| 摘要 |
PURPOSE:To oscillate a Gaussian beam with a stabilized output and in TEM00 mode efficiently for a long time by providing a means for controlling the internal diameter of an aperture which operates the aperture according to output signals from a device for measuring laser characteristics. CONSTITUTION:Rotation of a rotation plate 22 causes a pinhole 21 to cross cyclically the lateral cross-section of the reference beam 26 leaked from a total reflection mirror 3, and a beam detector 23 located behind the pinhole 21. The intensity of the reference beam 26 passed through the pinhole 21 is detected by the beam detector 23 and the beam profile is monitored by a signal processor 24. The internal diameter of an aperture 20 is controlled by an aperture internal diameter control circuit 25 so as to maximize the central part output of the reference beam 26. This feed-back control is effected repeatedly to keep the best condition of a diameter of the medium through which the beam passes, thereby obtaining Gaussian beam with stable output. |
