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:
Jul. 23, 2002
Filed:
Sep. 10, 1999
Schott ML GmbH, Jena, DE;
Abstract
The invention relates to a synthetic quartz glass preform which is produced according to the flame hydrolysis technique with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. Said preform has a core area which contains ≧1150 ppm OH, a strain double refraction of ≦5 nm/cm and a resistance to high-energy DUV radiation as a result of a transmission reduction of &Dgr; T ≦0.1 %/cm thickness. The quartz glass has been exposed to the following radiation: wavelength &lgr; =248 nm, laser shot frequency ≧300 Hz, laser shot value ≧10 and rumination ≦10 mJ/cm , and wavelength &lgr; =193 nm, laser shot frequency ≧300 Hz, laser shot value ≧10 and rumination ≦5 mJ/cm . A device for producing said preform comprises a horizontally positioned muffle with two different-sized openings facing each other. The larger of said openings is for removing the preform, the smaller opening being for introducing a burner. The internal chamber of the muffle narrows from the larger opening to the smaller opening.