[19a-PA4-1~13] 3.7 Laser processing

[19a-PA4-13] Optical vortex microfabrication of Au thin film

〇(B)Miki Kawamoto¹, Sho Kawagoe², Ryosuke Nakamura³, Daisuke Nakamura², Takashige Omatsu^3,4 (1.Kyushu Univ., 2.Grad. Sch. ISEE, Kyushu Univ., 3.Chiba Univ., 4.MCRC Chiba Univ.)

Keywords:optical vortex, microfabrication, micro structure

Optical vortex has spiral wave front and annular intensity distribution. The optical vortex laser processing has been paid attention recently, and chiral structure fabrication by irradiating optical vortex to metal and semiconductor targets such as Si and Ta have been reported. In this study, we successfully fabricated Au microneedle with a helical structure due to orbital angular momentum by irradiating Au thin film with a single vortex pulse. Furthermore, it was confirmed that the structure of the opposite direction was formed by changing the sign of the orbital angular momentum.