| 摘要 |
PURPOSE:To obtain a laser resonator, in which alignment is easy and aligning quantity can be remarkably decreased even if the attaching state of a returning mirror is changed, by constituting the returning mirror so as to have two reflecting surfaces forming a right angle. CONSTITUTION:Laser light repeats reflections between an output mirror 1 and a rear mirror 2 by way of a returning mirror 3b. Thus the laser light is amplified. Part of the light is transmitted through the output mirror 1 and taken out. Even if the returning mirror is deviated in the direction of alpha, incident light 4 and reflecting light 5 can always keep a parallel state. The reflecting light is slightly deviated by the deviation of the direction Y and the direction theta. The deviation is a parallel movement. Since the length of a light path is long, said devaition is minute and negligible in comparison with the deviation of angles. In the resonator using such a returning mirror, deformation in the direction does not affect the alignment of the laser, even if the attaching angle of the returning mirror is changed due to thermal effect and the like. Only the deformation in the direction beta is considered. Therefore, the attaching structure is simple and the change in alignment can be made small. |
