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:
Oct. 07, 2014
Filed:
Jun. 29, 2013
Gigaphoton Inc., Tokyo, JP;
Shinji Nagai, Hiratsuka, JP;
Fumika Yoshida, Hiratsuka, JP;
Osamu Wakabayashi, Hiratsuka, JP;
Kouji Kakizaki, Hiratsuka, JP;
Gigaphoton Inc., Tokyo, JP;
Abstract
A gas discharge chamber that uses a calcium fluoride crystal which reduces a breakage due to mechanical stress (window holder and laser gas pressure), thermal stress from light absorption, and the like, increases the degree of linear polarization of output laser, and suppresses degradation due to strong ultraviolet (ArF, in particular) laser light irradiation. A first window () and a second window () of the gas discharge chamber have an incident plane and an emitting plane in parallel with a (111) crystal plane of their calcium fluoride crystal. With respect to an arrangement where laser light entering the calcium fluoride crystal passes through a plane including a <111> axis and a <001> axis of each of the first window () and the second window () as seen from inside the chamber (), the first window () and the second window () are arranged in positions rotated in the same direction by the same angle about their <111> axis.