[5presentations] Photonics West 2024

Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XXVIII および Laser-based Micro- and Nanoprocessing (LBMP) XVIII in SPIE. Photonics West 2024（サンフランシスコ、アメリカ）にて、宮地研が関わる研究成果を5件発表いたしました。

LAMOM

[12872-20] Oral presentation

Fabrication of 3D CYTOP biochip using two-photon polymerized mold towards super-resolution bioimaging

Author(s): Mirai Hanzawa, Tokyo Univ. of Agriculture and Technology (Japan), RIKEN Ctr. for Advanced Photonics (Japan); Kotaro Obata, RIKEN Ctr. for Advanced Photonics (Japan); Felix Sima, CETAL, Institutul National pentru Fizica Laserilor, Plasmei si Radiatiei (Romania), RIKEN Ctr. for Advanced Photonics (Japan); Hiroyuki Kawano, RIKEN Ctr. for Brain Science (Japan), RIKEN Ctr. for Advanced Photonics (Japan); Kazunari Ozasa, RIKEN Ctr. for Advanced Photonics (Japan); Yasutaka Hanada, Hirosaki Univ. (Japan); Godai Miyaji, Tokyo Univ. of Agriculture and Technology (Japan); Atsushi Miyawaki, RIKEN Ctr. for Brain Science (Japan), RIKEN Ctr. for Advanced Photonics (Japan); Koji Sugioka, RIKEN Ctr. for Advanced Photonics (Japan)

30 January 2024 • 2:35 PM - 2:55 PM PST | Moscone Center, Room 215 (Level 2 South)

As a platform for high resolution bioimaging, biochips with a refractive index very close to that of a culture medium (water) are highly demanded. CYTOP (AGC Corporation) is a promising material, since its refractive index (1.34) is almost similar to that of water (1.33). However, high transparency in also the ultraviolet region and high chemical resistance of CYTOP make it difficult to fabricate 3D microstructures for biochips. In this study we present fabrication method of 3D biochips based on CYTOP for cell observation by the molding process using 3D micro/nanostructures fabricated by two-photon polymerization with femtosecond laser.

[12872-35] Poster Presentation

Enhancement of transmitted light from femtosecond-laser-induced periodic nanostructure on glass

Author(s): Takemichi Miyoshi, Tokyo Univ. of Agriculture and Technology (Japan), National Institute of Advanced Industrial Science and Technology (Japan); Hideyuki Takada, Dai Yoshitomi, Aiko Narazaki, National Institute of Advanced Industrial Science and Technology (Japan); Godai Miyaji, Tokyo Univ. of Agriculture and Technology (Japan)

30 January 2024 • 6:00 PM - 8:00 PM PST | Moscone Center, Room 2003 (Level 2 West)

To identify the formation of periodic nanostructures induced by superimposed multiple shots of femtosecond laser pulses on transparent materials, we developed a novel in-process monitoring technique by observing the reflectivity and the transmittance of the surface. The transmittance at the glass surface having the line-like periodic nanostructures with a period of ~200 nm and a depth of ~1 μm achieved 200% in the center of the ablation trace. By simulating the time-dependent electromagnetic-field distribution of the illumination light passing through the nanostructured surface, the high transmittance can be attributed to anti-reflection and lens effects induced by a low refractive index with the nanostructured surface.

LBMP

[12873-12] Oral presentation

Formation and characterization of 2D-LIPSS on Ti surfaces with GHz burst mode femtosecond laser pulses

Author(s): Shota Kawabata, Tokyo Univ. of Agriculture and Technology (Japan), RIKEN Ctr. for Advanced Photonics (Japan); Felix Sima, Institutul National pentru Fizica Laserilor, Plasmei si Radiatiei (Romania), RIKEN Ctr. for Advanced Photonics (Japan); Shi Bai, Kazunari Ozasa, Kotaro Obata, RIKEN Ctr. for Advanced Photonics (Japan); Godai Miyaji, Tokyo Univ. of Agriculture and Technology (Japan); Koji Sugioka, RIKEN Ctr. for Advanced Photonics (Japan)

