GaN Semiconductor Laser Cavity Structure for Short Resonant Lengths
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Solution Overview
Problem
Semiconductor lasers with GaN-based compounds face challenges in achieving stable laser oscillation at short resonant lengths due to high threading dislocation densities and low optical gain, which affects their efficiency and output.
Innovation Solution
A semiconductor laser body with a base semiconductor part and a compound semiconductor part containing GaN-based semiconductors, where the base semiconductor part has regions with varying threading dislocation densities and the compound semiconductor part includes optical resonators with m-plane or c-plane resonant end surfaces, optimized for low dislocation and high optical reflectance, allowing for stable laser oscillation even at short resonant lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the resonant length is shortened to improve device compactness, then the device size is reduced, but stable laser oscillation becomes difficult to achieve due to high threading dislocation densities and low optical gain
Solution Approach 1:
The patent applies local quality by creating a base semiconductor part with spatially varying threading dislocation density. Specifically, the region beneath the compound semiconductor part has a lower threading dislocation density compared to other regions of the base semiconductor part. This localized improvement in crystal quality beneath the active region enables stable laser oscillation at short resonant lengths by reducing dislocation-related non-radiative recombination, while maintaining the compact device size.
2Ease of manufacture
If conventional base semiconductor parts with high threading dislocation densities are used, then the manufacturing process is simpler, but reflection loss increases and light emission efficiency decreases
Solution Approach 1:
The patent applies parameter changes by modifying the threading dislocation density distribution in the base semiconductor part. Instead of using a uniform high-density structure, the invention creates a heterogeneous density profile where the region beneath the compound semiconductor part has reduced threading dislocation density. This parameter modification reduces non-radiative recombination centers, thereby decreasing reflection loss and improving light emission efficiency while maintaining manufacturing feasibility through controlled growth processes.
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 design enables stable laser oscillation and high efficiency at short resonant lengths, reducing reflection loss and enhancing light emission efficiency by minimizing dislocation effects and optimizing resonant end surface planarity and reflectance.
Implementation Method 1
at least one of the pair of resonant end surfaces is an m-plane or a c-plane of the compound semiconductor part
Data Source
AI summary
A semiconductor laser body includes a base semiconductor part and a compound semiconductor part positioned on the base semiconductor part and containing a GaN-based semiconductor. The base semiconductor part includes a first portion and a second portion having a lower density of threading dislocation extending in a thickness direction than the first portion, the compound semiconductor part includes an optical resonator including a pair of resonant end surfaces, at least one of the pair of resonant end surfaces is an m-plane or a c-plane of the compound semiconductor part, and a resonant length, which is a distance between the pair of resonant end surfaces, is equal to or less than 200 [μm].