The assembly has a hollow fiber bundle with a plurality of hollow fiber membranes.

A unitized optical fiber bundle (9), a unitized bundle of light guiding optical fibers, is provided on the inner surface of the housing (3).

An optical cable (50) is branched into optical fiber bundles at the main branching section, and each fiber bundle is branched into single-core optical fibers at the sub-branching section.

The optical coupling unit includes a main fiber channel (11) formed of a single fiber or a bundle of fibers, a sub-fiber channel (12) formed of a bundle of many fine fibers.

The invention relates to a filter device comprising two flow chambers, wherein a first chamber is formed by the tube passageways of the fibers of a bundle of hollow fibers and a second chamber is formed by a housing (10) framing the hollow fiber bundle.