5 GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical FDM transmission systems

A 5GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. It is constructed with high-silica channel waveguides and thin-film heaters loaded on the waveguides for frequency tuning     

Wavelength conversion for FM light using light injection induced frequency shift in DFB-LD

A novel wavelength conversion is described. Wavelength conversion of frequency-modulated (FM) light is achieved by combining the lasing frequency shift induced by external light in a DFB-LD and the FM-IM conversion function of a Mach-Zehnder optical filter. In the experiment, 1534 nm FM light is converted to 1550 nm light.<>     

Studies of the crystallisation of gallium hydroxide precipitated from hydrochloric acid solutions by various alkalis

Gallium hydroxide precipitated from aqueous gallium chloride solution on addition of alkalis at varying pH have been aged in the mother liquors for different periods of time. The resulting precipitates have been examined by X-ray diffraction and i.r. spectrophotometry. It is found that the precipitate, separated immediately from the mother liquor after preparation, exists in an amorphous type and transforms to α-gallium oxyhydroxide during aging independent of pH.     

Vascular bundle shape in cross-section and relaxation properties of Moso bamboo (Phyllostachys pubescens)

The variation in the longitudinal and radial direction of the R/T ratio which is the ratio of the radially maximum length (R) to the tangentially maximum width (T) of a vascular bundle and area ratio of vascular bundles, which are cross-sectional image features of bamboo, and the relationships between the R/T ratio or area ratio and relaxation behavior were investigated. These image features varied characteristically in the longitudinal and radial directions. Relationships between these image features and relaxation behavior were evaluated using the instantaneous creep compliance ln[J (0)] and the creep intensity ln [J(3 × 10⁴) ? J (0)]. Although both instantaneous compliance and creep intensity decreased as density increased, their dependence properties were remarkably different. Instantaneous compliance was strongly correlated with R/T ratio and density, which was related to the area ratio, whereas creep intensity was weakly correlated with density in a given range. The results indicate a difference between the two relaxation properties, because creep intensity depends more on microstructures, such as the conformation of molecular chains in the substance, or interactions among cells than on R/T ratio and area ratio image features.