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Tanaka, Momoko; Okada, Hajime; Sugiyama, Akira; Nagashima, Keisuke
no journal, ,
We are developing a laser of 1kHz, 1ps, 100mJ as a driver laser to generate THz wave for quantum control studies in JAEA. Using a highly-doped laser material, high efficient excitation and a wide spectral band are realized removed, however, a thermal problem due to CW excitation occurs. In this study, we report a qualitative evaluation of temperature rise of Yb:YAG material excited with 940nm laser.
Ochi, Yoshihiro; Nagashima, Keisuke; Okada, Hajime; Tanaka, Momoko; Kosuge, Atsushi; Mori, Michiaki; Kiriyama, Hiromitsu
no journal, ,
At Kansai Photon Science Institute, Japan Atomic Energy Agency, we are developing a new CPA laser system at a wavelength of 1030 nm using Yb:YAG thin-disk (at room temperature) devices as a driver laser for high intensity THz wave generation. The specifications of the system are 100 mJ in output energy, 1 ps in pulse duration, and 1 kHz repetition rate. The amplifier consists of a regenerative amplifier and a multi-pass amplifier. Recently, we have achieved 10 mJ output energy by the regenerative amplifier with pump power of 150 W (2.4 kW/cm
on the Yb:YAG). Detail configuration and current conditions of the regenerative amplifier will be presented.
Tsubouchi, Masaaki
no journal, ,
We developed new optical pump- THz probe time-resolved spectroscopy to study dynamics of free electron carrier on Si.
Kiriyama, Hiromitsu; Ochi, Yoshihiro; Mori, Michiaki; Tanaka, Momoko; Okada, Hajime; Kosuge, Atsushi; Nagashima, Keisuke
no journal, ,
We report on the development of laser-diode (LD) pumped Yb:YAG chirped-pulse amplification (CPA) laser system. In the presentation, we show the energy extraction, pulse compression, and temporal and spatial qualities. In addition, we introduce the design for high-repetition rate system.
Kasajima, Tatsuya; Yokoyama, Keiichi
no journal, ,
no abstracts in English
Kosuge, Atsushi; Ochi, Yoshihiro; Okada, Hajime; Tanaka, Momoko; Mori, Michiaki; Kiriyama, Hiromitsu; Nagashima, Keisuke
no journal, ,
Femtosecond laser source with high average power are attractive tools for industrial and scientific applications and its research and development are done all over the world. The thin disk laser which has a very thin disk gain medium solves the thermal problems occurring in conventional high power rod and slab lasers. In this presentation, we developed a high average power diode-pumped Yb:YAG thin disk oscillator. The thickness of the thin disk gain medium is 200 micrometers and it is mounted directly onto a heat sink and used in reflection. The heat flow is mainly one dimensional towards the heat sink, which significantly reduces thermal problems. We demonstrated the passively mode locked thin disk Yb:YAG laser using a saturable absorber mirror (SESAM) and a second harmonic nonlinear mirror (NLM) technique with a LBO crystal.
Itakura, Ryuji
no journal, ,
We investigate coherent correlation between dynamical alignment and angle-dependent ionization of NO in intense laser fields in the state-resolved manner. When neutral molecules are partly ionized in intense laser fields, a hole in the rotational wave packet of the remaining neutral NO is formed by the ionization, whose rate depends on the alignment angle of the molecular axis with respect to the laser polarization direction. Rotational state distributions of NO are experimentally observed with the spectroscopic technique and then the characteristic feature that the population at higher J levels is increased by the ionization can be identified. Time-dependent Schrodinger equation is numerically solved by taking into account of the influence of ionization.
Matsuoka, Leo
no journal, ,
no abstracts in English
Yokoyama, Keiichi
no journal, ,
no abstracts in English
Hashimoto, Masashi; Yokoyama, Keiichi
no journal, ,
no abstracts in English