Three-dimensional dielectric microlenses and ridge-type optical waveguides were fabricated by laser-induced thin film depositiontechniques. For this purpose films were produced not only in localized areas on substrates, but also with film thickness profile controlled as suitable for each device. A spherical thickness distribution was obtained in the central part of silicon oxide films deposited by CO₂-laser chemical vapor deposition (CVD), while the shape was improved by post-deposition wet etching. Dielectric optical waveguides were produced also from ridges drawn by laser CVD, where the CO₂ laser and an argon-ion laser were used for quartz and silicon substrates, respectively. Laser-induced vaporization provided a point molecular source, and by placing a mask between a quartz target and a substrate either microlenses or optical waveguides were produced with the thickness profile controlled by residual gas pressure in a cell. Finally, we used an ArF laser to modify etch rates of silicon nitride films locally during plasma deposition and produce optical waveguides.

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An output power of more than 5.5mW at 531nm was obtained from a single-frequency green laser using a microchip NYAB (Nd_xY_1-xAl₃ (Bo₃) ₄) crystal. Microchip laser was constructed a 500 μm cavity length and pumped by a diode laser at 480mW with an optical fiber. The slope efficiency was 1.46% and the stability of output power was less than ± 0.2%.

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A time evolution in the electric resistance of a glow-discharge causes a difficulty in designing of a power source electric circuit for exciting short pulse lasers. In the present paper we prop-ose a new glow-discharge model to calculate a transient value of the glow-discharge resistance for the electric circuit analysis. The model deals with a temporary behavior of the discharge re-sistance that depends on both discharge current and discharge resistance itself. Discharge vol-tages and currents calculated agree fairly well with those measured in a fast-axial-flow pulse CO₂ laser, a TEA-CO₂ laser, an excimer laser and a copper vapor laser.

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Imaging plates that contain a photostimulable phosphor material of BaFBr: Eu²⁺ are found to be useful for recording beam profiles of ultraviolet and vacuum ultraviolet pulsed lasers. We de-sign and construct a profilemeter which can record, read, and erase images in vacuum. By using the system beam patterns of the Ar₂ excimer laser are reconstructed for both with and without the laser resonator. The argon gas pressure denendence of images is also studied.

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Infrared diode laser absorption spectroscopy (IRLAS) was used to measure the CH₃ (methyl) radical density in an RF-discharge methane plasma. It was found that the CH₃ radical density was of the order of 10¹² cm^-3. We also measured the CH₃ radical density as a function of Xe or Ar gas partial pressure, and this partial pressure dependence shows that the addition of Xe brings about an increase in the CH₃ radical density.

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Cavity conditions of Ti: sapphire lasers pumped by a pulsed laser were investigated from a standpoint of the extention of the tuning range. Analytical calculation predicts that the tuning range increases with increasing pump light fluence into the Ti: sapphire crystal, and with de-creasing cavity loss. Therefore, the extention of the tuning range is obtained by increasing the reflectivity of output mirror and by using a low-loss prism tuner instead of a glazing incidence grating. Increasing the pump light fluence is effective, but that is limited by the damage threshold of the crystal. Practically, the wavelength dependance of the cavity mirrors also nar-rows the tuning range. Experimentally, a tunable operation over 700nm to 925 nm is achieved with a prism tuner and a pair of broad-band mirrors at a moderate pump light fluence less than 2J/cm².

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