Thermal Management of Ridge-Type Hybrid Laser

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Solution Overview

Problem

Thermal management of small-scale integrated devices, particularly photonic integrated circuits, is hindered by high heat flux levels and poor thermal resistance, leading to inefficient operation and increased energy consumption, which limits the integration density and bandwidth requirements for exaflop computing.

Innovation Solution

A ridge-type hybrid laser with a thermally conductive, electrically insulating coating is used to efficiently transfer heat away from the laser, reducing thermal resistance and maintaining electrical isolation, thereby improving thermal management and operational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polymer encapsulation (BCB) is used to attach III-V materials to silicon substrates, then electrical isolation and dielectric properties are improved, but thermal resistance increases significantly

Engineering Contradiction:
Improveelectrical isolationVSAvoidthermal resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The encapsulation structure is segmented into multiple functional layers: a bottom polymer layer (BCB) for electrical isolation and bonding, and a top thermally conductive layer for heat dissipation. This segmentation allows each layer to optimize its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device employs a composite encapsulation structure combining polymer materials (for electrical isolation) with thermally conductive materials (for heat management). This composite approach integrates the beneficial properties of different material classes to simultaneously address electrical and thermal requirements.

Inventive Principle:
Principle #40Composite materials

2Productivity

If device integration density is increased to meet bandwidth requirements, then communication capacity is improved, but heat flux density increases leading to thermal management issues

Engineering Contradiction:
ImprovebandwidthVSAvoidheat flux density
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

A thermally conductive encapsulation layer acts as an intermediary between the heat-generating laser device and the silicon substrate, facilitating efficient heat transfer while maintaining electrical isolation. This intermediary structure enables high-density integration by managing the thermal load.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The solution addresses thermal management by introducing a vertical thermal conduction path through the encapsulation layers, moving heat management from a planar constraint to a three-dimensional solution with dedicated thermal pathways.

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

3Use of energy by moving object

If laser operational temperature is reduced to improve efficiency and spectral output, then energy consumption decreases, but thermal management complexity increases

Engineering Contradiction:
Improveenergy consumptionVSAvoidthermal management
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The thermally conductive encapsulation layer provides passive, continuous heat dissipation without requiring active cooling systems or complex thermal management circuitry. The structure itself performs the thermal management function through its inherent thermal conductivity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The encapsulation material parameters are specifically selected to optimize thermal conductivity while maintaining electrical isolation properties. By changing the thermal parameters of the encapsulation layer, the system achieves improved heat dissipation without increasing complexity.

Inventive Principle:
Principle #35Parameter changes

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 significantly reduces thermal resistance, allowing for better temperature control and improved spectral output efficiency, enabling more efficient heat transfer and reduced energy consumption, thus enhancing the performance and reliability of photonic integrated circuits.

Implementation Method 1

a thermally conductive, electrically insulating coating adjacent a surface of the ridge-type hybrid laser; the coating being configured to transfer heat away from the laser

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2866316A1Thermal management of a ridge-type hybrid laser, device, and method
Publication Date: 2015.04.29 ALCATEL LUCENT SA
  • EP2866316A1 patent drawingFigure 1(a)~1(b)
  • EP2866316A1 patent drawingFigure 2
  • EP2866316A1 patent drawingFigure 3(a)~3(b)

AI summary

Aspects and embodiments relate to a device and method for providing a device. The device comprises: a ridge-type hybrid laser; and a thermally conductive, electrically insulating, coating adjacent a surface of the ridge-type hybrid laser; the coating being configured to transfer heat away from the laser. It will be appreciated that aspects and embodiments recognise that a thermal solution can be implemented to enable energy efficient, scalable, reliable and low cost cooling designs for integrated photonics devices. An arrangement in accordance with aspects and embodiments described herein can provide improved thermal performance of a hybrid ridge type laser device. Such improved thermal performance can facilitate better temperature control, and lower device temperature can result in better device performance and longer device lifetimes. Aspects and embodiments help to provide an integrated thermal approach which can deal with thermal spreading close to where heat on a device is generated within a laser waveguide.