AlGaInP Semiconductor Laser Stripe Structure for High-Temperature Stability
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Solution Overview
Problem
Wide stripe semiconductor laser devices with AlGaInP cladding layers face challenges in achieving high temperature stability, reducing operating voltage, and improving wall-plug efficiency due to high electrical resistivity, leading to increased power loss and shortened device lifespan.
Innovation Solution
A semiconductor laser device structure with a first n-type cladding layer of Alx1Ga1-x1As and a second n-type cladding layer of (Alx2Ga1-x2)1-y2Iny2P, along with a p-type cladding layer of (Alx3Ga1-x3)1-y3Iny3P, where the refractive index of the first n-type cladding layer is less than or equal to the second n-type cladding layer, and the stripe width is 10 μm or more, to optimize optical confinement and reduce resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an AlGaInP cladding layer is used to improve high-temperature characteristics, then high-temperature stability is improved, but electrical resistivity increases causing higher power loss
Solution Approach 1:
The n-type cladding layer is divided into two distinct layers: a first n-type cladding layer (AlGaAs) with low electrical resistivity and a second n-type cladding layer (AlGaInP) with high band gap. This segmentation allows each layer to fulfill different functions - the first layer provides low resistance current transport while the second layer provides high-temperature carrier confinement through its large band gap difference with the active layer.
Solution Approach 2:
Different regions of the cladding structure are assigned different material properties optimized for their specific functions. The first cladding layer uses AlGaAs material with low resistivity for efficient current conduction, while the second cladding layer uses AlGaInP material with high band gap for superior carrier confinement at high temperatures. This local optimization of material properties resolves the contradiction between low resistance and high-temperature stability.
2Power
If a large current is injected to achieve high optical output, then optical output is improved, but wall-plug efficiency declines due to heat generation
Solution Approach 1:
The invention converts the potentially harmful effect of high current injection into a benefit by using the large band gap of AlGaInP to confine carriers more effectively. This prevents carrier overflow and non-radiative recombination that would otherwise convert electrical energy into wasted heat, thereby maintaining higher wall-plug efficiency even during high-power operation.
Solution Approach 2:
The cladding structure employs a composite of two different semiconductor materials (AlGaAs and AlGaInP) with complementary properties. The AlGaAs provides low resistivity for efficient current injection, while the AlGaInP provides high band gap for effective carrier confinement. This composite structure enables high optical output with improved wall-plug efficiency by minimizing energy loss to heat.
3Power
If the stripe width is increased to supply large current, then current capacity is improved, but optical confinement becomes more difficult
Solution Approach 1:
The invention changes the critical parameter of band gap difference by introducing AlGaInP material in the second cladding layer. This material provides a significantly larger band gap difference with the GaAs active layer compared to conventional AlGaAs cladding. The enhanced band gap difference strengthens the potential well effect, improving optical confinement even in wide stripe structures where current capacity requirements demand larger cross-sectional areas.
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 high-temperature stability, reduces operating voltage, and improves wall-plug efficiency by controlling carrier density and refractive index differences, resulting in a more efficient and longer-lasting semiconductor laser device.
Implementation Method 1
the refractive index with respect to the laser oscillation wavelength of the first n-type cladding layer is less than or equal to the refractive index with respect to the laser oscillation wavelength of the second n-type cladding layer
Implementation Method 2
a semiconductor laser device that emits multi-mode laser light
Implementation Method 3
Transform Electrical Energy to Optical Energy
Implementation Method 4
a large band gap difference between the active layer and the cladding layer can be obtained, and carrier overflow can be suppressed
Data Source
AI summary
In a semiconductor laser device, a n-type cladding layer, a multi-quantum well active layer, and a p-type cladding layer are sequentially laminated on an n-type substrate, and a stripe structure is provided on this semiconductor laminated section. The n-type cladding layer has a first n-type cladding layer configured of Alx1Ga1-x1As (0.4<x1≤1), and a second n-type cladding layer configured of (Alx2Ga1-x2)1-y2Iny2P (0≤x2≤1, 0.45≤y2≤0.55). The p-type cladding layer is configured of (Alx3Ga1-x3)1-y3Iny3P (0≤x3≤1, 0.45≤y3≤0.55). The width of the stripe structure is 10 μm or more, and the refractive index with respect to the laser oscillation wavelength of the first n-type cladding layer is less than or equal to the refractive index with respect to the laser oscillation wavelength of the second n-type cladding layer.