Recent developments in high power, high energy quasi-cw laser diode arrays offer system designers new opportunities for pumping solid state lasers. It is important to consider the thermal characteristics for system design. We discuss various configurations of heat removal system to understand critical parameters and to optimize system designs under various trade-offs.

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Among various types of lasers, diode lasers are the most compact and easy to control. We present a demonstration of active mode-locking of a commercially available conventional diode laser, and review some high time-resolution spectroscopy in condensed matter using diode lasers.

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Very recent developments in the technology for pumping of solid-state lasers now point to a revolution in the design and application of these devices. This achievement has been brought about by the development of powerful laser diode arrays to serve as pumps for neodymium and other rare earth ions in solid-state hosts. The major benefit of diode pumping as compared to flashlamp pumped system is increased lifetime and higher efficiency. The current state-of-the-art of the design and development of high power side-pumped rod lasers is reviewed. Diode array pump sources, as well as pumping configurations and system architecture of a multi-stage Nd: YAG laser will be described. As an example, a multi-stage laser will be discussed which produced 1.25 Joules per pulse in the free lasing mode at a repetition rate of 40 Hz, 0.75J in a 17 nsec Q-switched pulse, and 0.5J per pulse at the frequency doubled wavelength of 532 nm.

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Josephson junctions of high-T_c Y-Ba-Cu-O films have been successfully fabricated by ablating the films with a pulsed excimer laser. No degradation of the resistance-vs. -temperature characteristics of the films due to the laser ablation was found. The effect of radio frequency irradiation was investigaed at 77K. Clear Shapiro steps were observed under the microwave (8GHz) and millimeter-wave (94GHz) irradiation.

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We attempted to formulate the estimation error of lidar inversion solutions (Klett and Fernald approaches) in terms of optical thickness to establish a unified error formula for the two solutions and to compare the solutions obtained by the different approaches. On the basis of the unified error formula, it is found that the error expression of the lidar inversion solution can be simplified by a “modified optical thickness” and that, in the case of overestimation of the boundary value, the error decreases more rapidly than in the case of underestimation. From the unified error formula and a numerical simulation, it can be concluded that, except for a certain case where the parameter k₂ in the Klett approach is small, the estimation error by the Fernald approach is smaller than that by the Klett approach.

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The absorption profile of the Si 288.2 nm line (3p^{2 1}D2-3p4s ¹P₁) in a cw-RF SiH₄ (10%) /Ar plasma generated in a plasma CVD chamber was determined by absorption spectroscopy using a ring dye laser. The Si atom density at the 3p^{2 1}D₂ level and the Si translational temperature were measured as functions of input power and total pressure in the cw-RF SiH₄ (10%) /Ar plasma.

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