RESEARCH
Laser-Matter Interaction Science
We study the interaction between ultra-intense lasers and materials.
We develop novel ultrahigh-intensity lasers, trying to find new physics in light-matter science.
Research Topics
Ultrahigh-intensity mid-infrared lasers
We are developing mid-infrared ultrafast pulse laser at a wavelength of 3 to 5 microns. Our purpose is to generate terawatt-class mid-infrared pulses using solid-state and fiber lasers and optical parametric amplification.
Reference
H. Furuse, D. Ueno, K. Omata, M. Imai, S. Tokita, "Mid-infrared fine-grained Er:Y2O3 laser ceramics fabricated by spark plasma sintering," Ceram. Int. 50, 46925 (2024).
E. Li, H. Uehara, S. Tokita, M. Zhao, R. Yasuhara, "High-power, single-frequency mid-infrared laser based on a hybrid Fe:ZnSe amplifier," Infrared Physics & Technology 136, 105071 (2024).
E. Li, H. Uehara, S. Tokita, W. Yao, R. Yasuhara, "A hybrid quantum cascade laser/Fe:ZnSe amplifier system for power scaling of CW lasers at 4.0–4.6 µm," Optics & Laser Technology 157, 108783 (2023).
Relativistic laser-plasma interaction
Recently we are focusing coherent X-ray generation using the relativistic interaction between ultra-intense lasers and solid surfaces.
Reference
S. Tokita, S. Sakabe, T. Nagashima, M. Hashida, and S. Inoue, “Strong sub-terahertz surface waves generated on a metal wire by high-intensity laser pulses,” Sci. Rep. 5, 8268 (2015).
S. Tokita, K. Otani, T. Nishoji, S. Inoue, M. Hashida, and S. Sakabe, “Collimated fast electron emission from long wires irradiated by intense femtosecond laser pulses,” Phys. Rev. Lett. 106, 255001 (2011).
Laser isotope separation for double beta decay experiment
We try to observe neutrinoless double beta decay in 48Ca, collaborating with Osaka University and University of Fukui. The enrichment of 48Ca isotopes using a high-power laser is expected to improve the sensitivity dramatically.
We are developing an atomic-vapor laser isotope separation technique. Our role is the development of a high-power laser with a narrow linewidth at a wavelength of 423 nm to enrich 48Ca isotopes.
Reference
I Ogawa, T Hiraiwa, J Nakajima, R Yuhaku, M Tozawa, H Niki, S Tokita, N Miyanaga, M Uemukai, A Rittirong, S Umehara, K Matsuoka, S Yoshida, "Laser isotope separation to study for the neutrino-less double beta decay of 48Ca," J. Phys.: Conf. Ser. 2586, 012136 (2023).
I. Ogawa, Y. Kawashima, T. Hiraiwa, M. Tozawa, H. Niki, S. Tokita, B. Han, H. Okuda, N. Miyanaga, S. Umehara, “Development of the laser isotope separation method to study for the neutrino-less double beta decay of 48Ca,” J. Phys.: Conf. Ser. 2147, 012012 (2022).
The search for dark matter
We try to search for unknown particles such as axions using intense lasers, collaborating with Hiroshima University and other institutions. We try to discover low-mass particles using photons by a novel method called
in-vacuum four-wave mixing.
Reference
K. Homma, O. Tesileanu, Y. Nakamiya, Y. Kirita, C. Chiochiu, M. Cuciuc, G. Giubega, T. Hasada, M. Hashida, F. Ishibashi, T. Kanai, A. Kodama, S. Masuno, T. Miyamaru, L. Neagu, V. R. M. Rodrigues, M. M. Rosu, S. Sakabe, J. Tamlyn, S. V. Tazlauanu, S. Tokita, "Challenge of search for cosmological dark components with high-intensity lasers and beyond," Eur. Phys. J. A 59, 109 (2023).
F. Ishibashi, T. Hasada, K. Homma, Y. Kirita, T. Kanai, S. Masuno, S. Tokita, M. Hashida, "Pilot Search for Axion-Like Particles by a Three-Beam Stimulated Resonant Photon Collider with Short Pulse Lasers," Universe 9, 123 (2023).
Femtosecond lasers for Industrial applications
In collaboration with private companies, we are developing compact, high-power femtosecond lasers for microfabrication.
Reference
T. Kanai, G. Okada, and S. Tokita, "Temperature-driven, Symmetry-broken Nonlinear Polarization Evolution Method for Environmentally-stable, Sub-100-fs Mode-locked Fiber Oscillators," in CLEO 2023, Technical Digest Series (Optica Publishing Group, 2023), paper SM1F.2.
