Surface Emission Laser Impurity Area Design
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Solution Overview
Problem
Existing surface emission lasers face challenges in efficiently injecting current to the active layer while maintaining the crystallinity of layers stacked above the contact area, as high impurity doping in the contact area leads to crystallinity deterioration and inefficient current injection.
Innovation Solution
A surface emission laser design featuring a mesa structure with a first and second multilayer film reflector, an active layer, and an impurity area extending from the contact area to the side wall section of the mesa, allowing for efficient current injection with a lower impurity concentration and reduced crystallinity deterioration, along with a contact layer and current constriction layer for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high impurity doping is applied in the contact area to improve current injection efficiency, then current injection efficiency is improved, but crystallinity of layers stacked above the contact area deteriorates
Solution Approach 1:
The patent applies different impurity concentrations to different spatial regions: high impurity concentration is localized to the contact area and side wall section to improve current injection, while the active layer and layers above maintain low impurity concentration to preserve crystallinity. This spatial differentiation of impurity distribution resolves the contradiction between current injection efficiency and crystallinity maintenance.
Solution Approach 2:
The structure is segmented into distinct functional zones with different impurity characteristics: the contact area with high impurity concentration for current injection, the side wall section with moderate impurity concentration for current confinement, and the active layer with low impurity concentration for maintaining high crystallinity and optical performance. This segmentation allows each zone to optimize its function without compromising other zones.
2Productivity
If the impurity area is extended to the side wall section of the mesa structure, then current injection efficiency is improved, but the complexity of the manufacturing process increases
Solution Approach 1:
The insulating film is formed in advance covering both the mesa structure and the area to be doped, including the side wall section. This preliminary action defines the doping region before impurity introduction, enabling precise control of impurity distribution without requiring complex post-doping processing steps. The side wall section is prepared to receive impurities through the insulating film, simplifying the overall manufacturing process.
Solution Approach 2:
The insulating film serves as an intermediary that enables controlled impurity diffusion to the side wall section. By forming the insulating film patterned to expose specific areas, the patent mediates the doping process to achieve precise spatial control of impurity concentration without requiring complex direct doping techniques. This intermediary approach simplifies the manufacturing process while achieving the desired impurity distribution.
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 enables efficient current injection to the active layer while suppressing crystallinity deterioration of layers above the contact area, improving the laser's efficiency and optical output power, and reducing the size and resistance of the current path.
Implementation Method 1
an impurity area is provided over a contact area that is adjacent to a mesa structure and contacts an electrode, and over a side wall section of a portion of the mesa structure that the portion includes the first multilayer film reflector
Data Source
AI summary
There are provided a surface emission laser 10, a surface emission laser array in which the surface emission laser 10 is arrayed two-dimensionally, and a surface emission laser manufacturing method that enable efficient injection of a current to an active layer 200b, while suppressing deterioration of the crystallinity of layers stacked above a contact area.The present technology provides a surface emission laser 10 including a substrate 100, and a mesa structure 200 formed on the substrate 100, in which the mesa structure 200 includes at least a part of a first multilayer film reflector 200a stacked on the substrate 100, an active layer 200b stacked on the first multilayer film reflector 200a, and a second multilayer film reflector 200c stacked on the active layer 200b, and an impurity area 800 is provided over a contact area CA that is adjacent to the mesa structure 200, and contacts an electrode 600, and a side wall section of a portion of the mesa structure 200 which portion includes the first multilayer film reflector 200a.