Bidirectional Optoelectronic Device Cross-talk Reduction

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Solution Overview

Problem

Bidirectional optoelectronic devices face significant challenges in reducing cross-talk, which degrades photodetection performance and increases bit error rates due to electrical and optical interference, particularly as device size decreases, leading to substantial cross-talk penalties that affect sensitivity and signal quality.

Innovation Solution

The implementation of a multi-channel optoelectronic device with a protective encapsulant containing hollow dielectric microspheres to reduce electrical cross-talk and an optical absorber to mitigate optical cross-talk, along with a light-trapping structure on a waveguide substrate to manage stray optical signals, and a bipolar drive circuit to minimize electrical cross-talk penalties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If device size is decreased to improve integration, then device compactness is improved, but cross-talk increases degrading photodetection performance

Engineering Contradiction:
Improvedevice sizeVSAvoidphotodetection performance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent introduces an optical absorber as an intermediary substance within the encapsulant material. This absorber intercepts and absorbs stray optical signals before they can reach the photodetector, thereby mediating the cross-talk problem that arises from miniaturized device geometry. The absorber acts as a buffer between the light source and photodetector, preventing direct interference while allowing the device to maintain compact dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite encapsulant material consisting of a base encapsulant matrix combined with dispersed optical absorber particles. This composite structure provides both the protective/structural function of the encapsulant and the optical absorption function of the absorber particles. The composite material enables simultaneous achievement of device compactness and cross-talk reduction by integrating multiple functions into a single material system.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If hollow dielectric microspheres are added to reduce electrical cross-talk, then electrical cross-talk penalty is reduced, but device complexity increases

Engineering Contradiction:
Improveelectrical cross-talk penaltyVSAvoidencapsulant structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent modifies the dielectric properties of the encapsulant material by incorporating hollow dielectric microspheres with specific permittivity characteristics. By changing the effective dielectric constant of the encapsulant through controlled addition of microspheres with known properties, the electrical field distribution is altered to reduce cross-talk. This parameter-based approach allows systematic optimization of electrical performance without requiring complex structural redesign.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality modification by strategically distributing hollow dielectric microspheres within specific regions of the encapsulant. Rather than uniformly complexifying the entire device structure, the microspheres are positioned in areas where electrical field interference is most problematic, providing targeted cross-talk reduction while minimizing overall device complexity. The local application of dielectric modification addresses specific interference zones without affecting the entire device architecture.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If optical absorber is dispersed in encapsulant to reduce optical cross-talk, then optical cross-talk penalty is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveoptical cross-talk penaltyVSAvoidencapsulant fabrication
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent merges the optical absorption function with the encapsulant material itself by dispersing absorber particles within the encapsulant matrix during the encapsulant fabrication process. This merging eliminates the need for separate absorption layers or additional manufacturing steps, as the encapsulant simultaneously provides structural protection and optical absorption. The combined functionality is achieved through single-step fabrication techniques where absorber particles are mixed into the encapsulant material before curing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The encapsulant material performs multiple functions including structural protection, mechanical support, and optical absorption. By incorporating the optical absorber directly into the encapsulant, the encapsulant serves itself to provide both mechanical and optical functions, eliminating the need for separate dedicated absorption components. This self-service approach simplifies manufacturing by reducing the number of discrete components and assembly steps required.

Inventive Principle:
Principle #25Self-service

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 effectively reduces cross-talk penalties to levels below those without these features, maintaining photodetector sensitivity and improving signal quality by minimizing unwanted electrical and optical interference, thereby enhancing the performance of bidirectional optoelectronic devices.

Implementation Method 1

hollow dielectric microspheres dispersed within its volume so as to reduce electrical cross-talk

Methodology Applied
Scientific EffectDielectric constant reduction: Dielectric Permittivity

Implementation Method 2

an optical absorber dispersed within its volume so as to reduce optical cross-talk

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Implementation Method 3

a light-trapping structure formed on a waveguide substrate to manage stray optical signals

Methodology Applied
Scientific EffectLight trapping: Waveguide (optics)

Data Source

PatentEP2614604B1Cross-talk reduction in a bidirectional optoelectronic device
Publication Date: 2017.08.16 HUAWEI TECH CO LTD
  • EP2614604B1 patent drawingFigure 1
  • EP2614604B1 patent drawingFigure 2
  • EP2614604B1 patent drawingFigure 3

AI summary

A multi-channel or bidirectional optoelectronic device comprises a two or more optoelectronic components, e.g., a photodetector and a light source. A protective encapsulant can be applied to the optoelectronic device that includes hollow dielectric microspheres to reduce electrical cross-talk, and that can further include an optical absorber to reduce optical cross-talk.