Waveguide Modifier Layer Structure for PIC Optical Length Tuning

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Solution Overview

Problem

Existing waveguide structures face limitations in flexibility and design due to the need to vary physical dimensions to achieve desired optical lengths, which can complicate the positional arrangement of components in photonic integrated circuits (PICs).

Innovation Solution

The introduction of one or more waveguide modifier layers that modify the effective refractive index for specific modes of light within the waveguide layer, allowing for tuning of optical length without altering the physical dimensions of the waveguide structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the physical dimensions of the waveguide structure are varied to tune the optical length, then the optical length can be adjusted, but the flexibility in PIC design is reduced due to constraints on positional arrangement of components

Engineering Contradiction:
Improveflexibility in PIC designVSAvoidpositional arrangement precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes the refractive index parameter of the waveguide layer by introducing waveguide modifier layers with different refractive indices. This allows tuning of the optical length through material property modification rather than physical dimension changes, thereby maintaining design flexibility without compromising positional arrangement precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures by combining the waveguide layer with waveguide modifier layers. These modifier layers are selectively positioned to modify the effective refractive index, enabling optical length tuning while preserving the physical dimensional constraints needed for precise component arrangement in PICs

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the width or length of the waveguide structure is changed to achieve desired optical length, then the optical path can be tuned, but the device complexity increases due to additional fabrication steps and design constraints

Engineering Contradiction:
Improveoptical length tuning capabilityVSAvoidfabrication process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent modifies the refractive index parameter through the addition of waveguide modifier layers, providing optical length tuning capability without requiring changes to the physical dimensions of the waveguide. This approach reduces fabrication complexity by avoiding additional lithography and etching steps that would be needed to change waveguide geometry

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of tuning optical length by changing the length dimension of the waveguide, the patent introduces modification in the vertical dimension through waveguide modifier layers. This dimensional approach allows optical tuning without affecting the planar footprint and reduces fabrication complexity associated with length adjustments

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

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 provides greater flexibility in PIC design by enabling optical length tuning without changing the physical dimensions of the waveguide, while also allowing for selective modification of refractive index for specific modes of light.

Implementation Method 1

one or more waveguide modifier layers which modify an effective refractive index for certain modes of light in the waveguide layer

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4272029B1Waveguide structure and method of manufacture
Publication Date: 2025.06.18 SMART PHOTONICS HLDG BV
  • EP4272029B1 patent drawingFigure 1
  • EP4272029B1 patent drawingFigure 2
  • EP4272029B1 patent drawingFigure 3

AI summary

A waveguide structure (100) comprising: a substrate (102); a waveguide layer (104) on the substrate (102); a cladding layer (106) in contact with a first side of the waveguide layer (104), the waveguide layer (104) between the cladding layer (106) and the substrate (102); and a first waveguide modifier layer (110) comprising a first material for modifying a waveguide function of the waveguide layer (104), the first waveguide modifier layer (110) in contact with the cladding layer (106) and having a width (W1) along a first axis less than a width (W2) of the cladding layer (106) parallel to the first axis (114), the first axis perpendicular to a second axis (202) corresponding with a light propagation direction within the waveguide layer (104). There is a method of manufacturing a waveguide structure (100).