Edge-Emitting Laser Bar Thermal Decoupling Between Emitters
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Solution Overview
Problem
Existing AlInGaN-based edge-emitting laser bars suffer from high failure rates due to heat-induced failures in adjacent emitters, which are exacerbated by the low activation of acceptors and differences in behavior compared to GaAs-based laser bars, leading to inefficient power distribution and facet damage.
Innovation Solution
Incorporating a thermal decoupling structure between individual emitters with a cooling element that is electrically isolated from the semiconductor layer sequence, using materials like SiC or DLC for insulation, to prevent heat exchange and facilitate efficient heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional laser bar structure without thermal decoupling is used, then the device complexity is low, but heat exchange between adjacent emitters causes high failure rates and facet damage
Solution Approach 1:
The laser bar structure is segmented into electrically isolated regions between adjacent emitters. Insulating layers are introduced to divide the continuous semiconductor structure into discrete electrical zones, preventing current leakage and heat exchange between emitters while maintaining structural integrity.
Solution Approach 2:
An insulating layer acts as an intermediary element between adjacent emitters. This intermediate layer provides electrical isolation and thermal decoupling, preventing direct interaction between neighboring emitter regions while allowing the overall laser bar to function as an integrated device.
2Reliability
If acceptor activation is improved in AlInGaN-based semiconductor, then the electrical performance is enhanced, but heat generation increases leading to facet damage
Solution Approach 1:
Heat is extracted and isolated from the active emitter regions through insulating layers. By removing the thermal coupling between adjacent emitters, the harmful heat that would otherwise propagate to facets and cause damage is contained and managed separately from the electrical function.
Solution Approach 2:
The thermal pathways are segmented through insulating barriers. This segmentation prevents heat accumulation and transfer between adjacent emitters, allowing each emitter to be optimized for electrical performance without compromising neighboring regions through thermal interference.
3Reliability
If electrical insulation is introduced between emitters, then heat exchange is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The insulating layer serves multiple functions simultaneously: it provides electrical insulation, thermal decoupling, and structural support. By merging these functions into a single integrated layer, the manufacturing process is simplified compared to introducing separate components for each function.
Solution Approach 2:
The insulating layer is designed to perform multiple roles within the laser bar structure. It acts as an electrical insulator, thermal barrier, and mechanical support element, reducing the need for additional specialized components and simplifying the overall manufacturing process.
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 thermal decoupling structure effectively reduces heat transfer between emitters, preventing facet damage and increasing the reliability and efficiency of AlInGaN-based laser bars.
Implementation Method 1
the cooling element is electrically isolated from the semiconductor layer sequence and thermally coupled to the semiconductor layer sequence
Implementation Method 2
the cooling element is electrically isolated from the semiconductor layer sequence along the cooling region
Data Source
AI summary
In an embodiment an edge-emitting laser bar includes an AlInGaN-based semiconductor layer sequence having a contact side and an active layer, a plurality of individual emitters arranged next to each other and spaced apart from one another in a lateral transverse direction, a plurality of contact elements arranged next to each other and spaced apart from one another in the lateral transverse direction on the contact side for making electrical contact with the individual emitters, and a thermal decoupling structure in a region between two adjacent individual emitters, wherein the decoupling structure includes an electrically conductive cooling element located on the contact side and completely covering a contiguous cooling region of the contact side, wherein the cooling element is completely electrically isolated from the semiconductor layer sequence and thermally coupled to the semiconductor layer sequence along the cooling region, and wherein the cooling region has a width, measured along the lateral transverse direction, which is at least half a width of an adjacent contact region.