TOTAL REFLECTION TYPE OPTICAL COUPLING/BRANCHING DEVICE AND METHOD FOR BI-DIRECTION SIMULTANEOUS TRANSMISSION AND RECEPTION OF SINGLE CORE OPTICAL FIBER USING ITS DEVICE

摘要

PURPOSE:To prevent the reduction of the reception efficiency by providing a total reflection mirror having a sectional area smaller than that of a luminous flux on the optical axis. CONSTITUTION:Two converging lenses 1 and 2 are provided on the optical axis corresponding to a T-shaped bar, and a total reflection mirror 3 which is set at 45 deg. to the optical axis and has a sectional area sufficiently smaller than that of parallel rays of the luminous flux due to the converging lens 1 or 2 is arranged at the middle between lenses 1 and 2, namely, at the intersection of the T-shaped bar. A transmission light which passes a converging lens 4 is reflected on the total reflection mirror 3 with about 98% high efficiency. Thought the reception light which passes the converging lens 2 is partially stopped by the total reflection mirror 3, most of this light passes the mirror and the transmission light energy in a reception end is increased if the sectional area of the total reflection mirror 3 is made sufficiently smaller than that of parallel rays of the luminous flux of the reception light. Even if a transparent mirror holder is used to support the total reflection mirror 3, 83% reception efficiency is kept.