refractive index layer is in a range of 0.90 or more and 1.00 or less.