We are studying advanced laser technologies and their applications. Both ultimate technologies of ultrashort pulse generations and ultra narrow-band laser generations were mixed, the optical frequency comb then was born ten years ago. It opened up a new research area such as carrier-envelope-phase dependent phenomena, attosecond physics, and precision spectroscopy by using a femtosecond light source. It also realized the high-repetition and high-intensity physics. It could create wide field of applications in the physics, metrology, medical science, and astronomy. We are developing an Yb-fiber laser-base optical frequency comb, XUV frequency comb, and high-power fiber chirped pulse amplifier system for these applications. The higher repetition rate of >4GHz laser oscillator is also studied.
Optical frequency comb based on an Yb-fiber laser
Xe plasma generated by multi-MHz laser system.
Development and precise control of ultrashort pulse laser system
Generation of soft x-ray and water window harmonics using a few-cycle, phase-locked, optical parametric chirped-pulse amplifier: N. Ishii, S. Adachi, Y. Nomura, A. Kosuge, Y. Kobayashi, T. Kanai, J. Itatani and S. Watanabe, Opt. Lett.37 (2012) 97.
†Vacuum ultraviolet frequency combs generated by a femtosecond enhancement cavity in the visible: B. Bernhardt, A. Ozawa, A. Vernaleken, I. Pupeza, J. Kaster, Y. Kobayashi, R. Holzwarth, E. Fill, F. Krausz, T. W. Hänsch and T. Udem, Opt. Lett.37 (2012) 503-505.
Injection locking of Yb-fiber based optical frequency comb: N. Kuse, A. Ozawa, Y. Nomura, I. Ito and Y. Kobayashi, Optics Express20 (2012) 10509-10518.