Surface-Emitting Laser Oxidation Structure for Isotropic Current Confinement
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Solution Overview
Problem
Conventional semiconductor lasers face challenges in controlling the current confinement diameter due to variations in oxidation length, particularly when the oxidation confinement layer is thickened on specific crystal orientations, making isotropic selective oxidation difficult.
Innovation Solution
A surface emitting laser design with a semiconductor layer having a forward or reverse tapered longitudinal cross section and an oxidation confinement layer with an oxidation adjustment structure, including thin film portions and route-around features, to prevent thickening on specific crystal planes and ensure isotropic oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional semiconductor laser with step pattern is used, then selective oxidation can be performed, but the oxidation confinement layer thickens on {111} A planes causing non-isotropic oxidation
Solution Approach 1:
The patent applies asymmetry by designing the step pattern with specific crystallographic orientations that avoid exposing {111} A planes. By selecting orientations such as <100> or <110> for the step boundaries, the oxidation process achieves isotropic characteristics across all directions, eliminating the directional thickening problem inherent in conventional designs.
Solution Approach 2:
The patent changes the crystallographic orientation parameters of the step pattern to prevent {111} A plane exposure. By adjusting the orientation angles and selecting specific low-index planes for the step boundaries, the oxidation behavior is modified to achieve uniform thickness across all radial directions, transforming the oxidation process from anisotropic to isotropic.
2Reliability
If oxidation confinement layer is formed on step boundary with {111} A plane, then current confinement can be achieved, but oxidation length varies making diameter control difficult
Solution Approach 1:
The patent eliminates the asymmetric thickening effect by avoiding {111} A plane exposure in the step pattern design. This ensures that oxidation proceeds uniformly in all radial directions, allowing precise control of the oxidation confinement diameter while maintaining reliable current confinement through the uniformly thick oxidation barrier.
Solution Approach 2:
The patent performs preliminary design of the step pattern geometry and crystallographic orientation before the oxidation process. By pre-configuring the step boundaries to avoid problematic orientations, the oxidation process naturally produces uniform thickness without requiring post-processing adjustment, enabling precise diameter control from the outset.
3Shape
If step pattern has slope with perpendicular plane to crystal orientation, then {111} A plane appears on surface, but oxidation confinement layer thickens making isotropic oxidation difficult
Solution Approach 1:
The patent redesigns the step pattern to eliminate symmetric exposure of {111} A planes by selecting specific asymmetric crystallographic orientations for the step boundaries. This geometric modification ensures that no radial direction exposes the problematic plane, achieving uniform oxidation thickness while maintaining the necessary step pattern shape for device functionality.
Solution Approach 2:
The patent modifies the crystallographic orientation parameters of the step pattern surfaces to prevent {111} A plane formation. By changing the orientation angles to specific values that avoid the problematic plane exposure, the oxidation process achieves uniform thickness across all directions while maintaining appropriate step pattern geometry for current confinement.
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 isotropic selective oxidation, maintaining consistent current confinement diameter and improving laser characteristics by preventing thickening on {111} A planes, thereby enhancing the feasibility of isotropic selective oxidation.
Implementation Method 1
an oxidation confinement layer disposed between the second multilayer film reflector and the active layer and having a non-oxidized region and an oxidized region
Data Source
AI summary
A surface emitting laser having an isotropically selectively oxidized oxidation confinement layer is provided.The surface emitting laser according to the present technology includes: a first multilayer film reflector; a second multilayer film reflector; an active layer disposed between the first and second multilayer film reflectors; and an oxidation confinement layer disposed between the second multilayer film reflector and the resonator and having a non-oxidized region and an oxidized region, in which the oxidation confinement layer includes an oxidation adjustment structure. According to the surface emitting laser according to the present technology, it is possible to provide a surface emitting laser having an isotropically selectively oxidized oxidation confinement layer.