3D Optical Waveguide Switch Using PCM Vertical Coupling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Modern microelectronics face challenges with memory bottlenecks, latency, and high power consumption in data transfer between computing chips, necessitating innovative interconnect solutions for higher bandwidth and lower energy consumption.

Innovation Solution

A 3D optical waveguide switch using optical phase change materials (O-PCM) with vertically separated SiN waveguides and a thin O-PCM layer to control optical coupling, reducing optical losses and enabling a flexible crossbar architecture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional electrical interfaces are used for data transfer between computing chips, then data transfer can be achieved, but power consumption is high and latency is significant

Engineering Contradiction:
Improvepower consumptionVSAvoiddata transfer performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces traditional electrical signal transmission with optical signal transmission through waveguides. Light signals carry data between computing chips, eliminating the need for electrical interfaces and reducing power consumption while maintaining high data transfer performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs phase change materials (PCM) that transition between crystalline and amorphous states to control optical switching. These phase transitions enable low-power optical signal modulation and routing, achieving energy-efficient data transfer compared to electrical interfaces.

Inventive Principle:
Principle #36Phase transitions

2Loss of energy

If waveguides are placed in the same plane for optical switching, then device structure is simple, but optical loss is high due to waveguide crossings

Engineering Contradiction:
Improveoptical lossVSAvoidwaveguide structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent transitions from a 2D planar waveguide layout to a 3D vertical architecture. Input and output waveguides are positioned in different vertical planes, allowing optical signals to pass through each other without crossing. This eliminates waveguide intersections and reduces optical loss while managing the complexity through systematic vertical stacking.

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

3Adaptability or versatility

If polysilicon electro-optic material is used to control light coupling, then the switch can operate, but the refractive index change is small requiring ring resonators which reduce spectral width

Engineering Contradiction:
Improveoptical switching capabilityVSAvoidoptical spectral width
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent replaces polysilicon electro-optic material with phase change materials (PCM) that exhibit large refractive index differences between crystalline and amorphous states. This eliminates the need for ring resonators, maintaining broad optical spectral width while enabling effective optical switching control.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent uses composite structures combining PCM layers with dielectric waveguide materials. This composite approach leverages the high refractive index contrast of PCM for strong optical modulation while using dielectric materials for low-loss waveguide propagation, achieving both switching capability and broad spectral operation.

Inventive Principle:
Principle #40Composite materials

4Loss of energy

If 3D vertical waveguide architecture is implemented, then optical loss is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveoptical lossVSAvoidfabrication process
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent implements 3D vertical waveguide stacking with input and output waveguides in different planes. This architecture reduces optical loss by eliminating crossings while using established semiconductor fabrication techniques for systematic manufacturing, balancing performance improvement with fabrication feasibility.

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

Data Source

PatentEP4062213B1Electrically-controllable 3D optical waveguide switch with phase change materials
Publication Date: 2026.02.25 HRL LAB
  • EP4062213B1 patent drawingFigure 1
  • EP4062213B1 patent drawingFigure 2
  • EP4062213B1 patent drawingFigure 3(a)

AI summary

A vertical directional coupler or switch comprising a lower and an upper waveguide, integrated with an optical phase change material disposed between the lower and up-per waveguides to control a directional of optical coupling between the lower and up-per waveguides.