30 January 2024 • 11:10 AM - 11:30 AM PST | Moscone Center, Room 214 (Level 2 South)

The GHz burst mode femtosecond (fs) laser pulses have attracted considerable attention because they can perform better quality and higher efficiency ablation compared to the conventional irradiation scheme of fs pulses (single-pulse mode). Recently, we have demonstrated that the GHz burst mode fs laser pulses can create two-dimensional (2D) periodic surface structures (LIPSS) on Si surfaces. In this paper, we extend the GHz burst mode fs laser processing to form LIPSS on Ti plates. Our aim was to further investigate the more detailed mechanism and explore practical applications. Although the material characteristics of Ti are significantly different from Si, the GHz burst mode fs laser pulses can also create 2D-LIPSS. Then, mesenchymal stem cells cultured on the formed 2D-LIPSS were found to exhibit different behavior on 1D-LIPSS as compared with bare Ti surfaces.

[12873-80] Poster presentation

Formation of homogeneous LIPSS on ZnO by two-beam interference of femtosecond laser pulses

Author(s): Junji Morimoto, Tokyo Univ. of Agriculture and Technology (Japan), RIKEN Ctr. for Advanced Photonics (Japan); Shi Bai, Kotaro Obata, RIKEN Ctr. for Advanced Photonics (Japan); Godai Miyaji, Tokyo Univ. of Agriculture and Technology (Japan); Koji Sugioka, RIKEN Ctr. for Advanced Photonics (Japan)

30 January 2024 • 6:00 PM - 8:00 PM PST | Moscone Center, Room 2003 (Level 2 West)

Irradiation of femtosecond laser pulses at laser fluence near ablation threshold triggers formation of laser-induced periodic surface structures (LIPSS). The formed LIPSS is, however, usually spatially inhomogeneous. Homogeneous LIPSS are preferred for many applications. We have reported that a single nanogroove can be formed by precisely controlling the laser fluence. Based on this result, single nano grooves were able to be formed at the centers of some fringes formed by two-beam interference of femtosecond laser pulses. The formed single nanogrooves acted as a seed to create homogeneous LIPSS in a large area by scanning the laser beams.

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXIV

[12875-25] Invited talk

Data-driven ultrashort pulse laser processing using deep neural network for shape prediction and in-process monitoring (Invited Paper)

Authors: Dai Yoshitomi, National Institute of Advanced Industrial Science and Technology (Japan), Hideyuki Takada, National Institute of Advanced Industrial Science and Technology (Japan), Takemichi Miyoshi, Tokyo Univ. of Agriculture and Technology (Japan), National Institute of Advanced Industrial Science and Technology (Japan), Daisuke Nagai, Tokyo Univ. of Agriculture and Technology (Japan), National Institute of Advanced Industrial Science and Technology (Japan), Godai Miyaji, Tokyo Univ. of Agriculture and Technology (Japan), Aiko Narazaki, National Institute of Advanced Industrial Science and Technology (Japan)

29 January 2024 • 10:30 AM - 11:00 AM PST | Moscone Center, Room 52 (Lower Mezzanine South)

We report on recent research on the development of data-driven ultrashort pulse laser processing to achieve higher productivity and quality. We are developing in-process monitoring, artificial intelligence (AI) optimization, and fast active control of the laser based on them. These key technologies are introduced for micro-drilling of metals and transparent materials and laser-induced periodic surface structure (LIPSS) formation on a silica glass. We demonstrate a fast pulse-to-pulse modulation of the fluences to control the ablation efficiency. A deep neural network was utilized to predict the 3-dimensional shapes of the ablation craters depending on the laser parameters (fluence and pulse duration). The scheme was extended to 10 sequential modulations of fluences. An in-process monitoring of the crack formation on glasses was implemented by optical transmission imaging with deep neural network. The optical reflection/transmission technique was also employed to probe the quality of the LIPSS formation on a silica glass.