Power Laser System engineering (PLS)

Summary

Our group’s activities focus primarily on the development of laser drivers for nuclear fusion reactors, and applied research derived from the findings of nuclear fusion developments. Currently, the most promising fusion driver candidate is a solid-state laser excited by a semiconductor laser (LD). So far, the group has developed a high-power glass laser (HALNA, 10 J @ 10 Hz), and a high efficiency YAG laser (LD light → pulse laser light conversion efficiency of 80 %). The group’s research foundations for laser development lies in the investigation of optical materials and film production methods, such as laser materials, mirrors, and non-linear materials. The group addresses the challenges of increasing yield strengths and improving functionality from a variety of different angles, and aims to realize a high energy density laser.

Group website

Research topics

1.Yb : YAG Solid-state Lasers

1.1  Evaluation of New Materials   Kawanaka
1.2 Increasing the Pulse Energy of Cooled Yb : YAG Amplifier   Kawanaka, Sekine
1.3 Increasing the Average Power of Cooled Yb : YAG Amplifier   Tokita, Yoshida
1.4 Characterization of Non-linear Materials   Yasuhara, Takeuchi

2.Nd : YAG Solid-state Laser (enhancing HALNA performance)

2.1 General   Kawashima, Kawanaka
2.2 Improvement of Spatial Beam Shape   Matsumoto, Yasuhara
2.3 Uniform Temperature Distribution of Slab Amplifiers   Kurita
2.4 Stability Control of Longitudinal Modes   Kawashima, Sekine

