Patent ID: 7514382

Claim:
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/cm 3 and at most 5×10 14 defects/cm 3 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 I 495 at 495 cm −1 and the scattering peak intensity I 606 at 606 cm−1, to the scattering peak intensity I 440 at 440 cm −1 in the laser Raman spectrum, I 495 /I 440 and I 606 /I 440 are at most 0.585 and at most 0.136, respectively.