Polarization Insensitive Micro Ring Modulator for Optical Access

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Solution Overview

Problem

Current optical modulators in optical access networks are polarization-dependent, leading to inefficiencies and high power consumption, and require costly polarization maintaining fibers due to their reliance on the polarization orientation of incoming light.

Innovation Solution

A polarization insensitive micro ring modulator (PIMRM) is introduced, which splits incoming light into perpendicular polarization components, rotates one to match the other, and uses a micro ring to modulate both components simultaneously, eliminating polarization dependence and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional polarization-dependent modulators are used, then modulation function is achieved, but polarization maintaining fibers are required and power consumption is high

Engineering Contradiction:
Improvemodulation functionVSAvoidfiber requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The incoming light beam is divided into two separate light beams with orthogonal polarizations using a polarization beam splitter. Each beam is then independently modulated by separate micro rings, allowing the system to process polarization components independently without requiring polarization-maintaining fibers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The modulator is designed to handle multiple polarization states simultaneously through two micro rings that can independently modulate light beams of different polarizations. This universal design eliminates the need for polarization-maintaining fibers while maintaining reliable modulation function across different input polarization states.

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

2Reliability

If traditional polarization-dependent modulators are used, then modulation function is achieved, but power consumption is high

Engineering Contradiction:
Improvemodulation functionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

By segmenting the modulation process into two independent paths for orthogonal polarizations, each micro ring operates more efficiently at lower power levels. The segmentation allows parallel processing without the need for high-power polarization control mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional mechanical or complex electro-optic polarization control mechanisms with passive polarization beam splitting and independent micro ring modulation. This substitution eliminates power-hungry polarization maintenance systems while achieving reliable modulation.

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

3Reliability

If traditional modulators are used, then modulation is achieved, but footprint is large

Engineering Contradiction:
Improvemodulation functionVSAvoidfootprint
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The compact design segments the modulation function into two independent micro rings that can be closely integrated. This segmentation allows for a compact layout where the two polarization paths are processed in parallel within a small area, reducing the overall footprint compared to traditional sequential modulation approaches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the polarization splitting, independent modulation, and recombination functions into a single integrated modulator structure. By combining these functions in one compact unit rather than using separate components, the overall footprint is significantly reduced while maintaining reliable modulation performance.

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

The PIMRM achieves efficient, polarization-independent modulation of multiple wavelengths with lower power consumption and a smaller footprint compared to traditional modulators, enabling cost-effective and high-bandwidth transmission in optical access networks.

Implementation Method 1

a heater coupled to the micro ring... a processor coupled to the monitor photodetector and configured to generate a bias current based on the combined photodetector current, and apply the bias current to the heater such that the temperature of the heater is changed according to the bias current, wherein the temperature of micro ring changes according to the temperature of the heater

Methodology Applied
Scientific EffectThermal effect: Heating

Data Source

PatentEP3615995B1Polarization insensitive micro ring modulator
Publication Date: 2023.04.26 HUAWEI TECH CO LTD
  • EP3615995B1 patent drawingFigure 1~2
  • EP3615995B1 patent drawingFigure 3
  • EP3615995B1 patent drawingFigure 4

AI summary

A transmission-type polarization insensitive modulator implemented as a polarization insensitive micro ring modulator (PIMRM) (200) includes a first polarization splitter-rotator (PSR) (103) configured to generate a first light beam (TE 120) and a second light beam (TE' 123) having a common polarization from an input (102), a micro ring (204) configured to modulate the first light beam (TE 120) with data to generate a first output signal (S130), and modulate the second light beam (TE' 123) with data to generate a second output signal (S' 133), and a second PSR (108) configured to combine the first output signal (S130) and the second output signal (S' 133) to form a modulated output signal, wherein the micro ring (204) is disposed between the first PSR (103) and the second PSR (108).