| 摘要 |
PURPOSE:To reduce driving force even if a sector disk rotates at high speed by transmitting a first pulse laser beam through a light transmission part of the rotary sector disk on which the light transmission part and the reflection surface are formed radiately, making a second pulse laser beam incident on the reflection surface and composing these on the same axis. CONSTITUTION:The inside of an evacuation vessel 6 is evacuated into a high vacuum and the sector disk 11 is rotated at high speed. When marks 17a and 17b are detected by a detector 21, a driving source 3 is driven by a control signal A and a first pulse gas laser beam oscillator 1 is oscillated and the laser beam L1 is outputted and goes straight on through the light transmission part 13 and a transmission aperture 8. Meanwhile, when marks 18a and 18b are detected, a driving source 4 is driven by a control signal B and a second pulse gas laser beam oscillator 2 is oscillated and the laser beam L2 is outputted and superposed on the same axis on the laser beam L1 via a reflection mirror 10, a transmission aperture 9 and the reflection surface 14 and goes straight on through the transmission aperture 8. The laser beam oscillations are composed and the highly repeated pulse laser beam is obtained. |
