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. 26, 2005
Filed:
May. 30, 2002
Frank Coriand, Jena, DE;
Andreas Menzel, Jena, DE;
Andreas Voitsch, Jena, DE;
Schott ML GmbH, Jena, DE;
Abstract
A synthetic quartz glass preform is produced by flame hydrolysis with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. The 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 ΔT ≦0.1%/cm thickness. The quartz glass has been exposed to the following radiation: wavelength λ=248 nm, laser shot frequency ≧300 Hz, laser shot value ≧10and lumination ≦10 mJ/cm, and wavelength λ=193 nm, laser shot frequency ≧300 Hz, laser shot value ≧10and lumination <5 mJ/cm. Apparatus for producing the preform comprises a horizontally positioned muffle with two different sized openings facing each other. The larger of the 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.