Reconfigurable optical add and drop multiplexer system with integrated wavelength selective switch array

1 . A reconfigurable optical add and drop multiplexer (ROADM) system, comprising:

a multiplexer;

a demultiplexer; and

a switching system configured to route optical signals through the ROADM, wherein the switching system comprises:

a first wavelength selective switch (WSS) optically coupled to a tapping coupler and the demultiplexer and configured to receive an input optical signal from a first circulator, transmit a drop optical signal to the demultiplexer to drop one or more first wavelength channels, and output a through optical signal;

a second WSS optically coupled to the first WSS and the multiplexer and configured to receive an add optical signal from the multiplexer to add one or more second wavelength channels, receive the through optical signal from the first WSS, and output an output optical signal to a second circulator;

an optical channel monitor (OCM) configured to monitor the input optical signal received by the first WSS and the output optical signal output by the second WSS,

wherein the first WSS, the second WSS, and the OCM each comprise one or more input optical ports configured to receive optical signals and one or more output optical ports configured to output optical signals, and

wherein the first WSS, the second WSS, and the OCM include a set of shared optics configured to direct optical signals from the one or more input optical ports to the one or more output optical ports.

2 . The ROADM system of claim 1 , wherein the first circulator and the second circulator are a same bi-directional circulator.

3 . The ROADM system of claim 1 ,

wherein directing the optical signals from the one or more input optical ports to the one or more output optical ports comprises spatially separating wavelength channels of the optical signals.

4 . The ROADM system of claim 1 , wherein the set of shared optics comprises:

a polarization conditioning system configured to separate the optical signals received at the one or more input optical ports into a first polarization and a second polarization orthogonal to the first polarization; and

a dispersion system configured to spatially separate the optical signals received at the one or more input optical ports into respective wavelength channels.

5 . The ROADM system of claim 1 , wherein the OCM comprises a Mux WSS and a photodiode detector (PD) optically coupled to the Mux WSS.

6 . The ROADM system of claim 1 , wherein the set of shared optics comprises polarization conditioning optics, polarization switching optics, a port switch direction cylindric lens, a dispersion cylindric spectrum lens, and a spectrum dispersion component.

7 . The ROADM system of claim 1 , wherein the first WSS comprises a first Demux WSS and a second Demux WSS, the second WSS comprises a first Mux WSS and a second Mux WSS, and the OCM comprises a first OCM and a second OCM,

wherein the first Demux WSS is optically coupled to the tapping coupler and is configured to receive the input optical signal from the first circulator, transmit the drop optical signal to the demultiplexer to drop the one or more first wavelength channels, and output the through optical signal to the first Mux WSS,

wherein the first Mux WSS is optically coupled to the first Demux WSS and is configured to receive the add optical signal from the multiplexer, receive the through optical signal from the first Demux WSS, and output the output optical signal to the second circulator, and

wherein the first OCM is optically coupled to the tapping coupler and a second tapping coupler and is configured to monitor the input optical signal received by the first Demux WSS and the output optical signal output by the first Mux WSS.

8 . The ROADM system of claim 7 , further comprising:

a second multiplexer; and

a second demultiplexer,

wherein the second Demux WSS is optically coupled to a third tapping coupler and is configured to receive a second input optical signal from the second circulator, transmit a second drop optical signal to the second demultiplexer to drop the one or more first wavelength channels, and output a second through optical signal to the second Mux WSS,

wherein the second Mux WSS is optically coupled to the second Demux WSS and is configured to receive a second add optical signal from the second multiplexer, receive the second through optical signal from the second Demux WSS, and output a second output optical signal to the first circulator, and

wherein the second OCM is optically coupled to the third tapping coupler and a fourth tapping coupler and is configured to monitor the second input optical signal received by the second Demux WSS and the second output optical signal output by the second Mux WSS.

9 . The ROADM system of claim 7 , wherein each of the first Demux WSS, the second Demux WSS, the first Mux WSS, the second Mux WSS, the first OCM, and the second OCM corresponds to a respective subset of the one or more input optical ports and the one or more output optical ports.

10 . The ROADM system of claim 9 , wherein the respective subsets are arranged in two rows and three columns.

