Heat Spreader Layer for Optical Component Thermal Management
Solution Overview
Problem
Conventional edge couplers in photonics chips, particularly those with silicon waveguide cores, are susceptible to irreversible power-related damage due to poor power handling capabilities, leading to thermal heating and potential physical melting at high optical input powers.
Innovation Solution
Incorporating a heat spreader layer with high thermal conductivity, such as diamond, positioned between the substrate and the waveguide core to dissipate heat generated during operation, thereby reducing the operating temperature and preventing permanent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a silicon waveguide core is used in an edge coupler, then the device can be fabricated with good manufacturing compatibility, but the power handling capability deteriorates due to thermal heating and physical melting at high optical input powers
Solution Approach 1:
A heat spreader layer is introduced as an intermediary component between the silicon waveguide core and the substrate. This heat spreader layer mediates the thermal management by conducting heat away from the waveguide core, preventing thermal accumulation while maintaining the silicon-based fabrication process. The heat spreader acts as a thermal conduit that separates the manufacturing benefits of silicon from its thermal management drawbacks.
Solution Approach 2:
The device structure transitions from a homogeneous silicon waveguide core to a composite structure combining silicon waveguide core with a heat spreader layer having different thermal properties. This composite approach allows the silicon portion to provide manufacturing compatibility while the heat spreader material (such as diamond or other high thermal conductivity materials) provides superior thermal management, thereby resolving the contradiction between ease of manufacture and reliability.
2Power
If optical input power is increased to enhance system performance, then the signal strength is improved, but thermal heating increases causing physical melting of the waveguide core
Solution Approach 1:
The patent converts the harmful thermal effect of high optical power into a manageable parameter by introducing the heat spreader layer. The heat generated by high optical input power, which would normally cause melting, is now channeled through the heat spreader layer to the substrate. This transforms the harmful thermal accumulation into a controlled heat flow path, allowing high power operation without temperature-induced damage.
3Productivity
If the waveguide core cross-sectional area is reduced to improve coupling efficiency, then the mode transformation is enhanced, but the power handling capability deteriorates due to increased thermal density
Solution Approach 1:
The heat spreader layer provides localized thermal management specifically at the waveguide core region where heat generation is most intense. By placing the heat spreader in direct thermal contact with the waveguide core, the solution addresses the local thermal density issue created by the reduced cross-sectional area, allowing the waveguide to maintain its efficient coupling geometry without suffering from excessive thermal accumulation.
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 heat spreader layer effectively mitigates thermal issues, allowing the waveguide core to operate within acceptable temperature limits, relaxing restrictions on laser power levels and enhancing system performance by preventing hotspots and physical damage.
Implementation Method 1
the heat spreader layer comprises a second material having a second thermal conductivity that is greater than the first thermal conductivity of the first material
Data Source
AI summary
Structures including an optical component and methods of fabricating a structure including an optical component. The structure includes a substrate, an optical component including a waveguide core, and a back-end-of-line stack including a heat spreader layer. The optical component is positioned in a vertical direction between the substrate and the back-end-of-line stack. The waveguide core contains a first material having a first thermal conductivity, and the heat spreader layer contains a second material having a second thermal conductivity that is greater than the first thermal conductivity of the first material.