3.Ultra-high peak power laser

3.1 Improving non-linear material performance and generation of ultra-short pulses   Ogawa

Academic papers and international conference presentations in 2005

• Junji Kawanaka, “Yb-Doped Solid-State Lasers at Low Temperature”, Laser Society of Japan, No. 4 issue, vol. 33, pp. 243-248 (2005).
• S. Tokita, J. Kawanaka, M. Fujita, T. Kawashima, and Y. Izawa, “Sapphire-conductive end-cooling of high power cryogenic Yb:YAG lasers,” Appl. Phys. B vol. 80, pp. 635-638 (2005).
• J. Kawanaka, S. Tokita, H. Nishioka, M. Fujita, K. Yamakawa, K. Ueda and Y. Izawa, “Dramatically Improved Laser Characteristics of Diode-Pumped Yb-Doped Materials at Low Temperature,” Laser Physics 15, pp. 1306-1312 (2005).
• S. Tokita, J. Kawanaka, M. Fujita, T. Kawashima and Y. Izawa, “Efficient High-Average-Power Operation of Q-Switched Cryogenic Yb:YAG Laser Oscillator,” Jpn. J. Appl. Phys 44, L1529-L1531(2005).
• S. Tokita, J. Kawanaka, M Fujita, T. Kawashima and Y. Izawa, “Sapphire-conductive end-cooling of high power cryogenic Yb:YAG lasers,” Advanced Solid-State Photonics (ASSP, OSA), MF44 (2005).
• J. Kawanaka, “New Concept of DPSSL – Tuning laser parameters by controlling temperature -,” 2005 US-Japan Workshop on Laser-IFE (General Atomics, San Diego, March 2005).
• T. Kurita, T. Kawashima, T. Ikegawa, O. Matsumoto, R. Yasuhara, T. Sekine, J. Kawanaka, N. Miyanaga, M. Nakatsuka, Y. Izawa, H. Kan, Y. Tsuchiya, H. Furukawa, T. Kanabe, “Thermally-Edge-Controlled Slab Laser for Inertial Fusion Energy and Applications,” Conference on Lasers and Electro-Optics (CLEO2005, OSA), CMJ5 (2005).
• J. Kawanaka, “A cryo-cooled ytterbium-doped laser materials for IFE driver −New concept of DPSSL-,” 2nd International Workshop on High Energy Class Diode Pumped Solid State Lasers 2005 (HEC-DPSSL 2005), 2-1 (2005).
• T. Kawashima, J. Kawanaka, N. Miyanaga, M. Nakatsuka, Y. Izawa, O. Matsumoto, T. Kurita, R. Yasuhara, T. Ikegawa, T. Sekine, M. Miyamoto, K. Iyama, H. Kan, Y. Tuchiya, and H. Furukawa, “Recent progress of HALNA DPSSL driver development,” 2nd International Workshop on High Energy Class Diode Pumped Solid State Lasers 2005 (HEC-DPSSL 2005), 1-2(2005).
• T. Kawashima, T. Ikegawa, H. Furukawa, R. Yasuhara, J. Kawanaka, and Y. Izawa, “Thermo-optical modeling for the HALNA slab amplifier,” 2nd International Workshop on High Energy Class Diode Pumped Solid State Lasers 2005 (HEC-DPSSL 2005), 3-2 (2005).
• T. Kawashima and T. Kurita, “Design of optical pump delivery system for HALNA,” 2nd International Workshop on High Energy Class Diode Pumped Solid State Lasers 2005 (HEC-DPSSL 2005), 5-2(2005).
• S. Tokita, J. Kawanaka, Y. Izawa, M. Fujita, and T. Kawashima, “Sapphire-cooling at both faces of high-power cryogenic Yb:YAG disk laser,” Conference on Lasers and Electro-Optics Europe 2005 (CLEO/Europe 2005, EPS/IEEE/OSA), CA2-2-MON (2005).
• J. Kawanaka, H. Nishioka, Y. Izawa, and K. Ueda, “Active-mirror oscillator with cryogenically cooled Yb-doped materials” Conference on Lasers and Electro-Optics Europe 2005 (CLEO/Europe 2005, EPS/IEEE/OSA), CA2-3-MON (2005).
• T. Kawashima, T. Kurita, O. Matsumoto, T. Ikegawa, T. Sekine, M. Miyamoto, K. iyama, H. Kan, Y. Tsuchiya, R. Yasuhara, J. Kawanaka, T. Norimatsu, N. Miyanaga, M. Nakatsuka, Y. Izawa, and H. Furukawa, “Diode-pumped, thermally-edge-controlled slab laser with high-energy and large-aperture,” Conference on Lasers and Electro-Optics Europe 2005 (CLEO/Europe 2005, EPS/IEEE/OSA), CA5-1-THU (2005).
• R. Yasuhara, T. Kawashima, T. Ikegawa, O. Matsumoto, T. Kurita, T. Sekine, M. Miyamoto, K. Iyama, Y. Tsuchiya, J. Kawanaka, T. Norimatsu, M. Nakatsuka, Y. Izawa, and H. Furukawa, “Diode-pumped thermally-controlled zig-zag slab laser with 20-J pulse energy in 10 ns at 10-Hz repetition rate,” Pacific Rim Conference on Lases and Electro-Optics 2005 (CLEO-PR, Tokyo, July 2005), Ctul2-3.
• T. Sekine, R. Yasuhara, T. Kawashima, T. Ikegawa, O. Matsumoto, T. Kurita, Y. Tsuchiya, J. Kawanaka, T. Norimatsu, and Y. Izawa, “1-J at 10 Hz output diode-pumped Nd:YLF regenerative ring amplifier,” Pacific Rim Conference on Lases and Electro-Optics 2005 (CLEO-PR, Tokyo, July 2005), Ctul2-4.
