Optical Cross Connection Using Polymer Polarization Gratings

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Solution Overview

Problem

Optical cross connection apparatuses are sensitive to vibration and have low long-term use reliability due to high requirements for lens rotation accuracy in existing MEMS-based systems.

Innovation Solution

The use of polymer polarization gratings (PPGs) and liquid crystals in a switch matrix configuration, where PPGs change the polarization state of light beams, allowing for precise deflection and reduced sensitivity to vibration, combined with a control apparatus to adjust the switches between states, enables efficient optical path routing with improved reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If MEMS-based lens rotation mechanism is used to achieve optical path switching, then optical signal routing capability is improved, but vibration sensitivity increases and long-term reliability decreases

Engineering Contradiction:
Improveoptical path routing capabilityVSAvoidlong-term use reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces the mechanical MEMS lens rotation system with a spatial light modulator (SLM) based optical switching mechanism. The SLM uses phase modulation of light waves to achieve beam deflection without mechanical moving parts, thereby eliminating vibration sensitivity while maintaining optical routing capability. The phase grating written on the SLM creates diffraction patterns that steer light beams to desired output ports without requiring physical lens rotation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a spatial light modulator as an intermediary device between the input optical signals and the output ports. The SLM acts as a programmable phase mask that modulates the wavefront of incoming light, enabling dynamic optical path switching through phase conjugation and diffraction techniques rather than direct mechanical lens manipulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If high precision lens rotation control is implemented to achieve accurate beam deflection, then optical path switching accuracy is improved, but system complexity and vibration sensitivity increase

Engineering Contradiction:
Improvebeam deflection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical lens rotation assemblies with a programmable spatial light modulator that achieves beam deflection through phase modulation. The SLM writes phase gratings directly onto the optical path using diffractive optics, eliminating the need for precision mechanical rotation stages and their associated control systems, thereby reducing overall system complexity while maintaining deflection accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from one-dimensional mechanical lens rotation to two-dimensional phase modulation on the SLM surface. By encoding beam deflection information in the phase domain rather than mechanical angle domain, the system achieves precise control through optical interference patterns without requiring mechanical precision, effectively moving the control mechanism to a different dimensional space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration enhances the reliability and reduces sensitivity to vibration, allowing for stable and efficient optical signal routing with improved miniaturization and reduced complexity, leading to a more robust optical cross connection system.

Implementation Method 1

polymer polarization gratings (PPGs) and liquid crystals in a switch matrix configuration, where PPGs change the polarization state of light beams

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

polymer polarization gratings (PPGs) and liquid crystals in a switch matrix configuration

Methodology Applied
Scientific EffectLiquid crystals: Liquid Crystals

Data Source

PatentEP3324226B1Optical cross connection apparatus
Publication Date: 2021.10.27 HUAWEI TECH CO LTD
  • EP3324226B1 patent drawingFigure 1~2
  • EP3324226B1 patent drawingFigure 3~4
  • EP3324226B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention disclose an optical cross connection apparatus. The apparatus in the embodiments of the present invention includes x input ports, y output ports, a first switch matrix, a second switch matrix, and a control apparatus, where y is greater than or equal to x; the first switch matrix includes x×m switches in a matrix arrangement, where x switches of the first column are configured to receive polarized light beams from the x input ports respectively; the second switch matrix includes y×n switches in a matrix arrangement, where the y output ports are configured to receive light beams from y switches of the last column respectively; the x input ports each have a corresponding output port; and the control apparatus is configured to control a switch when it is determined that the jth input port is corresponding to the kth output port, so that a light beam output from the jth input port successively passes through switches of the jth row of the first switch matrix and switches of the kth row of the second switch matrix, and is incident to the kth output port at a preset angle.