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A compact-sized MCPG with a single discharge stage is developed so as to simulate transient heat loads such as type I ELMs in ITER. The MCPG produces H 2 plasma with the electron density of 1-4×1021 m−3, the ion energy of 15 eV and the pulse width of 0.5 ms. It is found that the absorbed energy density measured by a calorimeter reaches 0.9 MJ/m2 which is comparable to transient heat load of type I ELMs expected in ITER. Erosion of tungsten due to the plasma irradiation produced by the MCPG was confirmed only at the edge parts of the specimen.

Wavefront correction until Zernike polynomial of degree three by a phase conjugate plate has been demonstrated in a high-energy Nd:YLF amplifier system. 108 amplification of 380 mj has been achieved with a near-diffraction-limited beam quality.

In this paper, high-average-power laser media must be operated under strict heating conditions during excitation, laser medium based on silica glass (Nd-doped silica glass:NdSG) is one of the candidate, because it has many favorable thermo-mechanical characters. The mechanical toughness of a laser medium can be evaluated by the thermal shock parameter R/sub T/. It is considered that NdSG can work as a high-average power laser medium, such as an optical booster amplifier for Nd:YAG. Furthermore, since a high-power Nd:YAG laser with an NdSG booster amplifier can also be adapted for excitation of a Ti:Al/sub 2/O/sub 3/ amplifier or an optical parametric chirped-pulse amplification system, it is expected that the realization of a 10-Hz, PW-class table-top laser system will be possible in the future. As the bandwidth of NdSG is wide enough to oscillate and amplify ultra-short pulses, high-average-power laser systems with ultra-short pulses may be also realized.

Phase conjugation mirror with stimulated Brillouin scattering (SBS-PCM) is useful to compensate the wave-front distortion due to the thermally induced aberration and depolarization of average power solid-state lasers. SBS-PCM is reviewed as a promising approach for achieving power scaling of solid-state laser.

A liquid-cooled ceramic Nd:YAG split-disk amplifier have been designed and demonstrated of 3.7-cm clear aperture with the compensation of wavefront degradation due to cooling and the small-signal gain was measured.

This paper proposes a learning scheme for pulse coupled oscillators using the simultaneous perturbation optimization method. Moreover, hardware implementation of the pulse coupled oscillator with learning capability using field programmable gate array is described. It is complicated for ordinary method to find proper parameter values in the pulse coupled oscillator for a proper period, since the pulse coupled oscillator is a kind of recurrent network. The simultaneous perturbation optimization method can give a simple solution to this problem. In addition, this scheme is suitable for hardware realization. Some simulation results of the learning method for pulse coupled oscillators are shown. At the same time, we fabricated FPGA pulse coupled oscillator system with learning mechanism. Results by the hardware system are also shown.

We discovered a new broad fluorescence at 1.25 pm (FWHM: 300 nm) from a bismuth-doped silica glass with 0.8 pm excitation. This luminescent material is promising for a core-fiber material of optical amplifier.

This paper proposes a learning scheme for pulse coupled oscillators using the simultaneous perturbation optimization method. It is complicated for ordinary method to find proper parameter values in the pulse coupled oscillator for a proper period, since the pulse coupled oscillator is a kind of recurrent network. The simultaneous perturbation optimization method can give a simple solution to this problem. The details of the learning scheme are described. Some results of the learning method for pulse coupled oscillators are shown.

Summary form only given. There are several reports of visible luminescence from bismuth-doped glasses and crystals. The spectra of these crystalline and glassy materials were very wide, and the absorption and the fluorescence peaks exist around 240 nm and 380 nm, respectively, however, these emissions from Bi/sup 3+/ are no use for optical communication. We found a new infrared emission at 1.25 /spl mu/m from the bismuth doped silica glass. We report a new infrared fluorescence of bismuth-doped silica glass.

Summary form only given. Diode-pumped solid-state laser (DPSSL) is one of promising candidates as reactor driver for IFE. We have been developing a 10-J output class of diode-pumped water-cooled Nd:glass zig-zag slab laser amplifier module as a smallest-scale test-version of our conceptually designed 4-MJ DPSSL driver. We will show the experimental confirmation of our conceptual design through the investigation of 10-J/spl times/10-Hz module on the key issues such as small signal gain, energy extraction, stored energy, pumping efficiency, thermal effects, beam quality and heat flow in the system.