Frequency extractor
AssigneeAlcatel
InventorsSabry Khalfallah, Denis Penninckx
Life of this patent
Estimating the term…
Abstract
A selective frequency extractor is disclosed which forwards one or more selected frequencies of a wavelength division multiplex input signal consisting of N channels to one output port and all the other frequencies to another output port. A reconfigurable frequency add and drop multiplexer is also disclosed. The input signal is divided up by a first demultiplexer and routed to a plurality of interleaved stages of optical switches for selectively feeding a plurality of input ports of a multiplexer, whose routing properties are then used for extracting one or more frequencies from the input signal or for reconfigurable frequency add and drop multiplexing.
Claims6
A selective frequency extractor for forwarding one or more selected frequencies of a wavelength division multiplex input signal consisting of N channels to one output port and all other frequencies to another output port, which extractor includes:
- a demultiplexer having at least one input port and at least N output ports:
- for any value of i from 1 to N, the ith output port of said demultiplexer is adapted to receive the corresponding ith frequency of said input signal,
- a multiplexer having at least N+1 input ports and at least two output ports:
- for any value of i from 1 to N, the ith input port of said multiplexer is adapted to forward the ith frequency of said input signal to a first output port of said multiplexer, and for any value of i from 2 to N+1, the ith input port of said multiplexer is adapted to forward the (i−1)th frequency of said input signal to a second output port of said multiplexer, and
- optical switches for selectively connecting any ith output port of said demultiplexer, for i from 1 to N, either to said ith input port of said multiplexer or to said (i+1)th input port of said multiplexer.
A reconfigurable frequency add and drop multiplexer, including:
- a demultiplexer having at least two input ports for receiving two wavelength division multiplexes consisting of N channels, and at least N+2 output ports:
- for all values of i from 1 to N, the ith output port of said demultiplexer is adapted to receive the corresponding ith frequency of a first multiplex received at said first input port, and for any value of i from 3 to N+2, said ith output port of said demultiplexer is adapted to receive the (i−2)th frequency of the second multiplex received at said second input port,
- a multiplexer having at least N+1 input ports and at least two output ports:
- for any value of i from 1 to N, the ith input port of said multiplexer is adapted to forward the ith frequency to a first output port of said multiplexer, and for any value of i from 2 to N+1, an ith input port of said multiplexer is adapted to forward the (i−1)th frequency to a second output port of said multiplexer, and
- optical switches for selectively connecting any ith output port of said demultiplexer, for i from 3 to N, to the (i−1)th input port of said multiplexer, or to the ith input port of said multiplexer, or to the (i+1)th input port of said multiplexer, the first and second output ports of said demultiplexer being each respectively connected to the first and second input ports and to the second and third input ports of said multiplexer, and the (N+1)th and (N+2)th output ports of said demultiplexer being each connected respectively to the Nth input ports and to the (N+1)th input port of said multiplexer.
Dependencies are inferred from the claim text.