Abstract
In the textile industry, new technology and high value-added product using laser are expected. We have
developed laser marking fiber and micro-marking on this fiber using YAG laser. But YAG laser is too expensive, so the
laser device with a higher cost performance is demanded. An excellent light source, laser diode (LD) presents several
advantages such as small size, light weight, high efficiency, and low cost. We have developed a violet laser diode(VLD
wave length : 405nm) for direct processing. Because wavelength of VLD is short, VLD is expected to produce a small
beam spot. A precisely focused VLD beam has been used for microscopic color marking of dye to PET material as well
as color marking on fibers. The laser light of a single-mode VLD is collimated, and the wavefront aberration of this
beam is measured and corrected so that the light can be precisely focused. This corrected light is precisely focused and
the dye and pigment applied to plastic surfaces is irradiated. As the result, we were able to achieve color-micro-marking
without using any absorbents on the irradiated portion. The scheme has enabled 100 micron and 200 micron
microscopic character marking, and microscopic marking to polyester fibers has been achieved.
