US 11,988,807 B2
Optical member, method of producing optical member, and apparatus for transmitting optical information
Soichiro Ahiko, Shinjo (JP); Daisuke Tanaka, Shinjo (JP); and Shinichi Umeda, Yokohama (JP)
Assigned to MITSUI CHEMICALS, INC., Minato-ku (JP); and AHIKO FINETEC, LTD., Shinjo (JP)
Appl. No. 17/425,761
Filed by MITSUI CHEMICALS, INC., Tokyo (JP); and AHIKO FINETEC, LTD., Shinjo (JP)
PCT Filed Feb. 4, 2020, PCT No. PCT/JP2020/004094
§ 371(c)(1), (2) Date Jul. 26, 2021,
PCT Pub. No. WO2020/170801, PCT Pub. Date Aug. 27, 2020.
Claims priority of application No. 2019-026906 (JP), filed on Feb. 18, 2019.
Prior Publication US 2022/0120935 A1, Apr. 21, 2022
Int. Cl. G02B 1/04 (2006.01); B24B 37/08 (2012.01); G02B 6/26 (2006.01); G02B 27/01 (2006.01)
CPC G02B 1/04 (2013.01) [B24B 37/08 (2013.01); G02B 6/262 (2013.01); G02B 2027/0125 (2013.01); G02B 27/0172 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method of producing an optical member comprising an organic polymer, the method comprising:
a step of preparing a molded member including the organic polymer,
a first polishing step of polishing the molded member with a polishing pad, after arranging the molded member in a movement restriction member which restricts the movement of the molded member during the polishing of the molded member, and
a second polishing step of polishing the molded member after being subjected to the first polishing step, with a suede type polishing pad in which a nap layer is provided and a polishing liquid containing an abrasive material made of alumina,
wherein, in the first polishing step, the molded member is polished using an abrasive material having a grain size of 3 μm or more and the optical member is produced from the molded member by the first polishing step and the second polishing step,
wherein the optical member comprises a surface A which has an area of 1 mm2 or more, and in which a flatness of a region having an area of 1 mm2, as measured by a non-contact type optical flatness meter, is 80 μm or less, a plurality of linear marks having a height of 50 nm or less are observed, in an image of a region having an area of 4,200 μm2 in the surface A, when the region is imaged by a non-contact type optical surface roughness tester, and the plurality of the linear marks are polishing marks.