Bidirectional wavelength division multiplexed self-healing ring network composed of a add fiber and a drop fiber

摘要

PURPOSE: A bi-directional WDM(Wavelength Division Multiplexing) self-curable annular network composed of an add optical fiber and a drop optical fiber is provided to maintain a signaling path like a normal state, without the necessity of using an optical switch and an optical fiber for protection, in the event of system failure and to exclude the use of an optical amplifier. CONSTITUTION: The optical signals bi-directionally transmitted from a central node(C0) are modulated into different data respectively through two optical modulators. The two modulated optical signals respectively are connected with two terminals of a 2 x 2 optical switch(SW2). The other two terminals of the 2 x 2 optical switch(SW2) respectively are connected with the input terminals of two MUXs. The 2 x 2 optical switch(SW2) settles the path of each optical signal so that a wavelength signal modulated into priority information can move counterclockwise in a normal state. Accordingly, an optical signal modulated into priority information proceeds along with a drop optical fiber(12) counterclockwise, and the other optical signal proceeds clockwise.