| 摘要 |
PURPOSE:To realize an optical access node which extracts and receives necessary information from signal light and transmits the sent signal light to a next node as it is by providing a means which demodulates a signal to be selected and received from the voltage variation of one terminals of a semiconductor optical amplifier. CONSTITUTION:This system has the semiconductor optical amplifier 1, a local oscillation light source 2, an optical fiber coupler 3, a bias circuit 4, an amplifier 5, and a demodulating circuit 6. In this case, when the signal light 10 and local oscillation light 11 are sufficiently close in frequency, the terminal voltage 7 of the semiconductor optical amplifier 1 varies corresponding to the beats of the signal light 10 and local oscillation light 11. The variation of the terminal voltage 7 is amplified by the amplifier 5 and then demodulated by the demodulated circuit 6 by applying a demodulation system corresponding to the modulation system of the signal light 10 to extract the information from the signal light 10. Consequently, the optical access node is realized which extracts and receives the necessary information from the signal light 10 and received and transmits the sent signal light 10 to the next node as it is. |
