Optical Semiconductor Device With InGaAs Intermediate Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical semiconductor devices with AlGaInAs-based multiple quantum well active layers suffer significant degradation when subjected to continuous current injection, leading to a substantial decrease in optical output, particularly in high-temperature applications.
Innovation Solution
Incorporating InGaAs-based intermediate layers between the AlGaInAs-based optical guide layers and InP cladding layers to prevent contact and reduce strain, thereby suppressing degradation by continuous current injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If AlGaInAs-based multiple quantum well active layer is used, then high-speed operation and superior band structure are achieved, but significant degradation occurs under continuous current injection leading to substantial decrease in optical output
Solution Approach 1:
An InGaAs-based intermediate layer is introduced between the AlGaInAs optical guide layer and the InP cladding layer. This intermediate layer acts as a mediator that prevents direct contact between the Al-containing and P-containing layers, thereby reducing strain and preventing crystal defects that cause degradation under continuous current injection, while maintaining the high-speed operation characteristics of the AlGaInAs active layer.
2Adaptability or versatility
If AlGaInAs-based optical guide layers are used with InP cladding layers, then superior band structure is achieved, but strain and crystal defects occur leading to degradation under continuous current injection
Solution Approach 1:
The InGaAs intermediate layer serves as a buffer between the AlGaInAs optical guide layer and the InP cladding layer, preventing direct interaction between Al and P atoms that would cause strain and crystal defects. This maintains the superior band structure while ensuring crystal structure stability under continuous operation.
Solution Approach 2:
The intermediate layer is specifically positioned only where the AlGaInAs layer contacts the InP cladding layer, providing localized strain relief and defect prevention at the critical interface, while maintaining the overall quality of the band structure throughout the device.
3Use of energy by moving object
If conventional buried heterostructure is used, then driving current is reduced and speedup is anticipated, but degradation by continuous current injection is significant
Solution Approach 1:
The InGaAs intermediate layer is integrated into the buried heterostructure configuration, maintaining the low driving current characteristics while preventing the strain-induced degradation that occurs in conventional designs. The intermediate layer protects the crystal structure without interfering with the current blocking and confinement functions of the buried heterostructure.
Data Source
AI summary
An optical semiconductor device includes an active layer, a first semiconductor layer formed above the active layer and made from a semiconductor material containing Al, a second semiconductor layer formed above the first semiconductor layer and made from a semiconductor material which does not contain any one of Al and P and whose band gap is greater than that of the active layer, and a third semiconductor layer formed above the second semiconductor layer and made from a semiconductor material which does not contain Al but contains P. The second semiconductor layer is formed such that the first semiconductor layer and the third semiconductor layer do not contact with each other.