• T. Kurita, T. Kawashima, O. Matsumoto, R. Yasuhara, T. Ikegawa, T. Sekine, J. Kawanaka, N. Miyanaga, M. Nakatsuka, T. Norimatsu, Y. Izawa, H. Kan, H. Furukawa, and T. Kanabe, “8.4 J at 10 Hz laser operation of Nd:glass zig-zag slab amplifier pumped by 290 kW peak power diode array,” Pacific Rim Conference on Lases and Electro-Optics 2005 (CLEO-PR, Tokyo, July 2005), Ctul2-5.
• J. Kawanaka, S. Tokita, H. Nishioka, M. Fujita, T. Kawashima, T. Yanagitani, K. Ueda, and Y. Izawa, “Cryogenically-cooled active-mirror oscillator with Yb-doped material for inertial fusion energy driver,” Pacific Rim Conference on Lases and Electro-Optics 2005 (CLEO-PR, Tokyo, July 2005), Ctul2-6.
• O. Matsumoto, T. Kurita, T. Ikegawa, R. Yasuhara, T. Sekine, T. Kawashima, J. Kawanaka, T. Norimatsu, N. Miyanaga, Y. Izawa, M. Nakatsuka, M. Miyamoto, T. Kanzaki, H. Kan, H. Furukawa, and T. Kanabe, “Development of HALNA driver with thermally-edge-controlled slab amplifier module,” 14th International Laser Physics Workshop 2005 (Kyoto, July 2005), Seminor4.4.5.
• T. Kawashima, R. Yasuhara, J. Kawanaka, T. Norimatsu, M. Nakatsuka, Y. Izawa, T. Ikegawa, O. Matsumoto, T. Kurita, T. Sekine, M. Miyamoto, H. Kan, Y. Tuchiya, and H. Furukawa, “Thermal management of high energy diode-pumped solid-state laser for inertial fusion energy and high-field applications,” International Symposium on Topical Problems of Nonlinear Wave Physics 2005 (St.Petersburg-Nizhny Novgorod, Russia, August 2005), NWP-2, pp.55.
• R. Yasuhara, T. Kawashima, H. Furukawa, T. Ikegawa, O. Matsumoto, T. Sekine, T. Kurita, H. Kan, J. Kawanaka, T. Norimatsu, and Y. Izawa, “Face-cooled and edge-insulated multi-disk Faraday rotator for high peak and high power,” International Symposium on Topical Problems of Nonlinear Wave Physics 2005 (St.Petersburg-Nizhny Novgorod, Russia, August 2005), NWP-2, pp.135.
• J. Kawanaka, “Novel High-Power Laser Systemwith Cooled Yb-doped Materials,” Japan Korea Collaborative Workshop on Advanced Technology of Lasers for Laser-aided Fusion Plasma Diagnostics (KAIST, Daejon, Korea, 21 Dec. 2005)
• T. Kawashima, T. Ikegawa, J. Kawanaka, N. Miyanaga, M. Nakatsuka, Y. Izawa, O. Matsumoto, R. Yasuhara, T. Kurita, T. Sekine, M. Miyamoto, H. Kan, H. Furukawa, S. Motokoshi, and T. Kanabe, “The HALNA project: diode-pumped solid-state laser for inertial fusion energy,” Inertial Fusion Sciences and Applications 2005, B. A. Hammel, D. D. Meyerhofer, J. Meyer-ter-Vehn and H. Azechi ed., (Am. Nucl. Soc., 2006) submitted.
• T. Ikegawa, T. Kawashima, H. Furukawa, J. Kawanaka, N. Miyanaga, M. Nakatsuka, Y. Izawa, and H. Kan, “Design of a diode-puped 1-kJ zig-zag slab laser with cryogenically cooled ceramic Yb:YAG,” Inertial Fusion Sciences and Applications 2005, B. A. Hammel, D. D. Meyerhofer, J. Meyer-ter-Vehn and H. Azechi ed., (Am. Nucl. Soc., 2006) submitted.
• N. Miyanaga, M. Nakatsuka, K. Yoshida, H. Nakano, H. Kubomura, T. Kawashima, J. Nishimae, Y. Suzuki, N. Tuchiya, T. Kanabe, T. Jitsuno, H. Fujita, J. Kawanaka, K. Tsubakimoto, Y. Fujimoto, H. Furukawa, J. Lu, S. Matsuoka, T. Ikegawa, Y. Owadano, and K. Ueda, “Conceptual design of laser fusion reactor KOYO-Fast −Laser driver−,” Inertial Fusion Sciences and Applications 2005, B. A. Hammel, D. D. Meyerhofer, J. Meyer-ter-Vehn and H. Azechi ed., (Am. Nucl. Soc., 2006) submitted.
• Junji Kawanaka, Shigeki Tokita, Hajime Nishioka and Ken-ichi Ueda, Masayuki Fujita, Toshiyuki Kawashima, Hideki Yagi and Takagimi Yanagitani, “Efficient Active-Mirror Laser Oscillator with a Cooled Yb:YAG Ceramics,” Advanced Solid-State Photonics (ASSP, OSA), WB8 (2006).
• S. Tokita, J. Kawanaka, Y. Izawa, Masayuki Fujita, and Toshiyuki Kawashima, “High-average-power, high-efficient operation of Q-switched cryogenic Yb:YAG laser,” Advanced Solid-State Photonics (ASSP, OSA), TuB16 (2006).
• O. Matsumoto, R. Yasuhara, T. Kurita, T. Ikegawa, T. Sekine, T. Kawashima, J. Kawanaka, T. Norimatsu, N. Miyanaga, Y. Izawa, M. Nakatsuka, M. Miyamoto, H. Kan, H. Furukawa, and S. Motokoshi, “Development of thermally controlled diode-pumped solid-state laser,” Proc. SPIE, Lasers and Applications in Science and Technology(LASE2006), 6101 (2006) (in press).

Members