US 7,514,382 B2
Synthetic quartz glass for optical member and its production method
Yoshiaki Ikuta, Yokohama (Japan); and Noriyuki Agata, Koriyama (Japan)
Assigned to Asahi Glass Company, Limited, Tokyo (Japan)
Filed on Apr. 06, 2006, as Appl. No. 11/398,669.
Application 11/398669 is a continuation of application No. PCT/JP04/19443, filed on Dec. 17, 2004.
Claims priority of application No. 2003-418814 (JP), filed on Dec. 17, 2003.
Prior Publication US 2006/0183623 A1, Aug. 17, 2006
Int. Cl. C03C 3/06 (2006.01); C03B 20/00 (2006.01)
U.S. Cl. 501—54  [501/53] 5 Claims
 
1. A synthetic quartz glass for an optical member to be used for an optical device employing a light having a wavelength in range of 170 nm to 400 nm as a light source, said synthetic quartz glass comprises (i) substantially no oxygen excess defects no dissolved oxygen molecules, and (ii) oxygen deficient defects within a range of at least 1×10 13 defects/cm3 and at most 5×1014 defects/cm3 least,
wherein a concentration of an OH group is most 100 ppm and a concentration of a chlorine is at most 10 ppm, and
the ratios of the scattering peak intensity I495 at 495 cm −1 and the scattering peak intensity I606 at 606 cm−1, to the scattering peak intensity I440 at 440 cm−1 in the laser Raman spectrum, I495/I440 and I606/I440 are at most 0.585 and at most 0.136, respectively.