演講/活動

*** Welcome all to come ***
 

Speaker：

Prof. Kuniaki Konishi

The University of Tokyo, Japan
 

Time：Oct. 20, 2023 Friday 10:00—11:00AM

Venue：ED103, 1F Engineering Building 4, NYCU 陽明交大工程四館103室

Host : Prof. Ming-Lun Tseng 曾銘綸/Institute of Electronics, NYCU

Language : English

 

Abstract：

Laser processing using ultrashort pulsed lasers offers numerous advantages over traditional methods. It enables the precise shaping of materials like metals, dielectrics, and composites without causing contact or thermal damage. This technology's control is crucial for industrial applications, but the complex nature of laser-induced material damage in non-equilibrium open systems remains partially understood.

To address these challenges, we've developed a method linking femtosecond laser pulse beam profiles to resulting shapes. This approach enables precise measurement of the beam profile at the laser focus point and establishes an accurate correspondence between intensity at each spot in the laser and crater depth [1]. These results demonstrate high reproducibility and accuracy in dielectric laser processing. Additionally, nonlinear simulations predict crater radius accurately across various beam intensities [2], demonstrating femtosecond laser processing's ability for submicron-scale material precision.

We also applied femtosecond laser processing technology for creating three-dimensional microstructures like the moth-eye, which effectively reduces electromagnetic wave reflection in the terahertz wave range and operates at space observatories [3,4,5].

In this presentation, I will highlight our recent advances in femtosecond laser processing, encompassing both fundamental research and practical applications.

[1] H. Sakurai et al., Communication Materials 2, 38 (2021)

[2] R. Yamada et al., Optics Express 31, 7363 (2023)

[3] H. Sakurai et al., OSA Continuum 2, 2764 (2019)

[4] R. Takaku et al., Journal of Applied Physics 128, 225302 (2020)

[5] R. Takaku et al., Optics Express 29, 41745 (2021)

 

Bio：

Kuniaki Konishi’s short CV

He received his B.S. (2001), M.S. (2003), and Ph.D. (2008) degrees from the Department of Applied Physics, University of Tokyo. From 2003 to 2005, he worked as a researcher at NTT Photonics Laboratories, Nippon Telegraph and Telephone Corporation. From 2008 to 2014, he was a Project Assistant Professor at the Photon Science Center, University of Tokyo. From 2014 to 2021, he worked as an Assistant Professor at the Institute for Photon Science and Technology at the University of Tokyo. Since 2021, he has been an Associate Professor at that institute. His main research interests are metamaterials, laser processing, and terahertz spectroscopy.