| 摘要 |
PURPOSE:To convert an elliptic beam into a circular beam by arranging a lens system at some angle to the optical axis of the elliptic laser beam. CONSTITUTION:The optical axis 7 of a laser light source 1 arranged at the focal point of a lens 5 on the center axis 6 of the lens has an angle alpha to the center axis 6. In this case, alpha=cos<-1>b/a, where (a) is the long axis of an elliptic laser beam emitted from the laser light source and (b) is the short axis. Consequently, the laser beam having ellipticity b/a as the emitted light 2 from the laser light source 1 is converted by the principal point surface 8 of the lens 5 into a circular beam, which is caused through the 2nd lens 9 to illuminate the coupling end surface 11 of the circular core of an optical fiber 10. When the ellipticity is large, the elliptic beam is converted into a circular beam finally through plural lenses. |
