Ridge Semiconductor Laser Layout to Limit End-Face COD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor laser element disclosed in existing technologies experiences catastrophic optical damage (COD) near the end faces due to current supply through the P-type contact layer, which extends from one end face to the other, leading to inefficiencies in laser light emission.
Innovation Solution
A semiconductor laser element design featuring a ridge portion and a bottom portion with a current injection window only on the ridge portion, where the P-type contact layer is exposed, and the distance from the active layer to the bottom portion is constant, reducing current leakage and stress concentration near the end faces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the P-type contact layer extends from one end face to the other end face to enable current supply, then current injection is achieved, but catastrophic optical damage (COD) occurs in the vicinity of the end faces
Solution Approach 1:
The P-type contact layer is segmented into two distinct regions: a first P-type contact layer extending from the first end face to the second end face for current injection, and a second P-type contact layer extending only from the active layer to the first end face but not reaching the second end face. This segmentation prevents COD at the second end face while maintaining current supply functionality through the first P-type contact layer.
2Loss of energy
If the P-type contact layer extends to the end faces to enable current supply, then electrical conduction is achieved, but current leakage occurs into non-amplification regions
Solution Approach 1:
Different regions of the P-type contact layer are designed with different extension characteristics: the first P-type contact layer extends to the second end face to enable current supply, while the second P-type contact layer is deliberately restricted from reaching the second end face. This local differentiation ensures current is supplied where needed while preventing leakage into non-amplification regions near the second end face.
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 catastrophic optical damage near the end faces, improving luminous efficiency and preventing laser optical output degradation by minimizing current leakage and carrier diffusion into non-amplification regions.
Implementation Method 1
a semiconductor laser element that emits laser light in a multi-transverse mode... the laser light resonates between the two end faces
Data Source
AI summary
A semiconductor laser element includes a substrate and a semiconductor stack. The semiconductor stack includes an N-side semiconductor layer, an active layer, a P-side semiconductor layer, and a P-type contact layer. The semiconductor stack includes two end faces. Laser light resonates between the two end faces. The semiconductor stack includes: a ridge portion; and a bottom portion surrounding the ridge portion in a top view of the semiconductor stack. The ridge portion protrudes upward from the bottom portion, is spaced apart from the two end faces, and includes at least a portion of the P-type contact layer. A current injection window is provided only on the ridge portion out of a top face of the semiconductor stack, the current injection window being a region into which a current is injected. A distance from a top face of the active layer to the bottom portion is constant.