Vertically Emitting Laser Current-Conducting Layer Segmentation
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Solution Overview
Problem
Radiation-emitting semiconductor lasers with vertical emission direction face challenges in achieving high optical output power and efficient current conduction due to electrical heat losses and the need for precise current conduction designs, which are not scalable between VCSELs and VECSELs.
Innovation Solution
A semiconductor body with a current-conducting layer featuring a current-blocking region and a current-permeable region, where the external resonator volume overlaps with the current-permeable region, allowing for efficient current conduction and radiation generation without hindering radiation outcoupling, utilizing a pn junction for current blocking and dopant-based conduction type reversal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a current constricting layer is used to concentrate operating current in VCSELs, then current conduction is improved, but electrical heat losses negatively impact beam quality and stability
Solution Approach 1:
The current-conducting layer is segmented into a current-blocking region and a current-permeable region. The current-blocking region prevents current flow outside the resonator volume, while the current-permeable region allows efficient current conduction within the resonator volume, thereby improving current conduction efficiency while minimizing electrical heat losses that would degrade beam quality.
Solution Approach 2:
Different regions of the current-conducting layer are assigned different conduction properties. The current-blocking region has properties that prevent current flow, while the current-permeable region has properties that facilitate current flow. This local differentiation allows optimized current conduction within the resonator volume while blocking harmful current paths that generate heat.
2Power
If VCSEL design is transposed to VECSEL with larger lateral dimensions, then optical output power increases, but current conduction design becomes unsuitable
Solution Approach 1:
The current-conducting layer incorporates a current-blocking region that confines current flow to the resonator volume, and a current-permeable region that facilitates efficient current conduction. This local differentiation of conduction properties allows the design to scale from VCSEL to VECSEL while maintaining current conduction efficiency despite increased lateral dimensions.
Solution Approach 2:
The solution transitions from the integrated resonator approach of VCSELs to an external resonator configuration in VECSELs, allowing larger lateral dimensions for higher power output while the current-conducting layer design maintains efficient current conduction through the current-permeable region aligned with the external resonator volume.
3Ease of operation
If electrical contact is disposed inside resonator volume, then current conduction is simplified, but radiation outcoupling is hindered
Solution Approach 1:
The current-conducting layer is segmented into current-blocking and current-permeable regions. The electrical contact is positioned to supply current to the current-permeable region, which is laterally offset from the radiation output region. This segmentation allows simplified current conduction while maintaining efficient radiation outcoupling, as the contact does not obstruct the radiation path.
Solution Approach 2:
The electrical contact is disposed in a different lateral position than the radiation output region. The current-permeable region serves as an intermediate zone that receives current from the contact and directs it to the active layer within the resonator volume, separating the current conduction function from the radiation outcoupling function in the lateral dimension.
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
Enables high output power and improved current conduction efficiency in vertically emitting lasers, ensuring stable and efficient laser operation with reduced technical expenditure by using a structured diffusion method for doping and a concave external resonator for enhanced stability.
Implementation Method 1
The current-blocking region of the current-conducting layer is preferably disposed after the electrical contact in the vertical direction, thereby preventing any flow of current outside the resonator volume of the external resonator that would contribute inefficiently or not at all to the production of radiation
Implementation Method 2
The semiconductor body can be provided with an external resonator to form a vertically emitting laser in which the external resonator has a defined resonator volume that overlaps with the current-permeable region in the current-conducting layer of the semiconductor body
Implementation Method 3
The external resonator mirror is preferably a concavely curved mirror through which, further preferably, the laser radiation is coupled out
Data Source
AI summary
The present invention concerns a radiation-emitting semiconductor body with a vertical emission direction, a radiation-generating active layer, and a current-conducting layer having a current-blocking region and a current-permeable region, the semiconductor body being provided for a vertically emitting laser with an external resonator, and the external resonator having a defined resonator volume that overlaps with the current-permeable region.