| 摘要 |
PURPOSE:To attain ease of high-order line extension by providing the 2nd optical synthesizer synthesizing a synthesized optical signal from the 1st optical synthesizer at the transmission side at the extension of line and synthesizing an extension line optical wavelength signal and providing the 2nd optical branching filter at the reception side to increase the number of multiplex. CONSTITUTION:In an example of this execution, the optical synthesizer and the optical branching filter 2 used for two-wave existing multiplex optical transmission system are used as they are and an optical synthesizer 7 and an optical branching filter 8 are arranged newly at both ends of an optical fiber cable. As the optical synthesizer 7 and the optical branching filter 8, short wavelength passing filters 40 are used. The light 1a having wavelength lambda1(=850mum) and wavelength lambda2(=890mum) irradiated from the optical synthesizer 1 passes through the filter 40, the light having a wavelength lambda3(=1,300mum) transmitted from an optical transmitter 9 is reflected and its synthesized wave is transmitted through an optical fiber cable 100. Further, the optical branching filter 8 reflects the light of wavelength lambda3, transmits the light of wavelengths lambda1, lambda2 and leads them to the optical receiver 10 and the optical branching filter 2 as lights 10a, 2a respectively. |
