| 摘要 |
PURPOSE:To eliminate the need for a photodiode for monitoring optical output from an optical transmission section at a subscriber side by controlling the optical output of the optical transmission section at the subscriber side with received power of an optical reception section. CONSTITUTION:An optical output signal outputted from an optical transmission section 10 at the subscriber side is controlled by an optical output control signal resulting from a gain control signal amplified corresponding to the received power of an optical reception section 3. Consequently, when the loss of the optical fiber transmission lines 14, 15 is increased or decreased, the optical output signal of the optical transmission section 10 at the subscriber side is also increased or decreased, the received power of an optical reception section 1 at a station side is made constant. |
