| 摘要 |
PURPOSE:To correct the ununiformity of an optical signal level from each station by using an active circuit to constitute a star coupler and to eliminate distribution losses substantially. CONSTITUTION:When a station 4i acts like a transmission station, an optical signal outputted from the said station is inputted to an input section 51 in an active star coupler 5, sent to an O/E 52, where the signal is converted into an electric signal and inputted in parallel with a decoder 54 and a signal interruption detection circuit 57. When the signal interruption detection circuit 57 judges the 'presence of signal'. Since an E/O 53i corresponds one to one to the station 4i, the dispersion in line loss between both at them is compensated easily by adjusting the output characteristic of the E/O 53i and nearly the same level of optical signal is supplied to the reception section of each station 4i. |
