Dual-Wavelength Semiconductor Laser Cladding Impurity Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor laser devices face challenges in achieving compactness, low noise, and wide temperature operation stability, particularly when high impurity concentrations in the cladding layer lead to unstable self-oscillation and reliability issues.
Innovation Solution
A semiconductor laser device with a double hetero structure for each wavelength, featuring different impurity concentrations in the second-conductivity type cladding layers to stabilize self-oscillation, suppress current spread, and maintain temperature reliability, is developed. This structure includes AlGaInP cladding layers and active layers like GaAs and GaInP, optimizing impurity concentrations to ensure multimode oscillation and temperature stability across a wide range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high impurity concentration is used in the cladding layer to improve temperature characteristics, then temperature stability is improved, but self-oscillation stability deteriorates and reliability decreases
Solution Approach 1:
The patent applies different impurity concentrations to different cladding layers (first cladding layer vs. second cladding layer) to achieve different local properties. The first cladding layer has higher impurity concentration for temperature stability, while the second cladding layer has lower impurity concentration to maintain self-oscillation stability, thus resolving the contradiction through spatial differentiation of material properties.
2Temperature
If high impurity concentration is used in the cladding layer to improve temperature characteristics, then temperature stability is improved, but device reliability deteriorates
Solution Approach 1:
The patent uses a dual-cladding layer structure where the first cladding layer (closer to the active layer) has lower impurity concentration to ensure device reliability and self-oscillation stability, while the second cladding layer (outer layer) has higher impurity concentration to provide temperature stability. This local differentiation resolves the contradiction between temperature characteristics and device reliability.
3Volume of moving object
If monolithic semiconductor laser is used to integrate multiple lasers on one substrate to achieve compactness, then device compactness is improved, but optical component sharing increases complexity
Solution Approach 1:
The patent integrates multiple semiconductor lasers with different wavelengths (red laser for DVD and infrared laser for CD) onto a single semiconductor substrate, forming a monolithic structure. This merging of multiple laser functions into one device achieves compactness by eliminating the need for separate laser modules and their associated optical components, while the shared optical path further reduces overall system complexity.
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 device achieves stable multimode oscillation, improved temperature characteristics, and reliability in a wide temperature range without the need for high-frequency circuits, making it suitable for optical disk systems.
Implementation Method 1
it is necessary to form a saturable absorber whose absorption region for a laser beam formed in a waveguide is excited by the laser beam itself so as to reduce the light absorption and to ultimately become transparent
Implementation Method 2
the carriers are abruptly lost, and ultimately the number of carriers becomes so small that the laser oscillation is halted
Data Source
AI summary
In a monolithic dual wavelength laser device in which an infrared laser part 100 and a red laser part 130 are built on one n-type GaAs substrate 101, a p-type first cladding layer 105 of the infrared laser part 100 and a p-type first cladding layer 135 of the red laser part 130 are made of the same material and have different impurity concentrations.