| 摘要 |
PURPOSE:To improve transmission efficiency by measuring the length of a lead-in wire and controlling the sending timing of an optical signal sent to a normal system based on such a measuring result. CONSTITUTION:An optical taper fiber coupler is used for coupling with an optical bus 11. For example, the optical signal of a constant wavelength is sent from an optical transmitter OS to a lead-in wire 152a coupled through an optical taper fiber coupler 122 to an optical bus 112. This optical signal is folded by the optical taper fiber coupler 122, transmitted in a lead-in wire 152b and received by an optical receiver OR. Then, a transmission time from the transmission of the optical signal to the reception of the signal is counted. Accordingly, when the sending timing of the optical signal sent to a lead-in wire 151a of the normal system is controlled based on the measuring result of the lead-in wires 152a and 152b in an auxiliary system, the optical signal can be securely loaded during an idle time on an optical fiber line 111. In such a case, since the measurement of the lead-in wire is executed in the auxiliary system, the transmission efficiency can be improved. |
