| 摘要 |
PROBLEM TO BE SOLVED: To improve alignment stability and beam quality stability and to prevent the reduction in laser output due to breakdown. SOLUTION: Incident light is split with a beam splitter 11, made incident on the beam splitter 11 through a path comprising a total reflection mirror 12a, a lens 13, total reflection mirrors 12b and 12c, a lens 13 and a total reflection mirror 12d, combined with incident light and made emitted from the beam splitter 11. A slit 14 is provided on the emission side of the beam splitter 11, just expanded portion of beam profile is intersected by the slit 14 when the beam profile is expanded by the tilt of the total reflection mirrors 12a to 12d due to a thermal deformation or the like. Thus, the same profile as the incident beam can be obtained. It is also possible that a position sensor which detects the position of the incident laser beam is provided and the angle of the total reflection mirrors is so adjusted that the position of the laser beam is located at a predetermined position on the basis of the positional information of the position sensor. COPYRIGHT: (C)2005,JPO&NCIPI |