11 . The ROADM system of claim 1 , wherein the set of shared optics comprises a liquid crystal (LC) polarization switching array comprising a first row of pixel array and a second row of pixel array, and

wherein each row of pixel array comprises three switch controlling sections, and each switch controlling section comprises a plurality of LC elements.

12 . The ROADM system of claim 7 , wherein;

the set of shared optics comprises a liquid crystal (LC) polarization switching array comprising a first row of pixel array and a second row of pixel array,

the first row of pixel array comprises three switch controlling sections respectively configured to control the first Demux WSS, the first Mux WSS, and the first OCM, and

the second row of pixel array comprises three switch controlling sections respectively configured to control the second Demux WSS, the second Mux WSS, and the second OCM.

13 . The ROADM system of claim 12 , wherein the three switch controlling sections of the first row of pixel array and the three switch controlling sections of the second row of pixel array are arranged in three different columns.

14 . A switching system, comprising:

a first wavelength selective switch (WSS) optically coupled to a tapping coupler and configured to receive an input optical signal from a first circulator, transmit a drop optical signal to a demultiplexer to drop one or more first wavelength channels, and output a through optical signal;

a second WSS optically coupled to the first WSS and configured to couple to a multiplexer, receive an add optical signal from the multiplexer to add one or more second wavelength channels, receive the through optical signal from the first WSS, and output an output optical signal to a second circulator;

a optical channel monitor (OCM) configured to monitor the input optical signal received by the first WSS and the output optical signal output by the second WSS;

wherein the first WSS, the second WSS, and the OCM each comprise one or more input optical ports configured to receive optical signals and one or more output optical ports configured to output optical signals, and

wherein the first WSS, the second WSS, and the OCM include a set of shared optics configured to direct optical signals from the one or more input optical ports to the one or more output optical ports.

15 . The switching system of claim 14 , wherein the first circulator and the second circulator are a same bi-directional circulator.

16 . The switching system of claim 14 , wherein directing the optical signals from the one or more input optical ports to the one or more output optical ports comprises spatially separating wavelength channels of the optical signals.

17 . The switching system of claim 14 , wherein the set of shared optics comprises:

a dispersion system configured to spatially separate the optical signals received at the one or more input optical ports into respective wavelength channels; and

a polarization conditioning system configured to separate the optical signals received at the one or more input optical ports into a first polarization and a second polarization orthogonal to the first polarization.

18 . The switching system of claim 14 , wherein the OCM comprises a Mux WSS and a photodiode detector (PD) optically coupled to the Mux WSS.

19 . The switching system of claim 14 , wherein the set of shared optics comprises polarization conditioning optics, polarization switching optics, a port switch direction cylindric lens, a dispersion cylindric spectrum lens, and a spectrum dispersion component.

20 . The switching system of claim 14 , wherein the first WSS comprises a first Demux WSS and a second Demux WSS, the second WSS comprises a first Mux WSS and a second Mux WSS, and the OCM comprises a first OCM and a second OCM,

wherein the first Demux WSS is optically coupled to the tapping coupler and is configured to receive the input optical signal from the first circulator, transmit the drop optical signal to the demultiplexer to drop the one or more first wavelength channels, and output the through optical signal to the first Mux WSS,

wherein the first Mux WSS is optically coupled to the first Demux WSS and is configured to receive the add optical signal from the multiplexer, receive the through optical signal from the first Demux WSS, and output the output optical signal to the second circulator,

wherein the first OCM is optically coupled to the tapping coupler and a second tapping coupler and is configured to monitor the input optical signal received by the first Demux WSS and the output optical signal output by the first Mux WSS,

wherein the second Demux WSS is optically coupled to a third tapping coupler and is configured to receive a second input optical signal from the second circulator, transmit a second drop optical signal to a second demultiplexer to drop the one or more first wavelength channels, and output a second through optical signal to the second Mux WSS,

wherein the second Mux WSS is optically coupled to the second Demux WSS and is configured to receive a second add optical signal from a second multiplexer, receive the second through optical signal from the second Demux WSS, and output a second output optical signal to the first circulator, and

wherein the second OCM is optically coupled to the third tapping coupler and a fourth tapping coupler, and is configured to monitor the second input optical signal received by the second Demux WSS and the second output optical signal output by the second Mux WSS.