| 摘要 |
PURPOSE:To increase distances among lenses and a sample, and to obtain micro- beams by changing laser beams passing through a pin hole into parallel beams by the lens (f1) and diaphragming parallel beams by the lens (f2<f1). CONSTITUTION:The beams of a laser oscillator 2 are condensed 3, passed through a pin hole 12, turned into parallel beams by a lens 5 (a focal length f1), amplified 6, and condensed by a lens 7 (a focal length f2<f1), thus forming micro-beams 10. The diameter of a condensing point 9 d2=d1Xf2/f1 holds when the diameter of the pin hole 12 is represented by d2. An adjusting lens 20 is positioned in front of a visible laser beam source 19, beams projected to the lens 7 through a semitransparent mirror 21 and an optical axis are conformed and projected and beams are made to coincide with the light spot 9, and a position is made clear when the light spot is colored. According to the constitu tion, micro-beams having a diameter of 1mum or less are acquired while increas ing a distance between the lens 7 and a sample 15, and the method is effective for ultrafine processing. |
