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A novel monolithic waveguide laser is proposed in which Q-switch operation is possible by the electro-optic effect with poled-polymer films as the waveguide. The characteristics are numerically obtained. Since Nd3+:YLF crystal with an index of refraction lower than those of other laser crystals is used, it is possible to use a polymer film as the waveguide. Due to the long fluorescent life of Nd3+:YLF, an effective Q-switch operation is possible. In this paper, the optimum waveguide parameters are determined by numerical simulation and the gain and the operating voltage of the electro-optic modulation are computed. The effect of the guided wave loss is taken into account. It is found that laser oscillation is possible with excitation of only several milliwatts even under a relatively large loss of 1 dB/cm. Also, by using the directional coupler configuration using the process capability of the polymer film as the Q-switch electro-optic modulator, a giant pulse with a peak power of 0.46 kW can be obtained with an excitation optical input of 100mW and an operating voltage of 38.5 V. © 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(2): 9–18, 1998 [ABSTRACT FROM AUTHOR]

This paper describes experimental analysis of atmospheric channel model of Geostationary Earth Orbit (GEO) satellite-to-ground optical link by utilizing the Laser Utilizing Communication Systems (LUCAS) onboard the optical data relay GEO satellite. Our research work examines the effect of misalignment fading and various atmospheric turbulence conditions. These analytical results clarify that atmospheric channel model is well fitted to theoretical distributions with misalignment fading under various turbulence regimes. We also evaluate several atmospheric channel characteristics, including coherence time, power spectral density and probability of fade, in various turbulence conditions.