Laser Diode Adhesion Layer for Emission Angle Control
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Solution Overview
Problem
Existing laser diodes face challenges in defining a small lateral emission angle range for electromagnetic radiation, which is crucial for high-power operation and efficient coupling into optical waveguides.
Innovation Solution
A laser diode design featuring a layer arrangement with a metallic adhesion layer and contact layer, where the adhesion layer's thickness and structure are specifically configured to control the lateral emission angle range, allowing for a reduced and defined emission angle by using materials like titanium and structuring the adhesion layer into partial surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional planar adhesion layer is used, then the electrical contact is simple and reliable, but the lateral emission angle range cannot be controlled or reduced
Solution Approach 1:
The adhesion layer is divided into multiple partial surfaces (first partial surface and second partial surface) with different functions. The first partial surface provides adhesion to the semiconductor layer, while the second partial surface provides adhesion to the contact layer and controls the lateral emission angle range through its specific structure and material composition.
Solution Approach 2:
Different regions of the adhesion layer are assigned different materials and structures to achieve different local functions. The first partial surface uses one material composition for basic adhesion, while the second partial surface uses a different material composition specifically engineered to control the lateral emission angle range.
2Reliability
If the adhesion layer is made thicker to improve adhesion, then electrical contact reliability improves, but the lateral emission angle range increases which is undesirable
Solution Approach 1:
The adhesion layer is segmented into functional zones where the second partial surface can be made thicker to control emission angle without compromising the overall adhesion strength provided by the first partial surface.
Solution Approach 2:
The second partial surface uses specific materials with different optical and adhesive properties that allow thickness optimization for angle control while the first partial surface maintains adhesion reliability.
Data Source
AI summary
A laser diode includes an active zone that emits radiation in a lateral emission angle range in a plane of the active zone via an emission side of a layer arrangement, an electrical contact is configured on a top side of the layer arrangement, the electrical contact includes a metallic adhesion layer and at least one metallic contact layer, the adhesion layer is arranged on the layer arrangement, the adhesion layer includes a layer stack including a first and a second layer, the first layer is arranged on the layer arrangement, the first layer is configured in a planar fashion, the second layer is subdivided into at least one first and at least one second partial surface, the adhesion layer is arranged in the first partial surface, and the contact layer is arranged on the first partial surface and in the second partial surface.