Adjustable MMI Waveguide Polarizer for Dynamic Polarization Control

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Solution Overview

Problem

Existing waveguide polarizers can only produce polarized light in a fixed direction, requiring complex systems to split and process optical signals in different polarization states, leading to polarization-dependent loss and mode dispersion in fiber optic communication systems.

Innovation Solution

A polarizer with an MMI multi-mode waveguide and an adjustable portion connected to a controller, allowing the output waveguide to output optical signals in different polarization states by changing material properties such as refractive index, absorption rate, or magnetic conductivity, enabling adjustable polarization without the need for multiple polarizers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed-direction waveguide polarizer is used, then the polarization function is simple, but the system complexity increases when multiple polarization states are required

Engineering Contradiction:
Improvepolarization state output capabilityVSAvoidsystem structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the polarizer's output polarization state adjustable rather than fixed. The waveguide polarizer can dynamically switch between different polarization states (TE and TM modes) based on control signals, allowing a single device to perform multiple functions that would otherwise require multiple fixed polarizers.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements universality by designing a waveguide polarizer that can output optical signals in multiple polarization states. This single multi-functional polarizer replaces what would traditionally require multiple separate polarizers for different polarization states, simplifying the overall system structure while maintaining versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate processing paths are used for different polarization states, then signal processing is complete, but polarization-dependent loss and mode dispersion occur

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoidpolarization-dependent loss and mode dispersion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies merging by combining the processing of different polarization states into a single integrated waveguide path. Instead of separating TE and TM modes into different physical paths where they would experience different losses and dispersion, the invention processes both modes together in the same waveguide structure, eliminating the harmful effects of polarization-dependent loss and mode dispersion.

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 solution allows a single polarizer to output optical signals in both TE and TM polarization states, simplifying the structure and improving signal-to-noise ratio by eliminating the need for separate processing paths, thus enhancing transmission quality in fiber optic communication systems.

Implementation Method 1

the adjustable portion is connected to an output waveguide; and the polarizer further includes a controller connected to the adjustable portion, where the controller is configured to perform control to change a material property of the adjustable portion

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Implementation Method 2

the material property of the adjustable portion includes one or more of the following: a refractive index of the adjustable portion, a magnetic conductivity of the adjustable portion, and a light transmittance of the adjustable portion

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Data Source

PatentEP3073302B1Polarizer and polarization modulation system
Publication Date: 2018.09.26 HUAWEI TECH CO LTD
  • EP3073302B1 patent drawingFigure 1~3
  • EP3073302B1 patent drawingFigure 4~5
  • EP3073302B1 patent drawingFigure 6

AI summary

The present invention provides a polarizer and a polarization modulation system. The polarizer includes at least one MMI multi-mode waveguide, where one side of each MMI multi-mode waveguide is connected to an input waveguide, and the other side is connected to an output waveguide; an end portion of the side, on which the output waveguide is located, of the MMI multi-mode waveguide is provided with an adjustable portion, and the adjustable portion is connected to the output waveguide; and the polarizer further includes a controller connected to the adjustable portion, where the controller is configured to perform control to change a material property of the adjustable portion, so that the output waveguide outputs optical signals in different polarization states. The present invention implements adjustable polarization, and the structure is simple.