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A new plastic microlens array, consisting of 900 lenslets, has been developed for the Shack Hartmann wave-front sensor. The individual lens is 300 [[micro]meter] x 300 [[micro]meter] and has a focal length of 10 mm, which provides the same focal size, 60 [[micro]meter] in diameter, with a constant peak intensity. One can improve the wave-front measurement accuracy by reducing the spot centroiding error by averaging a few frame memories of an image processor. A deformable mirror for testing the wave-front sensor gives an appropriate defocus and astigmatism, and the laser wave front is measured with a Shack Hartmann wave-front sensor. The measurement accuracy and reproducibility of our wave-front sensor are better than [Lambda]/20 and [Lambda]/i50([Lambda] = 632.8 nm), respectively, in rms. Key words: Plastic microlens array, Shack Hartmann wave-front sensor, deformable mirror.

A novel polarimeter for measuring the two-dimensional (2D) thermal- and mechanical-stress-induced birefringence in solid-state laser materials such as Nd:YAG is proposed. Using this device, we could sensitively measure the direction of the principal birefringence axis as well as the phase shift [Delta] with sign when [Delta] < [Pi]/4. The 2D thermal- and mechanical-stress-induced birefringence in a laser-diode-pumped Nd:YAG rod was successfully measured with the proposed polarimeter. We also found an active quarter-wave Nd:YAG phase retarder.

Efficient lasing of Nd:Ca (Nb, Ga)2-x Ga3-garnet (CNGG) disordered crystal pumped by a laser diode was demonstrated. In the end-pumped cw lasing experiment with a single-stripe diode, a slope efficiency of 24.2% and a maximum optical conversion efficiency of 19.3% were obtained. It was shown that the dependence of cw output power on the pump wavelength is insensitive compared with Nd:YAG because of the broad pump absorption bandwidth of Nd:CNGG. From the diode-bar-pumped experiment, it was confirmed that Nd:CNGG is a promising material for diode-bar pumping to obtain high average power with good beam quality, because of its advantages of a broader pump absorption band compared with that of Nd:YAG and the higher thermal conductivity compared with Nd-doped glasses.

Two types of beam-extraction intense light ion diodes have been investigated. One was a single stage applied-B ion diode that installed on a simple coaxial pulsed power machine Reiden-IV (1 MV, 1 TW, 50 ns). We have measured a beam flux and a beam divergence angle simultaneously with spatial resolution using a newly developed arrayed ion pinhole camera (APC). Measured data show some relation between the distribution of beam divergence and beam flux. This result implies an importance of this type of diagnostics for studying light ion diode. Experiments of another type of diode, a two-stage ion diode, were performed on an induction adder accelerator Reiden-SHVS (2 MV +2 MV, 0.2-TW, 100-ns). In this diode, the output beam of first stage is injected into the second stage diode. The operation of the second diode is controlled by the injected beam. The shadow-box measurements in the two-stage diode indicates an improvement of beam divergence (half width full maximum) from 52 + or - 18 mrad to 27 + or - 6 mrad due to the acceleration at the second diode. This improvement of beam divergence was in agreement with a calculated value using voltages of the first and the second stage diode.

Presents a study which examined the x-ray emission in the water window spectral region from materials irradiated by a slab glass laser. Suitability of carbon as a source material for an x-ray microscopy experiment; Derivation of the electron density and electron temperature of the carbon plasmas; Results of the experiment.

Presents a study that applied an x-ray emission computed tomographic technique in diagnosing the laser implosion uniformity of spherical targets. Background on the effect of the non-uniformity of laser irradiation; Details of the reconstruction of three-dimensional images of compressed core; Results and implications.

Presents a study which investigated the laser-generated plasma x-ray properties in the soft x-ray region. Experimental details; Results and discussion; Conclusions.

Presents a study which examined the properties of shell confinement long-life plasmas produced by a carbon dioxide laser. Use of x-ray spectroscopic methods; Experimental results; Discussion and conclusions.