Presentation Information
[11a-A24-10]Laser micromachining with a large-aperture metalens for 1-µm-band nanosecond lasers
〇Shotaro Kawano1, Kazuya Motohashi2, Mizuho Matoba1, Haruyuki Sakurai1, Kuniaki Konishi1 (1.The Univ. of Tokyo, 2.Koito Manufacturing Co., Ltd.)
Keywords:
Laser micromachining,metalens
Laser micromachining is widely used for fabricating electronic and photonic devices. In most systems, tight focusing is achieved using high-numerical-aperture (NA) objective lenses. However, conventional objectives have bulky housings and short working distances, which limit access to recessed or geometrically complex targets. In this study, we demonstrate laser micromachining using a large-aperture metalens designed for 1064 nm nanosecond laser irradiation. The fabricated metalens combines pillar and diffraction-grating structures and has a 22 mm aperture, an 11.5 mm working distance, and an NA of 0.7. Micro-hole drilling experiments on silicon using 1064-nm nanosecond laser pulses showed machining performance comparable to that of a commercial objective lens. In addition, logo patterning was demonstrated on an image sensor located inside a camera package. These results indicate that large-aperture metalenses are promising focusing elements for laser micromachining because they combine high NA with enhanced spatial accessibility.