Bidirectional optical communication device and bidirectional optical communication apparatus

摘要

A bidirectional optical communication device satisfies a condition of thetafb<=0<=thetafa or thetafa<=0<=thetafb when thetafa and thetafb are angles of inclination between an optical axis of an optical fiber and transmission light after incidence with a numerical aperture NA at an outermost periphery, and thetafa and thetafb are expressed as the follows: thetafa=Sin-1 [{n0 Sin(thetaL+Sin-1(NA)/n0+thetaT)}/nf]-thetaT thetafb=Sin-1 [{n0 Sin(thetaL-Sin-1(NA)/n0+thetaT)}/nf]-thetaT where nf and no denote refractive indexes of a core of the optical fiber and air, respectively. The bidirectional optical communication device is capable of decreasing restraint of a transmission distance by reducing fluctuation of reception efficiency by the transmission distance and reducing interference between transmission light and reception light.