| 摘要 |
PURPOSE:To obtain a laser output of a stable Gaussian beam over a long term by a method wherein a multi-element light detector is provided to detect the beam diameter of a leaking light which leaks from the side of the total reflection mirror of laser resonator mirrors and a processing circuit which processes a signal from the multi- element light detector and an aperture inner diameter control circuit which controls the inner diameter of the aperture in accordance with the signal from the signal processing circuit are provided. CONSTITUTION:A source is connected between the anode 5 and the cathode 7 of a laser tube 1 to produce a discharge and a laser oscillation is induced by a light resonator constituted by an output mirror 3, an aperture 15 and a total reflection mirror 4 to output a laser beam 11. The beam diameter of a leaking light 11' on the side of the total reflection mirror 4 is enlarged by a lens 12 and detected by a multi-element light detector 13. An output signal from the multi-element light detector 13 is processed by a processing circuit 14. The inner diameter of the aperture 15 is controlled by an aperture inner diameter regulating circuit 16 in such a manner that the maximum output is obtained when the laser beam is a Gaussiam beam (TEMoo mode). Therefore, the inner diameter 8 of a mode suppression graphite disc 10 and the inner diameters 8' of the center holes of a group of graphite discs 6 may be identical and the output power of the laser beam 11 need not be sacrificed. |
