␤-decay properties of nuclei are studied in the framework of proton-neutron quasiparticle random-phase approximation with a schematic Gamow-Teller residual interaction. Particle-hole and particle-particle terms of the separable Gamow-Teller force are consistently included for both ␤ ϩ and ␤ Ϫ directions, and their strengths are fixed as smooth functions of mass number A of nuclei in such a way that the calculation reproduces observed ␤-decay properties of nuclei. Using the fixed interaction strengths, ␤-decay half-lives of nuclei up to Aϭ150 are calculated, and generally good agreement with experiment is obtained. A schematic force which is relevant to the unique first-forbidden decay is also included in a similar way to the Gamow-Teller force, and its effects are studied. ͓S0556-2813͑96͒03512-1͔

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Semiconductor optical amplifier (SOA) module, RSOA, SOA with mirror has become an essential component to be at the head of negative feedback amplification effect, optimum gain, and cross-gain modulation with demand for longer transmission lengths. The SOA module is expected to have an advantage of exhibiting much faster negative feedback (NF) response because distance of optical signal passing through component to component is shorten than system connected with fibers. Scattered degree and baseline line difference of eye-pattern diagrams demonstrated that NF effect can be compensated compactness and stability from band pass filter in SOA module. Modulation degree (MD) of input and output signals confirmed that SOA module with NF effect can be stabilized gain and waveguide of output signal and reduced a wave distortion as well as consistent with results in eye-pattern waveform and bit error rate (BER). All-optical switching triode with SOA module was realized in about 60 % output modulation degree at control power range of 0.01 to 1 mW. We propose that our manufactured SOA module become strong component candidate to realize all optical switching triode with NF effect for high speed optical processing in next generation.

From small signal gain measurements for the CO2 regular and sequence band transitions in a waveguide laser medium, the foreign gas effect on the ν3-mode vibrational temperature is investigated and compared with that in a large-bore flow tube, ordinary laser medium. The vibrational temperature in the waveguide is apparently higher than that in a large-bore flow tube, ordinary laser at any partial pressure of foreign gas in the gas mixture. The vibrational temperature decreases with increasing foreign gas N2 partial pressure, whereas it increases with increasing He partial pressure. The total and partial derivatives of the vibrational temperature for the variables of the foreign gas pressure and the injected power are experimentally obtained and discussed.