The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 2001
Filed:
Sep. 03, 1999
Applicant:
Inventor:
Masaki Shiozawa, Sagamihara, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 1/100 ;
U.S. Cl.
CPC ...
G02B 1/100 ;
Abstract
An optical member for transmitting light of a wavelength less than about 200 nm including crystalline calcium fluoride with a potassium content less than about 0.5 ppm, wherein a degradation in a transmissivity of the optical member after an irradiation for a fixed period of time with the light of the wavelength of less than about 200 nm is less than about 5% of a transmissivity of the optical member before the irradiation.