G02B 2006/2839

Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals {forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using lateral coupling between contiguous fibres to split or combine optical signals formed or shaped by thermal treatment, e.g. couplers fabricated from double or twin core fibres}