| 摘要 |
<p>A synthetic quartz glass optical member to be used together with a light having a specific wave length of 250 nm or less which has a difference between the maximum and the minimum values of transmissivity [%/cm] per 1 cm of thickness of such a light in a given direction in a plane perpendicular to the ray axis of the light of 2.0 %/cm or less.</p> |
