The present invention provides a system that includes a plurality of cache engines coupled to a computer network such as the Internet, and a cache memory associated with each of the plurality of cache engines. The bearing mechanism has a shaft support recess in which the shaft is inserted and a plurality of shaft restriction projections provided projecting from the wall surface of the shaft support recess, and the shaft restricting projections have a cross section arc shaped shaft support surface such that there is contact with a portion of the outer periphery of the shaft. If the waveguide structure has positive PDL, for example, the output fibre may be aligned with the TE mode axis to reduce TE coupling loss relative to TM coupling loss, thus inducing a negative coupling PDL. The bonded component is positioned adjacent to the first surface, and the bonded component is thermal bonded to the first surface with the thermoplastic polymer material of the fusible yarn.