astigmatic light beam

• 象散

astigmatic light beam的用法和样例：

例句

1. Under astigmatism even narrow parallel light beams will not combine into one point.
   有象散存在时甚至很窄的平行光束都不能会聚在一点。
2. The present invention provides an optical pickup apparatus capable of preventing astigmatic aberration.
   本发明提供一种能够防止象散差的光拾取器装置。