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US 2003/0197919 A1Published application
Interleaving combiner for a bidirectional wavelength-division multiplexing system
AssigneeLucent Technologies Inc.
InventorStojan Radic
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AssigneeLucent Technologies Inc.
InventorStojan Radic
Estimating the term…
An interleaving combiner (ILC) that may be used to implement hybrid amplification in a bidirectional interleaved wavelength-division multiplexing (WDM) system. The ILC implements a composite pump/signal combining and interleaving filtering function in a single topology characterized by relatively low insertion losses. In a preferred form, the ILC is a four-port device that is configured to (i) route bidirectional optical signals corresponding to different communication channels to and from unidirectional lumped optical amplifiers and (ii) combine those signals with a pump signal for distributed amplification in a fiber span between different lumped amplifiers. The ILC provides relatively high rejection for the pump signal along optical paths different from the intended one and relatively low in- and out-of-band crosstalk for the communication channels. The ILC may be implemented using a Gires-Tournois interferometer.
An interleaving combiner (ILC), comprising at least four ports, wherein:
An amplifier for use in a bidirectional wavelength-division multiplexing (WDM) system, the amplifier comprising:
An interleaving combiner (ILC), comprising:
Dependencies are inferred from the claim text.
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For multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM: interleaving or deinterleaving, i.e. separating or…
As bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters: cascade of polarisation selective or…
Operating by wave or beam interference: michelson or Michelson/Gires-Tournois configuration, i.e. based on splitting and interferometrically…
Arrangements specific to fibre transmission: bidirectional transmission
Term end not estimated
1. Field of the Invention
The present invention relates to optical communication equipment and, more specifically, to bidirectional wavelength-division multiplexing (WDM) systems.
2. Description of the Related Art
Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which:
FIG. 1 shows an exemplary bidirectional interleaved WDM system of the prior art;
FIG. 2 illustrates representative channel allocation that may be used in the system of FIG. 1;
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Interleaving Filter
FIG. 3A illustrates possible mechanisms of in- and out-of-band crosstalk in bidirectional interleaved WDM system 100 of FIG. 1. An optical fiber coupled to an optical amplifier (e.g., fiber span 110A or 110B coupled to gain block 120A) may act as a distributed Rayleigh mirror, e.g., due to small variations in the index of refraction along the fiber length. Consequently, a small fraction of an optical signal propagating in one direction in the fiber is reflected in the opposite direction.