US 12,231,832 B2Granted

Method for pre-calculating and applying optimized phase patterns to LCoS switch panel of WSS module

AssigneeII-Vi Delaware, Inc.

InventorsAlan A. Fennema, Haijun Yuan, Wilfredo C. Nanita, Oswald Correya, Jack R Kelly, Thomas J. Schwartz

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Abstract

Advanced hologram techniques pre-calculate holograms to be displayed on an LCoS switch panel of a wavelength selective switch (WSS) module. The holograms are generated offline and are then stored on the WSS module for later retrieval. Each of the holograms is associated with a defined parameter, such as an attenuation level, and each of the holograms is configured to create a reconfigurable phase grating profile or pattern of the pixels of the LCoS switch panel. Each phase pattern selectively directs desired diffraction orders of optical channels from the LCoS switch panel for output to selected ports and selectively directs undesired diffraction orders away from the ports and at a desired attenuation level. During operation, the WSS module can retrieve the stored holograms. Interpolation can determine intermediate holograms between parameter values, and a ramp function can be added to the pattern to account for steering adjustments.

Claims25

Dependent claims

An apparatus for processing an input beam, the apparatus comprising:

a plurality of ports being separated by port spacing, at least one of the ports being configured to transmit the input beam;
a dispersion element arranged in optical communication with the input beam from the at least one port and configured to disperse the input beam into optical channels;
a switch assembly arranged in optical communication with the optical channels from the dispersion element, the switch assembly being liquid crystal based and having a plurality of pixels, the pixels being individually addressable;
and
control circuitry arranged in operational communication with the switch assembly, the control circuitry storing a plurality of holograms, each of the holograms associated with a defined parameter, each of the holograms configured to create a reconfigurable phase grating profile of the pixels of the switch assembly, each of the reconfigurable phase grating profiles being configured to selectively direct a portion of one or more diffracted beams of one or more of the optical channels from the switch assembly relative to one or more of the ports, the control circuitry being configured to select at least one of the holograms based on the defined parameter and being configured to control the switch assembly based on the at least one selected hologram;
wherein the defined parameter is selected from the group consisting of a targeted attenuation level for the optical channels, a wavelength range for the optical channels, a geometric alignment of the ports of the apparatus, a steering gradient, and an operating temperature of the apparatus.

3 more elements

An apparatus for processing an input beam, the apparatus comprising:

a plurality of ports being separated by port spacing, at least one of the ports being configured to transmit the input beam;
a dispersion element arranged in optical communication with the input beam from the at least one port and configured to disperse the input beam into optical channels;
a switch assembly arranged in optical communication with the optical channels from the dispersion element, the switch assembly being liquid crystal based and having a plurality of pixels, the pixels being individually addressable;
and
control circuitry arranged in operational communication with the switch assembly, the control circuitry storing a plurality of holograms, each of the holograms associated with a defined parameter, each of the holograms configured to create a reconfigurable phase grating profile of the pixels of the switch assembly, each of the reconfigurable phase grating profiles being configured to selectively direct a portion of one or more diffracted beams of one or more of the optical channels from the switch assembly relative to one or more of the ports, the control circuitry being configured to select at least one of the holograms based on the defined parameter and being configured to control the switch assembly based on the at least one selected hologram;
wherein the control circuitry is configured to:
obtain a current parameter associated with the apparatus;
find at least one of the holograms stored in memory having the defined parameter that is at least associated with the current parameter;
and
retrieve the at least one hologram found in memory;
and wherein the control circuitry comprises an interpolation module being configured to:
select at least two of the stored holograms having the defined parameters associated on both sides of the current parameter;
interpolate an intermediate hologram between the at least two selected holograms;
and
control the switch assembly based on the intermediate hologram.

12 more elements

A method for processing an input beam, the method comprising:

transmitting the input beam from at least one port of a plurality of ports, the ports being separated by port spacing;
dispersing the input beam into optical channels with a dispersion element;
storing a plurality of holograms, each of the holograms associated with a defined parameter, each of the holograms configured to create a reconfigurable phase grating profile of individually addressable pixels of a switch assembly;
selecting at least one of the holograms based on the defined parameter;
and
selectively directing a portion of one or more diffracted beams of one or more of the optical channels relative to one or more of the ports by individually addressing the pixels of the switch assembly according to the at least one selected hologram;
wherein selecting at least one of the holograms based on the defined parameter comprises:
select at least two of the holograms having the defined parameters associated on both sides of an intermediate value;
interpolating an intermediate hologram between at least two selected holograms;
and
controlling the switch assembly based on the intermediate hologram.

8 more elements

A method of configuring a module to process an input beam, the method comprising:

modeling a plurality of ports and a switch assembly of the module, the switch assembly arranged in optical communication with optical channels, the switch assembly being liquid crystal based and having a plurality of pixels, the pixels being individually addressable;
determining a plurality of holograms for operating the switch assembly, each of the holograms associated with a defined parameter and each configured to create a reconfigurable phase grating profile of the pixels, by iteratively simulating diffractions of the optical channels from the switch assembly with the reconfigurable phase grating profile, comparing each of the simulated diffractions against a target performance at the defined parameter, and adjusting the reconfigurable phase grating profile of the pixels based on the comparison;
and
storing the plurality of determined holograms with the defined parameters associated therewith as data accessible by the module;
wherein determining the plurality of holograms comprises:
selecting at least two of the holograms having the defined parameters associated on both sides of an intermediate value;
interpolating an intermediate hologram between at least two selected holograms;
comparing the simulated diffractions for the intermediate hologram against the target performance at the intermediate;
and
accepting the at least two holograms for storage based on the comparison.

7 more elements

Dependencies are inferred from the claim text.