VCSEL Oxide Aperture Structure for Current Confinement Reliability
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Solution Overview
Problem
Existing vertical cavity surface-emitting lasers (VCSELs) face issues with high energy consumption, reliability deterioration due to cracks in semiconductor layers, and performance degradation from foreign matter, along with challenges in maintaining light straightness and luminous efficacy.
Innovation Solution
A light emitting device with a first and second mirror layer, a cavity layer, and oxidized layers forming an aperture, where the oxidized layers are strategically designed to control electric current flow and protect against cracks and foreign matter, while enhancing light emission through refractive index layers and insulating layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If etching and oxidation methods are used to form an isolated post to confine electric current to a small area, then current confinement is improved, but the semiconductor layer becomes vulnerable to cracks and foreign matter penetration
Solution Approach 1:
The patent introduces an insulating layer as an intermediary substance that fills the isolated post structure. This insulating layer acts as a mediator that maintains the current confinement function while simultaneously protecting the semiconductor layer from cracks and foreign matter penetration, thus resolving the contradiction between manufacturing precision and reliability
Solution Approach 2:
The insulating layer is formed beforehand to fill the isolated post structure before the semiconductor layer is fully processed. This prior cushioning provides mechanical support and protection to the semiconductor layer, preventing cracks and foreign matter penetration while maintaining the intended current confinement geometry
2Productivity
If the oxidized layer aperture is made smaller to improve current intensity in the light emitting region, then luminous efficacy is improved, but energy consumption increases due to higher current density
Solution Approach 1:
The patent optimizes the aperture diameter of the oxidized layer as a key parameter to achieve the desired balance. By carefully selecting the aperture size, the current density is controlled to provide sufficient current intensity for high luminous efficacy while avoiding excessive current density that would lead to high energy consumption and potential damage
3Shape
If the aperture of the oxidized layer is reduced to improve light straightness, then beam quality is improved, but current flow intensity in the light emitting region decreases
Solution Approach 1:
The patent treats the aperture diameter as a critical parameter that must be optimized to balance light beam straightness and current flow intensity. The aperture size is carefully controlled to provide sufficient diffraction limitation for straight beam propagation while maintaining adequate current flow intensity in the light emitting region
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 device achieves low energy consumption, high reliability, improved light straightness, and enhanced luminous efficacy by intensifying current flow in the light emitting region and preventing semiconductor layer deterioration.
Implementation Method 1
a second mirror layer disposed on the first mirror layer, a cavity layer disposed between the first mirror layer and the second mirror layer and generating light
Implementation Method 2
The first mirror layer may include a plurality of first and second refractive index layers repeatedly stacked in sequence
Data Source
AI summary
A light emitting device including a first mirror layer, a second mirror layer disposed on the first mirror layer, a cavity layer disposed between the first mirror layer and the second mirror layer and configured to generate light, and a mesa exposing side surfaces of the second mirror layer and the cavity layer, in which the second mirror layer includes at least one oxidized layer forming an aperture through which light generated in the cavity layer is configured to pass, and lengths of the oxidized layer from edges of the oxidized layer to the aperture are in the range of 0.95 to 1.05 times a diameter of the aperture.