Compact wavelength-selective cross-connect device having multiple input ports and multiple output ports
A wavelength-selective cross-connect (WSXC) device having N input ports and M output ports and configured to route any set of one or more carrier wavelengths from a corresponding input port to any selected output port. In one embodiment, the WSXC device includes a diffraction grating and a beam-steering device optically coupled to each other and to the input/output ports so that each of the carrier wavelengths traverses the diffraction grating and the beam-steering device two or more times en route from the respective input port to a designated output port. Various unfolded configurations of the WSXC device are also disclosed.
1. An apparatus, comprising:
a first plurality of ports;
a second plurality of ports;
a first diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a first beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein:
each port of the first plurality is configured to receive a respective input WDM signal having two or more respective WDM components;
the apparatus is configured to variously route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components traverses the first diffraction grating and the first beam-steering device;
the first diffraction grating is configured to spectrally disperse light received from the first plurality of ports and direct spectrally dispersed light to the first beam-steering device;
the first beam-steering device is configurable to individually steer beams corresponding to different wavelength bands of the spectrally dispersed light received from the first diffraction grating to enable the apparatus to route any of the WDM components from the respective port of the first plurality to any port of the second plurality; and
the apparatus has a folded structure that causes a WDM component to traverse the first diffraction grating four times.
2. The apparatus of claim 1 , wherein the first plurality of ports and the second plurality of ports have at least one port in common.
3. The apparatus of claim 2 , further comprising an optical circulator connected to a first of said common ports and configured to separate an output WDM signal applied to the first common port from the input WDM signal received by the first common port.
4. The apparatus of claim 1 , wherein the folded structure causes the WDM component to traverse the first beam-steering device two times.
5. The apparatus of claim 4 , further comprising a curved mirror configured to direct light between the first diffraction grating and the first beam-steering device so that the WDM component traverses the mirror eight times.
6. The apparatus of claim 1 , wherein the ports of the first plurality are arranged in a two-dimensional array.
7. The apparatus of claim 6 , wherein the ports of the second plurality are arranged in a two-dimensional array.
8. The apparatus of claim 1 , wherein the ports of the second plurality are arranged in a two-dimensional array.
9. The apparatus of claim 1 , wherein the first beam-steering device comprises a two-dimensional pixelated MEMS mirror array.
10. The apparatus of claim 9 , wherein at least one mirror in said array is configured to tilt around two different axes.
11. The apparatus of claim 1 , wherein the first beam-steering device comprises a pixelated liquid-crystal-on-silicon micro-display.
12. An apparatus, comprising:
a first plurality of ports;
a second plurality of ports;
a first diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a first beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein:
each port of the first plurality is configured to receive a respective input WDM signal having two or more respective WDM components;
the apparatus is configured to variously route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components traverses the first diffraction grating and the first beam-steering device;
the first diffraction grating is configured to spectrally disperse light received from the first plurality of ports and direct spectrally dispersed light to the first beam-steering device; and
the first beam-steering device is configurable to individually steer beams corresponding to different wavelength bands of the spectrally dispersed light received from the first diffraction grating to enable the apparatus to route any of the WDM components from the respective port of the first plurality to any port of the second plurality;
a second diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a second beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein the apparatus is further configured to route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components also traverses the second diffraction grating and the second beam-steering device; and
wherein the apparatus has a folded structure that causes a WDM component to traverse each of the first diffraction grating and the second diffraction grating two times.
13. The apparatus of claim 12 , wherein, for each port of the second plurality:
the second beam-steering device is configured to reduce angular diversity among optical beams that carry the WDM components routed to the port; and
the second diffraction grating is configured to remove spectral dispersion of said optical beams.
14. The apparatus of claim 12 , further comprising:
a first curved mirror configured to direct light between the first diffraction grating and the first beam-steering device so that the WDM component traverses the first mirror four times; and
a second curved mirror configured to direct light between the second diffraction grating and the second beam-steering device so that the WDM component traverses the second mirror four times.
15. An apparatus, comprising:
a first plurality of ports;
a second plurality of ports;
a first diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a first beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein:
each port of the first plurality is configured to receive a respective input WDM signal having two or more respective WDM components;
the apparatus is configured to variously route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components traverses the first diffraction grating and the first beam-steering device;
the first diffraction grating is configured to spectrally disperse light received from the first plurality of ports and direct spectrally dispersed light to the first beam-steering device; and
the first beam-steering device is configurable to individually steer beams corresponding to different wavelength bands of the spectrally dispersed light received from the first diffraction grating to enable the apparatus to route any of the WDM components from the respective port of the first plurality to any port of the second plurality;
a second diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a second beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein the apparatus is further configured to route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components also traverses the second diffraction grating and the second beam-steering device; and
wherein the second diffraction grating has nominal spectral-dispersion characteristics that are different from nominal spectral-dispersion characteristics of the first diffraction grating.
16. An apparatus, comprising:
a first plurality of ports;
a second plurality of ports;
a first diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a first beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein:
each port of the first plurality is configured to receive a respective input WDM signal having two or more respective WDM components;
the apparatus is configured to variously route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components traverses the first diffraction grating and the first beam-steering device;
the first diffraction grating is configured to spectrally disperse light received from the first plurality of ports and direct spectrally dispersed light to the first beam-steering device; and
the first beam-steering device is configurable to individually steer beams corresponding to different wavelength bands of the spectrally dispersed light received from the first diffraction grating to enable the apparatus to route any of the WDM components from the respective port of the first plurality to any port of the second plurality;
a second diffraction grating interposed between the first plurality of ports and the second plurality of ports;
a second beam-steering device interposed between the first plurality of ports and the second plurality of ports, wherein the apparatus is further configured to route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components also traverses the second diffraction grating and the second beam-steering device;
a third diffraction grating interposed between the first plurality of ports and the second plurality of ports; and
a fourth diffraction grating interposed between the first plurality of ports and the second plurality of ports, wherein the apparatus is further configured to route the WDM components from the first plurality of ports to the second plurality of ports so that each of the WDM components also traverses the third diffraction grating and the fourth diffraction grating.
17. The apparatus of claim 16 , wherein:
the first and third diffraction gratings have identical nominal spectral-dispersion characteristics; and
the second and fourth diffraction gratings have identical nominal spectral-dispersion characteristics.
18. The apparatus of claim 17 , wherein the nominal spectral-dispersion characteristics of the first and third diffraction gratings are different from the nominal spectral-dispersion characteristics of the second and fourth diffraction gratings.