Silicon-on-Insulator Polarization Controller with MZI Stages

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Solution Overview

Problem

Existing polarization controllers for photonic integrated circuits require time-consuming and costly alignment of external optical components, necessitating a cost-effective and efficient solution for dynamic polarization state transformation.

Innovation Solution

A compact automatic endless polarization controller for silicon-on-insulator platforms, utilizing a polarization rotator splitter, Mach-Zehnder interferometer stages, and phase shifters to split and phase-delay optical beams, ensuring a fixed target polarization output with minimal external alignment, and an optical tap for power measurement to adjust control signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If external polarization components are used to construct a polarization controller, then polarization control function is achieved, but alignment and assembly time and cost increase

Engineering Contradiction:
Improveassembly timeVSAvoidnumber of external components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges multiple external polarization control components into a single integrated photonic circuit chip. The polarization controller combines waveplate structures, phase shifters, and couplers that were previously separate external components into one unified device fabricated on a photonic platform, eliminating alignment and assembly operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces mechanical alignment and assembly operations with photonic integration techniques. Instead of physically aligning multiple external optical components, the solution uses photonic waveguide structures and optical couplers integrated on a chip to achieve the same polarization control function, substituting mechanical processes with photonic integration.

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

2Ease of manufacture

If multiple off-chip optical components are aligned, then polarization control is achieved, but cost increases

Engineering Contradiction:
Improvemanufacturing costVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple polarization control functions into a single integrated photonic circuit. By merging waveplate structures, phase shifters, and couplers onto one chip, the solution reduces the total number of components that need to be purchased, handled, and assembled, thereby reducing manufacturing cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses photonic integration to create a scaled-down, integrated version of the polarization controller. The integrated photonic circuit replicates the function of multiple external optical components in a compact form factor, reducing material costs and assembly expenses.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If a polarization controller is designed for dynamic polarization transformation, then polarization control performance is improved, but device complexity increases

Engineering Contradiction:
Improvepolarization transformation capabilityVSAvoidnumber of control elements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent incorporates dynamic control elements including voltage-controlled phase shifters and tunable couplers that can dynamically adjust polarization states. These dynamic components enable the polarization controller to adapt to different polarization requirements while being integrated on a single photonic chip.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent designs a universal polarization controller that can perform multiple polarization transformation functions using a set of integrated photonic elements. The device can handle various polarization states and transformation requirements through a compact set of waveguide structures and control mechanisms.

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

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

The solution provides a cost-effective, compact, and efficient means to achieve a fixed target polarization output, reducing alignment needs and enabling rapid polarization tracking with low insertion loss and power consumption, suitable for photonic integrated circuits.

Implementation Method 1

a polarization rotator splitter (PRS) for splitting the input optical beam into first and second feeds corresponding to the first and second orthogonal polarization components

Methodology Applied
Scientific EffectPolarization splitting: Polarisation

Implementation Method 2

a first phase shifter coupled to the PRS for providing a first optical phase delay between the first and second feeds based on a first control signal

Methodology Applied
Scientific EffectPhase delay: Phase Modulation

Implementation Method 3

a first 2x2 optical coupler coupled to the first phase shifter for mixing the first and second feeds having the first optical phase delay therebetween

Methodology Applied
Scientific EffectOptical mixing: Interference

Data Source

PatentEP3796056B1Automatic endless polarization controller for a silicon-on-insulator platform
Publication Date: 2024.08.28 HUAWEI TECH CO LTD
  • EP3796056B1 patent drawingFigure 1
  • EP3796056B1 patent drawingFigure 2
  • EP3796056B1 patent drawingFigure 3

AI summary

A photonic platform based polarization controller (1000) for providing a fixed target polarization of an optical beam (1005) having first and second orthogonal polarization components, the polarization controller (1000) comprising: a polarization rotator splitter (PRS) (1100); a first Mach-Zehnder interferometer (MZI) stage (1200) coupled to the PRS (1100); a second MZI stage (1300) coupled to the first MZI stage (1200); a third MZI stage (1400) coupled to the second MZI stage (1300); and an optical tap (1510). Provided an inexpensive polarization controller.