The fundamental technologies for the optical interconnection in the VISI chip have been developed by using conventional Si LSI technologies. The micron-size optical waveguide consisting of Si3N4 core and SiO2 cladding layers has been fabricated by low pressure CVD and atmospheric pressure CVD, respectively. The small size lenses and the light direction converter which changes the light propagation direction from vertical to horizontal fbr the interlayer connection have also been fabricated

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Fundamental technologies for optical interconnection on a Si LSI chip have been developed using conventional silicon process technologies. The optical waveguides with SiO x N y core and SiO2 cladding layers and Al micromirrors to change the light propagation direction have been fabricated by low-temperature deposition. Moreover, the single test chip integrated with a light-emitting diode (LED), photodiode, waveguides and micromirrors has been fabricated and signal transfer between LED and the photodetector has been achieved.

A comprehensive analysis of gened relativistic spacetimes which admit a shearfree, irrotational and geodesic time-like coogruence is presented. The equations governing the models for a gened energy-momentum tensor are wrilten down. Coordinates in which the metric of such spacetimes takes on a simplified form are established. The general subwses of 'zero anisotropic stress', 'zero heat-flux vector' and 'two-component Ruids' are investigated. In particular, perfect-fluid Friedmann-Robertson-Walker models and spatially homogeneous models are discussed. Models with a variety of physically relevant energy-momentum tensors are considered. Anisowopic fluid models and viscous fluid models with heat conduction are examined. Also. models with B perfect Ruid plus a magnetic field or with pure radiation. and models with two non-collinw perfect fluids (satisfying a variety of physical conditions) are inwtigated. In particular. models with a (single) perfect Ruid which is tilting with respect to the shem-free, vorticity-free and acceleration-free time-like congruence are discussed.PACS numbers: 0420J. 9880H