Patent ID: 6130765
Filing Date: 2000-10-10
Classification: G02B,H04B,H04J

Abstract:
An add/drop device (10) for a multi-wavelength bi-directional optical link, comprising:two main optical circulators (21, 22) each having at least three ports, a first port (211, 223) of said two main circulators correspondingly forming a first connecting port and a second connecting port for said multi-wavelength, bi-directional optical link,a multi-wavelength optical fiber trunk segment (2) connected between second ports (213, 221) of said main circulators,a first additional optical fiber (6) connected to a third port (214) of one of said main circulators, anda second additional optical fiber (7) connected to a third port (224) of the other main circulator,said ports of said main circulators being arranged so as to establish a mono-directional optical path from the first connecting port to the second connecting port via said optical fiber trunk segment,said add/drop device further comprising:two additional optical circulators (23, 24) each having at least three ports;a diversion optical fiber segment (3) connected between said two additional optical circulators;at least one diffraction pattern (4) arranged on said multi-wavelength optical fiber trunk segment for reflecting a first wavelength (.lambda..sub.i), which is to be dropped, received on the first connecting port; andat least one diffraction pattern (5) arranged on said diversion optical fiber segment (3) for reflecting a second wavelength (.lambda..sub.j), which is to be dropped, received on the second connecting port;wherein each additional optical circulator is connected via its first port (234, 244) to one of said additional optical fibers (6, 7) and via its second port to said diversion optical fiber segment so as to establish a mono-directional optical path from said second connecting port to said first connecting port via said diversion optical fiber segment (3).