Semiconductor Laser Current Shielding for High-Power Efficiency
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Solution Overview
Problem
Existing semiconductor laser elements have insufficient power conversion efficiency, limiting their effectiveness in high-power applications.
Innovation Solution
A semiconductor laser element design featuring a first region with a diffraction grating and a second region allowing laser light to propagate in multiple transverse modes, accompanied by a current shielding structure with controlled current injection through opening regions, reducing heat generation and enhancing power conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If current is injected into the first region including the diffraction grating, then the laser can operate, but heat generation increases and power conversion efficiency decreases
Solution Approach 1:
The patent segments the current injection path by introducing a current shielding structure with opening regions that selectively block current flow. The current is divided and injected only through specific opening regions rather than uniformly across the entire first region, thereby reducing heat generation in non-essential areas while maintaining laser operation through controlled current injection into the active layer.
Solution Approach 2:
The current shielding structure creates local variations in current density by providing opening regions with different areas and positions. This allows optimized current distribution where current is concentrated in regions that contribute most to laser generation while being excluded from regions that would generate excessive heat, thus improving overall power conversion efficiency.
2Power
If current density is increased to achieve higher power output, then laser power increases, but heat generation increases and damages the stripe side
Solution Approach 1:
The current shielding structure segments the current injection area into multiple opening regions, distributing the total current across several localized paths. This segmentation prevents excessive current density concentration that would cause thermal damage to the stripe side, while still achieving the required total power output through coordinated current injection across all opening regions.
Solution Approach 2:
The current shielding structure acts as an intermediary between the current source and the semiconductor layered portion. It mediates the current distribution by blocking current in certain areas and allowing it in others, thereby preventing direct excessive current injection into regions susceptible to thermal damage while maintaining overall laser power output.
3Measurement precision
If the width of the first region is increased to accommodate the diffraction grating, then wavelength selection is improved, but the area increases and current injection complexity increases
Solution Approach 1:
The current shielding structure is segmented into opening regions that correspond to the functional zones within the first region. This segmentation allows the diffraction grating to span the required width for precise wavelength selection while the current is injected only through specific opening regions, avoiding the need for complex current distribution across the entire enlarged first region area.
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 design achieves high power conversion efficiency by minimizing heat generation in the first region, enabling efficient high-power laser operation with reduced current density and improved luminous efficiency.
Implementation Method 1
a first region (1) including a diffraction grating (105)
Implementation Method 2
a current shielding structure (10) provided at a position overlapping the first region (1) in a top view, and including one or more opening regions (140a) for injecting a current into the semiconductor layered portion (101) in the first region (1)
Data Source
AI summary
A semiconductor laser element includes: a semiconductor layered portion including an active layer and having a waveguide structure, wherein the semiconductor layered portion includes: a first region including a diffraction grating, and a second region including a core region, and cladding regions located on both sides of the core region, the second region allowing laser light to propagate in a plurality of transverse modes. A width of the first region is greater than a width of the core region in a direction in which the core region and the cladding region are arranged. A current shielding structure is located at a position overlapping the first region in a top view, and includes one or more opening regions for injecting a current into the semiconductor layered portion in the first region. A total area of the one or more opening regions is smaller than an area of the first region in a top view.