Patent ID: 6529656
Filing Date: 2003-03-04
Classification: G02B,H04B,H04J

Abstract:
A bidirectional add/drop multiplexer comprising,(1) Two wavelength selective couplers (WSC1, WSC2) with an input port (d1 or d2), and output port (f1 or f2), and a common port (e1 or e2); (2) Two optical isolators (Iso1 or Iso2) with an input port (g1 or g2) and an output port (h1 or h2); (3) Two optical circulators (Cir1, Cir2) with an input port (a1 or a2), an output port (c1 or c2) and a common port (b1 or b2); (4) A multiplexing/demultiplexing means with N input/output ports at its both sides; and (5) a mid-stage device composed of a means for compensating the chromatic dispersion of the optical fibers, a means for flattening the spectral responses of the optical amplifiers, a means for suppressing accumulation of the amplified spontaneous emission noise or a combination of these means and wherein, (6) The output ports (f1 or f2) of the wavelength selective couplers (WSC1 or WSC2) are connected to the input ports (a1 or a2) of the optical circulators (Cir1 or Cir2); (7) The input ports (d1 or d2) of the wavelength selective couplers (WSC1 or WSC2) are connected to the output port (h1 or h2) of the optical isolator (Iso1 or Iso2); (8) The input ports (g1 or g2) of the optical isolators (Iso1 or Iso2) are connected to an input/output of the multiplexing/demultiplexing means; (9) the output ports (c1 or c2) of the optical circulators (Cir1 or Cir2) are connected to another input/output port of the multiplexing/demultiplexing means; and (10) The common ports (b1 and b2) of the optical circulators (Cir1 and Cir2) are connected to both ends of the mid-stage device (12).