Asymmetric Waveguide Multiport Photonic Device

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Solution Overview

Problem

Current optical devices face polarization-dependent effects such as PDL, which cause signal distortion due to unequal power levels for different polarization states, and existing solutions to mitigate this either compromise bandwidth or increase device size.

Innovation Solution

The use of multiport photonic devices with asymmetric waveguide cross-sectional areas, where waveguides with different cross-sectional areas couple to share the same active region, eliminating polarization-dependent loss (PDL) while maintaining high bandwidth and reducing device size by ensuring equal absorption coefficients for both waveguide modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate optical components and distinct optical paths are used for different polarization states, then polarization dependent loss is mitigated, but bandwidth capabilities are affected and device size increases

Engineering Contradiction:
Improvepolarization dependent loss mitigationVSAvoidbandwidth capabilities
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges the handling of different polarization states into a single shared optical path and active region. Two waveguides with orthogonal polarization modes are coupled to share the same active region, eliminating the need for separate optical paths while maintaining equal absorption coefficients for both polarization states, thus preserving bandwidth capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The active region is designed to serve multiple functions simultaneously: it absorbs light from both waveguides with orthogonal polarizations with equal efficiency. This universal absorption capability allows a single component to handle multiple polarization states without requiring separate dedicated components for each polarization.

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

2Reliability

If separate optical components and distinct optical paths are used for different polarization states, then polarization dependent loss is mitigated, but device size increases

Engineering Contradiction:
Improvepolarization dependent loss mitigationVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the handling of different polarization states into a single shared optical path and active region. Two waveguides with orthogonal polarization modes are coupled to share the same active region, eliminating the need for separate optical paths while maintaining equal absorption coefficients for both polarization states, thus preserving bandwidth capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The active region is designed to serve multiple functions simultaneously: it absorbs light from both waveguides with orthogonal polarizations with equal efficiency. This universal absorption capability allows a single component to handle multiple polarization states without requiring separate dedicated components for each polarization.

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

3Reliability

If waveguides with different cross-sectional areas are used, then absorption coefficients are equalized for both polarization states, but waveguide geometry becomes asymmetric

Engineering Contradiction:
Improveabsorption coefficient equalizationVSAvoidwaveguide geometry symmetry
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent intentionally introduces asymmetry in waveguide geometry by using waveguides with different cross-sectional areas. This asymmetric design is specifically engineered to equalize the absorption coefficients for both polarization states, demonstrating that controlled geometric asymmetry can achieve optical performance symmetry.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent changes the geometric parameters of the waveguides by varying their cross-sectional areas. By adjusting these physical dimensions, the absorption coefficients for different polarization modes are equalized, showing how parameter optimization can resolve optical performance issues.

Inventive Principle:
Principle #35Parameter changes

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 approach allows for compact optical devices with uniform responsivity for different polarization states, maintaining high bandwidth and low return loss by ensuring that waveguides with different cross-sectional areas have the same absorption coefficients, thus eliminating PDL and enhancing the performance of photonic integrated circuits.

Implementation Method 1

an absorption region to absorb light from the first and the second waveguides

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Data Source

PatentEP2879250B1Multiport photonic device with asymmetric waveguides
Publication Date: 2022.10.05 OPENLIGHT PHOTONICS INC
  • EP2879250B1 patent drawingFigure 1A
  • EP2879250B1 patent drawingFigure 1B
  • EP2879250B1 patent drawingFigure 2A

AI summary

Embodiments describe optical devices including a first waveguide, comprising a first cross-sectional area, to receive a light comprising a first optical mode, and a second waveguide, adjacent to the first waveguide, to receive a light comprising a second optical mode orthogonal to the first optical mode. The second waveguide comprises a second cross-sectional area different than the first waveguide such that an absorption/gain coefficient of the second waveguide for light comprising the second optical mode is equal to an absorption/gain coefficient of the first waveguide for light comprising the first optical mode. The optical devices may comprise modulators, photodetectors, or semiconductor optical amplifiers (SOAs).