An optical transmission module includes plural optical transmission means
(optical waveguides) whose end portions are exposed on a first end face
thereof, and at least one of an optical transmitting section and an
optical receiving section to each of which some of the optical
transmission means are optically coupled. The remaining optical
transmission means are exposed on a second end face opposed to the first
end face. Only some of the plural optical transmission means are designed
to have a communication facility at some position in the longitudinal
direction thereof, while the remaining optical transmission means are
designed to have the communication facility by being connected to
post-stage optical transmission modules in the longitudinal direction. By
multistage-connecting these optical transmission modules, plural optical
transmission means and optical transmission modules can be collectively
connected at a narrow frontage.
