OPTICAL COMMUNICATION SYSTEM AND ADJUSTMENT METHOD OF THEM

To maintain a high reliability and suppress a cost.SOLUTION: In an optical communication system, a first optical transmitter-receiver (1a or 1b) sequentially transmits a first optical signal by a plurality of first optical output powers at the time of an adjustment of the first optical transmitter-receiver (1a or 1b), and a second optical transmitter-receiver (1b or 1a) sequentially receives the first optical signal, the second optical transmitter-receiver (1b or 1a) acquires a first relation between the plurality of first optical output powers and a plurality of first reception sensitivities by measuring the plurality of first reception sensitivities of the first optical signal which sequentially receives. A first range of the first optical output power of which an error ratio becomes a predetermined value or less on the basis of a first relation is calculated. A first adjustment result signal indicating the first range calculated is transmitted to the first optical transmitter-receiver. The first optical transmitter-receiver (1a or 1b) sets the first optical output power of the first optical signal in their operation period to a value calculated on the basis of the first adjustment result signal.SELECTED DRAWING: Figure 2 【課題】高い信頼性を維持しつつ、コストを抑制する。【解決手段】光通信システムにおいて、第１の光送受信器（１ａ又は１ｂ）の調整時に、第１の光送受信器（１ａ又は１ｂ）は、第１の光信号を複数の第１の光出力パワーで順次送信し、第２の光送受信器（１ｂ又は１ａ）は、第１の光信号を順次受信し、第２の光送受信器（１ｂ又は１ａ）は、順次受信した第１の光信号の複数の第１の受信感度を測定して複数の第１の光出力パワーと複数の第１の受信感度との間の第１の関係を取得し、第１の関係に基づいて誤り率が予め決められた値以下になる第１の光出力パワーの第１の範囲を算出し、算出された第１の範囲を示す第１の調整結果信号を第１の光送受信器に送信し、第１の光送受信器（１ａ又は１ｂ）は、その運用期間における第１の光信号の第１の光出力パワーを第１の調整結果信号に基づいて計算された値に設定する。【選択図】図２