Polarization Processing Device for Optical Transceivers

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Solution Overview

Problem

The high cost of polarization maintaining optical fibers used to connect light sources and polarization sensitive modulators in optical modules, due to their expense and the resulting increased costs of optical interconnection solutions.

Innovation Solution

A polarization processing apparatus that converts optical energy in a random polarization state into a single polarization state, allowing for the use of conventional optical fibers instead of polarization maintaining fibers, thereby reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polarization maintaining optical fiber is used to connect light source and modulator, then polarization state stability is improved, but cost increases

Engineering Contradiction:
Improvepolarization state stabilityVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent introduces a polarization processing apparatus as an intermediary device between the light source and the modulator. This apparatus includes a polarization beam splitter, phase shifters, and polarization rotators that work together to convert random polarization state into a stable TE mode polarization state, eliminating the need for expensive polarization maintaining optical fibers while ensuring reliable polarization state stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the polarization state parameter of the light through a series of optical processing steps. By using polarization beam splitting and rotation components, the system transforms the polarization characteristics of the light from random to a controlled TE mode, achieving the desired polarization state stability without requiring special polarization maintaining fibers.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If polarization maintaining optical fiber is used to connect light source pool and modulation unit, then polarization state stability is improved, but device complexity increases

Engineering Contradiction:
Improvepolarization state stabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The polarization processing apparatus serves as a centralized intermediary module that handles polarization state conversion. By consolidating the polarization management function into a single apparatus with standardized components (polarization beam splitter, phase shifters, polarization rotators), the system reduces overall device complexity compared to using multiple polarization maintaining fibers and components throughout the optical path.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The polarization processing apparatus is designed as a universal module that can be applied to connect light sources with various modulation units. The apparatus performs multiple functions including polarization state conversion, beam splitting, and phase adjustment within a single integrated system, reducing the need for multiple specialized components and simplifying the overall device architecture.

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 significantly reduces the costs of optical transmitters and receivers by enabling the use of conventional optical fibers, while maintaining the necessary polarization state for modulators, thus addressing the high cost issue associated with polarization maintaining fibers.

Implementation Method 1

a first polarization beam splitter (PBS) coupled to the input port

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

a first phase shifter (PS) coupled to the first PBS

Methodology Applied
Scientific EffectPhase shifting:

Implementation Method 3

a first polarization rotator (PR) coupled to the first PBS

Methodology Applied
Scientific EffectPolarization rotation:

Data Source

PatentEP3869710B1Polarization processing device and optical transceiver
Publication Date: 2025.02.19 HUAWEI TECH CO LTD
  • EP3869710B1 patent drawingFigure 1~2
  • EP3869710B1 patent drawingFigure 3a
  • EP3869710B1 patent drawingFigure 3b

AI summary

This application discloses a polarization processing optical device, method, and system. In specific implementation, the polarization processing optical device includes a polarization beam splitter (PBS), a polarization rotator (PR), a coupler, and a phase tuner (PT), where one port of the PBS is configured to input a continuous light source, and the other two ports of the PBS are respectively connected to the PR and one port of the coupler; and the PR is connected to another port of the coupler; the PT is disposed on a connection between the PBS and the coupler or a connection between the PR and the coupler; and at least one port of the coupler is configured to output single-polarization light, and the PT is configured to control output optical power of the first coupler. The polarization processing optical device may convert an optical energy in a random polarization state into an optical energy in a single polarization state, and realize optical splitting with a specific proportion. According to the apparatus, an optical transmitter and/or receiver may use a conventional optical fiber to connect a light source and an optical modulator, so that costs are reduced.