[18p-136-1~15] 3.7 Laser processing

△ [18p-136-6] Dot coloring on metal surface by femtosecond-laser double-pulse irradiation

〇Shogo Nishino^1,2, Masaki Hashida^1,2, Masahiro Shimizu³, Yuki Furukawa^1,2, Sadaoki Kojima², Shunsuke Inoue^1,2, Keisuke Takenaka⁴, Masahiro Tsukamoto⁵, Shuji Sakabe^1,2 (1.GSS, Kyoto Univ., 2.ICR, Kyoto Univ., 3.GSE, Kyoto Univ., 4.GSE, Osaka Univ., 5.JWRI, Osaka Univ.)

Keywords:Femtosecond laser, metal coloring

Dot coloring with blue and brown was demonstrated on metal surface irradiated by double-pulse beam consist of two-color femtosecond laser pulses with appropriate time interval. Furthermore, dot coloring with green on titanium was demonstrated for the first time although green has never been achieved before by conventional laser coloring. However we need further investigation to be modified its uniformity. Elemental analysis using Electron Probe Micro Analyzer (EPMA) suggests that the dot coloring was due to the formation of uniform oxidation layer on this area. In the future, we will optimize the laser irradiation conditions for controlling the thickness of oxidation layer and its distribution to be extended dot coloring with other colors including green.