Monolithic Active-Passive Waveguide Photonic System

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Solution Overview

Problem

The integration of high-quality III-V semiconductor material waveguides on a silicon photonics platform is challenging due to manufacturing and alignment issues, which affects the efficiency of light generation, amplification, and modulation in photonic systems.

Innovation Solution

A monolithic integrated active/passive waveguide photonic system is developed, where III-V semiconductor waveguides are monolithically integrated with silicon waveguides, allowing for evanescent wave coupling between non-overlapping portions, and III-V nanoridge structures are grown within trenches to minimize defects and enhance coupling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If III-V semiconductor waveguides are integrated with silicon waveguides using overlapping configurations, then coupling efficiency is improved, but manufacturing complexity and alignment precision requirements increase significantly

Engineering Contradiction:
Improvecoupling efficiencyVSAvoidalignment precision requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transitions from lateral overlap coupling to vertical evanescent coupling by growing III-V nanoridge structures vertically on silicon waveguides. This dimensional change allows coupling through the vertical interface without requiring precise lateral alignment, thus maintaining coupling efficiency while reducing manufacturing complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The III-V nanoridge structures are grown directly on top of the silicon waveguide structures, creating a nested configuration where the active III-V material is positioned vertically above the passive silicon waveguide. This nesting enables efficient evanescent coupling while simplifying the manufacturing process

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If III-V semiconductor material is grown directly on silicon substrate, then monolithic integration is achieved, but defect density increases due to lattice mismatch

Engineering Contradiction:
Improvemonolithic integrationVSAvoiddefect density
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the III-V structure into nanoridge formations grown within defined regions on the silicon substrate. This segmentation allows controlled growth that minimizes defect propagation while maintaining monolithic integration, as the nanoridge geometry confines the III-V material in a way that reduces the impact of lattice mismatch

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by creating specific nanoridge structures with controlled dimensions and orientations in critical coupling regions. This localized structuring optimizes the interface quality between III-V and silicon materials, reducing defect density in the most critical areas while maintaining overall monolithic integration

Inventive Principle:
Principle #3Local quality

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 enables efficient coupling and minimizes propagation losses, achieving better light generation and absorption efficiencies while allowing for the integration of active and passive functions on a single platform, with low resistance contacts and optimized waveguide configurations.

Implementation Method 1

each of the active waveguide and the passive waveguide being positioned so it does at least partly not overlap with the other waveguide both in height direction as in lateral direction with respect to the substrate in a non-overlapping portion. The waveguides are positioned so that at least part of the evanescent wave coupling occurs between the waveguides at the non-overlapping portion.

Methodology Applied
Scientific EffectEvanescent wave coupling:

Data Source

PatentEP3471221B1Active-passive waveguide photonic system
Publication Date: 2021.06.09 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP3471221B1 patent drawingFigure 1
  • EP3471221B1 patent drawingFigure 2~3
  • EP3471221B1 patent drawingFigure 4

AI summary

The present invention relates to a monolithic integrated active/passive waveguide photonic system, the system comprising a substrate with positioned thereon at least one active waveguide and at least one passive waveguide. The active waveguide and passive waveguide being monolithic integrated and being arranged for evanescent wave coupling between the waveguides, each of the active waveguide and the passive waveguide being positioned so it does at least partly not overlap with the other waveguide both in height direction as in lateral direction with respect to the substrate.