Semiconductor Laser Cavity End Face Heat Management via Segmented Current Blocking
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Solution Overview
Problem
Semiconductor laser elements face challenges in minimizing heat generation near the cavity end face, maintaining high COD levels, and achieving a good Far Field Pattern (FFP) shape, especially with high-output elements, due to the difficulties in forming a reliable cavity end face and the impact of current-blocking layers on light confinement.
Innovation Solution
A semiconductor laser element design featuring a laminate structure with a conductive layer and embedded layers, where the conductive layer is positioned inside the groove of the second embedded layer, and the first embedded layer is disposed separately from the conductive layer near the cavity end face, to minimize heat generation and maintain light confinement, thereby improving COD levels and FFP shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the transparent electrode is formed to reach the cavity end face to improve cleavage and orientation properties, then the cavity end face production is improved, but heat generation near the cavity end face increases and COD level drops
Solution Approach 1:
The current blocking layer is divided into two distinct parts: a first current blocking layer positioned away from the cavity end face to block current and reduce heat generation, and a second current blocking layer positioned near the cavity end face to maintain light confinement. This segmentation allows each layer to perform its specific function without compromising the other, resolving the contradiction between heat reduction and light confinement maintenance.
2Object-affected harmful factors
If the transparent electrode is formed farther away from the cavity end face to reduce heat generation and improve COD level, then heat generation is reduced, but the light confinement coefficient changes and FFP shape is disturbed
Solution Approach 1:
The current blocking layer is divided into two distinct parts: a first current blocking layer positioned away from the cavity end face to block current and reduce heat generation, and a second current blocking layer positioned near the cavity end face to maintain light confinement. This segmentation allows each layer to perform its specific function without compromising the other, resolving the contradiction between heat reduction and light confinement maintenance.
3Shape
If the aluminum content of the clad layer is increased to increase the light confinement coefficient, then light confinement is improved, but lattice mismatching causes internal strain and cracking
Solution Approach 1:
Different aluminum content levels are used in different regions of the clad layer. The first clad layer has a lower aluminum content to avoid cracking, while the second clad layer has a higher aluminum content to provide sufficient light confinement near the cavity end face. This local differentiation of material composition allows each region to have the properties needed for its specific function.
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
This design effectively reduces heat generation at the cavity end face, enhances COD levels, and achieves a stable and reliable FFP shape, even with high-output semiconductor laser elements, by ensuring proper light confinement and minimizing current flow to the cavity end face.
Implementation Method 1
a current blocking layer having a stripe-like groove are disposed over the active layer
Implementation Method 2
a method in which the aluminum content of a clad layer is increased has been studied in an effort to sufficiently increase the confinement coefficient of light in the vertical direction
Data Source
Figure 1(a)~1(d)
Figure 2(a)~2(d)
Figure 3(a)~3(b)
AI summary
[Object] The present invention was conceived in light of the above problems, and it is an object thereof to provide a reliable and long-lasting semiconductor laser element with which heat generation near the cavity end face can be kept to a minimum even with high-output semiconductor laser elements, the COD level can be improved, and a good FFP shape can be obtained. [Means for Solving Problem] A semiconductor laser element, comprises: a laminate composed of a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer; and a second embedded layer that is in contact with the second conductivity type semiconductor layer, has a stripe-like groove parallel to the cavity direction, and is composed of an insulator, the groove is embedded with a first embedded layer composed of a dielectric on the cavity end face side, and with a conductive layer on the inside.