| 摘要 |
<p>An optical member made of fluoride crystals, wherein the angle between the <111> axis of the fluoride crystals and the optical axis is 10 to 36° and the member has an optical-axis-direction strain of 2.0 nm/cm or less. The optical member is effective in improving the yield and the accuracy of processing in optical-member production steps. It can attain sufficiently high optical properties.</p> |
