LCOS Optical Switching with Synchronized Multi-Channel Blocking

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Solution Overview

Problem

Conventional wavelength selective switches (WSS) in reconfigurable optical add-drop multiplexers (ROADM) networks experience frequent power fluctuations due to independent phase adjustments of LCOS pixels, leading to inaccurate power control and reduced operating stability.

Innovation Solution

Implementing attenuation adjustments for multiple wavelength channels using consecutive images, where each image includes sub-images for each channel, allowing simultaneous switching to a blocking state to minimize power fluctuations and improve power control accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent phase adjustment of LCOS pixels is performed for each wavelength channel, then wavelength switching and port blocking functions are achieved, but frequent power fluctuations occur in the multiplexing optical signal

Engineering Contradiction:
Improvewavelength switching capabilityVSAvoidpower stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent merges the phase adjustment operations of multiple wavelength channels into a unified process. By determining a unified target phase for all pixels based on the blocking requirements of multiple channels simultaneously, the system achieves port blocking for multiple wavelengths in one coordinated action rather than through separate independent adjustments, thereby eliminating frequent power fluctuations.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If independent phase adjustment of LCOS pixels is performed for each wavelength channel, then wavelength channel control is achieved, but accurate power control of optical components is degraded

Engineering Contradiction:
Improvewavelength channel controlVSAvoidpower control accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent performs preliminary determination of a unified target phase for all pixels based on the blocking requirements of multiple wavelength channels before executing the phase adjustment. This preliminary coordination ensures that the phase adjustment is optimized for simultaneous multi-channel blocking, preventing power fluctuations and enabling accurate power control of downstream optical components.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple attenuation adjustments are performed for switching wavelength channels to blocking state, then wavelength channel switching is achieved, but operating stability of non-scheduling services is compromised

Engineering Contradiction:
Improveport blocking functionVSAvoidservice operating stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent combines multiple attenuation adjustment operations into a single coordinated phase adjustment process. By calculating a unified target phase that satisfies the blocking requirements of multiple wavelength channels simultaneously, the system achieves port blocking for all channels in one action rather than through multiple sequential adjustments, thereby maintaining service stability.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method reduces frequent power fluctuations, enhances power control accuracy, and improves the operating stability and performance of WSS in ROADM networks.

Implementation Method 1

Each pixel can be independently adjusted. However, in a conventional technology, phase adjustment of pixels that are in an LCOS and that correspond to wavelengths is independently performed

Methodology Applied
Scientific EffectPhase modulation: Phase Modulation

Implementation Method 2

a lens group and a grating in the WSS perform spatial separation on wavelengths in the multi-wavelength multiplexing signal

Methodology Applied
Scientific EffectSpatial separation: Dispersion (of waves)

Implementation Method 3

generating K images that are consecutive in time sequence, where the first wavelength channel and the second wavelength channel are switched to a blocking state through a same image in the K images

Methodology Applied
Scientific EffectLiquid crystal phase control: Liquid Crystals

Implementation Method 4

each of the K images includes a first sub-image and a second sub-image, the first sub-image indicates an attenuation adjustment value of the first wavelength channel, and the second sub-image indicates an attenuation adjustment value of the second wavelength channel

Methodology Applied
Scientific EffectOptical attenuation: Absorption (EM radiation)

Data Source

PatentEP4054095B1Optical switching method and apparatus, and liquid crystal on silicon and wavelength selective switch
Publication Date: 2025.10.29 HUAWEI TECH CO LTD
  • EP4054095B1 patent drawingFigure 1~2
  • EP4054095B1 patent drawingFigure 3
  • EP4054095B1 patent drawingFigure 4

AI summary

This application provides an optical switching method and apparatus, applied to an optical communication network, an optical switching network, and a digital center network. The method includes: generating K images that are consecutive in time sequence, where a first wavelength channel and a second wavelength channel are switched to a blocking state through a same image in the K images, and a value of K depends on a quantity of times that attenuation adjustment is performed for switching the first wavelength channel from a normal state to the blocking state; and sending information about the K images to an optical switching element, to enable the optical switching element to perform attenuation adjustment on the first wavelength channel and the second wavelength channel. Attenuation adjustment for switching at least two wavelength channels to the blocking state is implemented based on a same image, so that the at least two wavelength channels can be simultaneously switched to the blocking state, to avoid frequent power fluctuation that is of a multiplexing optical signal and that is caused by switching the at least two wavelength channels to the blocking state at different moments, and improve stability of an optical communication system.