Hydrogen Gradient in PBH Laser Cladding for High-Temperature Stability
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Solution Overview
Problem
Conventional PBH lasers experience an increase in oscillation threshold current and a decrease in external differential quantum efficiency when operated at high temperatures and high optical outputs, leading to a shorter lifetime due to increased operating current.
Innovation Solution
The optical semiconductor device features a higher hydrogen concentration in the p-type cladding layer compared to the p-type blocking layer, which mitigates hydrogen migration and maintains carrier concentration, thereby preventing an increase in oscillation threshold current and maintaining external differential quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional PBH laser is operated at high temperature and high optical output, then the optical output is maintained, but the oscillation threshold current increases and external differential quantum efficiency decreases
Solution Approach 1:
The patent applies local quality by creating a hydrogen concentration gradient within the p-type cladding layer. The hydrogen concentration is higher near the interface with the active layer and decreases toward the outer region. This non-uniform distribution locally enhances carrier concentration at the critical interface region, preventing threshold current increase during high-power operation without affecting other regions negatively.
Solution Approach 2:
The patent changes the hydrogen concentration parameter within the p-type cladding layer to resolve the contradiction. By introducing hydrogen at controlled concentrations during epitaxial growth, the carrier concentration is enhanced locally, which stabilizes the oscillation threshold current during high-temperature, high-output operation while maintaining the required optical output power.
2Power
If a conventional PBH laser is operated at high temperature and high optical output, then the optical output is maintained, but external differential quantum efficiency decreases
Solution Approach 1:
The patent applies local quality by creating a hydrogen concentration gradient within the p-type cladding layer. The hydrogen concentration is higher near the interface with the active layer and decreases toward the outer region. This non-uniform distribution locally enhances carrier concentration at the critical interface region, preventing threshold current increase during high-power operation without affecting other regions negatively.
Solution Approach 2:
The patent changes the hydrogen concentration parameter within the p-type cladding layer to resolve the contradiction. By introducing hydrogen at controlled concentrations during epitaxial growth, the carrier concentration is enhanced locally, which stabilizes the oscillation threshold current during high-temperature, high-output operation while maintaining the required optical output power.
3Duration of action of stationary object
If a conventional PBH laser is operated continuously at high temperature, then continuous operation is achieved, but the operating current increases and lifetime decreases
Solution Approach 1:
The patent applies preliminary action by introducing hydrogen into the p-type cladding layer during the epitaxial growth process, before the device enters operation. This preliminary hydrogen incorporation establishes a favorable hydrogen concentration gradient that proactively prevents carrier concentration degradation during subsequent high-temperature continuous operation, thereby extending device lifetime while maintaining continuous operation capability.
Solution Approach 2:
The patent changes the hydrogen concentration parameter within the p-type cladding layer to resolve the contradiction. By introducing hydrogen at controlled concentrations during epitaxial growth, the carrier concentration is enhanced locally, which stabilizes the oscillation threshold current during high-temperature, high-output operation while maintaining the required optical output power.
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 configuration enhances the reliability of the semiconductor laser by preventing an increase in oscillation threshold current and maintaining external differential quantum efficiency, even under high-temperature and high-output conditions, significantly extending the device's operational lifespan.
Implementation Method 1
which mitigates hydrogen migration and maintains carrier concentration
Data Source
AI summary
The reliability of a buried hetero-structure semiconductor laser is improved by preventing an increase in oscillation threshold current and a decrease in external differential quantum efficiency in cases where the semiconductor laser is energized continuously under conditions of high temperature and high optical output. An optical semiconductor laser has an optical waveguide structure comprising an n-type cladding layer, an active layer and p-type cladding layers, and a current narrowing/blocking structure comprising a p-type blocking layer and an n-type blocking layer, wherein concentration of hydrogen contained in the p-type cladding layers is higher than concentration of hydrogen contained in the p-type blocking layer.