2004 Volume 47 Issue 3 Pages 497-500
Laser microfabrication using a diffraction-free beam (Bessel beam) was performed. Microfabrication with a deep focal depth is possible because a diffraction-free beam has a main lobe with a small diameter, which does not depend on propagation length. The diffraction-free beam was generated using an axicon lens, and the generation was confirmed using an optical microscopy image of a laser-fabricated spot on a silicon wafer. Nevertheless using a nanosecond pulsed Nd:YAG laser, microfabrication with a spot diameter < 1µm was realized. As a result of the deep focal depth of the diffraction-free beam, even if we change the work distance within a range of several millimeters, we are still able to maintain the diameter of the laser- fabricated spots to approximately 1µm. Since an almost straight penetration hole with a diameter of 3µm was drilled into SUS304 foil (20µm thick), it was found that the diffraction-free beam has a high feasibility for the high-aspect-ratio laser drilling of an opaque material due to its deep focal depth.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering