BAND ALTERNATING SYSTEM OF BIDIRECTIONAL ADD/DROP MULTIPLEXER AND OPTICAL AMPLIFIER MODULE SHARING INTERMEDIATE ELEMENT

摘要

PURPOSE: A band alternating system of a bidirectional add/drop multiplexer and an optical amplifier module sharing an intermediate element, are provided to make optical signals progressing bidirectionally share the identical intermediate element, using one NxN arrayed-waveguide grating multiplexer, and to effectively control multiple reflection. CONSTITUTION: Two wavelength selection couplers(WSC1,WSC2) respectively have input ends(d1,d2), output ends(f1,f2), and common input/output ends(e1,e2). Two optical isolators(Iso1,Iso2) respectively have input ends(g1,g2) and output ends(h1,h2). Two optical circulators(Cir1,Cir2) respectively have input ends(a1,a2), output ends(c1,c2), and input/output ends(b1,b2). A bidirectional multiplexing/demultiplexing unit demultiplexes WDMed(Wavelength Division Multiplexed) upward/downward optical signals by wavelength to drop a desired wavelength of optical signal, and multiplexes optical signals passing a corresponding node and optical signals added in the corresponding node to output the multiplexed pass/add optical signals in a progress direction. An intermediate element(12) comprises a unit to compensate color dispersion of an optical fiber, a unit to flatten a gain of an optical amplifier and a unit to control noise accumulation of the optical amplifier, or the combination thereof. The output ends(f1,f2) of the wavelength selection couplers(WSC1,WSC2) are connected to the input ends(a1,a2) of the optical circulators(Cir1,Cir2). The input ends(d1,d2) of the wavelength selection couplers(WSC1,WSC2) are connected to the output ends(h1,h2) of the optical isolators(Iso1,Iso2). The input ends(g1,g2) of the optical isolators(Iso1,Iso2) are connected to the output ends of the bidirectional multiplexing/demultiplexing unit. The output ends(c1,c2) of the optical circulators(Cir1,Cir2) are connected to the input ends of the bidirectional multiplexing/demultiplexing unit and provide the multiplexed downward/upward signals to the bidirectional multiplexing/demultiplexing unit. The input/output ends(b1,b2) of the optical circulators(Cir1,Cir2) are respectively connected to the input/output ends of the intermediate element(12). And simple-stage optical amplifier(SBOA1,SBOA2) amplifying the upward/downward signals simultaneously are connected to the common input/output ends(e1,e2) of the wavelength selection couplers(WSC1,WSC2).