Nanowire Quantum Dot Optical Amplifier for Wavelength Correlation Control

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Solution Overview

Problem

Quantum dot semiconductor optical amplifiers face performance issues such as high wavelength correlation, excessively wide covered wave bands, and large noise figures due to random growth positions and sizes of quantum dots using two-dimensional planes as carriers.

Innovation Solution

The use of nanowires with fixed positions as carriers for growing quantum dots, allowing for controlled position and size, reducing fluctuations in alloy components and improving optical performance by embedding quantum dots within the active sections of the nanowires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If two-dimensional parasitic planes are used as carriers for epitaxial growth of quantum dots, then quantum dots can be formed on the plane, but the growth positions and sizes become random and difficult to control, leading to large fluctuations in alloy components

Engineering Contradiction:
Improvecontrol of quantum dot growth position and sizeVSAvoidrandomness of quantum dot formation
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent divides the continuous two-dimensional parasitic plane into discrete, isolated regions by introducing patterned barrier layers. This segmentation creates individually addressable growth sites where quantum dots can be formed at predetermined positions with controlled sizes, eliminating the randomness inherent in continuous plane growth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary patterning of the barrier layers before quantum dot formation. By pre-defining the positions and dimensions of the barrier layer patterns, the subsequent quantum dot growth is constrained to specific locations and sizes, ensuring manufacturing precision without requiring complex in-situ control during the growth process itself.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If quantum dots are grown using two-dimensional parasitic planes as carriers, then quantum dots can be formed, but their positions and sizes are random, causing large wavelength correlation and excessively wide covered wave band

Engineering Contradiction:
Improvewavelength correlation controlVSAvoidcovered wave band width
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by creating spatially varying barrier layer patterns with different dimensions, materials, or compositions at different locations on the substrate. This allows precise control over the quantum dot properties (size, composition, emission wavelength) at each local region, reducing wavelength correlation while enabling targeted coverage of specific spectral bands rather than producing an excessively wide, uncontrolled wave band.

Inventive Principle:
Principle #3Local quality

3Reliability

If quantum dots with random sizes and positions are formed on two-dimensional parasitic planes, then quantum dots can be generated, but the alloy components fluctuate greatly, resulting in large noise figure

Engineering Contradiction:
Improvenoise figureVSAvoidalloy component uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent introduces patterned barrier layers as intermediary structures between the substrate and the quantum dots. These barrier layers act as templates that mediate the quantum dot formation process, constraining the alloy composition and size of quantum dots to predetermined values. This intermediary structure eliminates the direct random growth on the parasitic plane, ensuring uniform alloy components and reducing noise figure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces wavelength correlation, narrows the covered wave band, and decreases the noise figure, enhancing the overall performance of the quantum dot semiconductor optical amplifier.

Implementation Method 1

growing one nanowire along an axial direction of each of the plurality of localization etching holes from a bottom of the localization etching hole

Methodology Applied
Scientific EffectEpitaxial growth: Epitaxy

Data Source

PatentEP3901988B1Quantum dot semiconductor optical amplifier and preparation method therefor
Publication Date: 2024.07.31 HUAWEI TECH CO LTD
  • EP3901988B1 patent drawingFigure 1~3
  • EP3901988B1 patent drawingFigure 4~5
  • EP3901988B1 patent drawingFigure 6

AI summary

This application discloses a quantum dot semiconductor optical amplifier and a preparation method therefor. Because positions of a plurality of localization etching holes on a pre-etching layer (203) are fixed, a position of a nanowire (204) that is from the bottom of the localization etching hole and extends along an axial direction of the localization etching hole is also fixed. In this way, a quantum dot is grown by using the nanowire (204) as a carrier, and a degree of freedom of the growth of the quantum dot is limited, so that the position of the quantum dot is fixed and the size is controllable. Because the position of the quantum dot is fixed and the size is controllable, it is avoided that quantum dots located at a same height in active sections of a plurality of nanowires (204) form a two-dimensional plane. In addition, relatively large fluctuation of alloy components caused by random sizes of the quantum dots can be effectively avoided, thereby reducing wavelength correlation of the amplifier, properly adjusting a width of a covered wave band, and reducing a noise figure.