Ridge Stripe Laser Structure for Uniform Carrier Density
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Solution Overview
Problem
Existing optical semiconductor devices face complexity in operational control and manufacturing due to the need for multiple current sources to manage current ratios and precise dopant density distribution, leading to unstable single-mode operation and manufacturing difficulties.
Innovation Solution
The optical semiconductor device features a ridge stripe structure with varying current narrowing windows and diffraction gratings, allowing for controlled resistance distribution by adjusting the shape and thickness of burying layers, which minimizes carrier density imbalance and stabilizes single-mode operation without requiring complex operational control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If multiple current sources are used to control current ratios in divided electrodes, then carrier density uniformity is improved, but device complexity and operational control complexity increase
Solution Approach 1:
The invention changes the physical structure of the cladding layer by introducing a resistivity distribution along the light traveling direction. This structural parameter change allows the device to self-regulate carrier density distribution without requiring multiple current sources or complex control systems, thus improving carrier density uniformity while avoiding increased device complexity
Solution Approach 2:
The resistivity distribution in the cladding layer creates a self-regulating mechanism where the device automatically adjusts carrier density distribution through its inherent structural properties. This eliminates the need for external control systems or multiple current sources, allowing the device to achieve uniform carrier density through self-service
2Stability of the object's composition
If dopant density distribution is precisely controlled to vary resistivity inside the element, then carrier density uniformity is improved, but manufacturing difficulty increases
Solution Approach 1:
The invention introduces a resistivity distribution parameter in the cladding layer that can be controlled during standard manufacturing processes. By adjusting this parameter, the device achieves uniform carrier density distribution without requiring precise control of dopant density, thereby improving manufacturability while maintaining the desired electrical characteristics
Solution Approach 2:
The resistivity distribution is implemented as a local property of the cladding layer that varies along the light traveling direction. This localized quality change allows the device to achieve uniform carrier density without requiring precise control of dopant distribution throughout the entire structure, simplifying the manufacturing process
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 enables stable operation of the optical semiconductor device by uniformly distributing carrier density and reducing longitudinal hole burning, facilitating accurate manufacturing and eliminating the need for intricate operational control.
Implementation Method 1
a diffraction grating... only a specific wavelength causes resonance in the resonator
Implementation Method 2
light is reflected off the end face or the diffraction grating, to thereby propagate again in the waveguide
Implementation Method 3
holes and electrons are injected from the p-type cladding layer-side and the n-type cladding layer-side, respectively, and are recombined in the active layer to thereby emit light
Implementation Method 4
a λ/4 phase shifter is placed at an intermediate portion in a light traveling direction
Data Source
AI summary
There is provided a configuration which includes: a burying layer which has a current narrowing window where portions protruding onto a top part of a ridge stripe are opposed to each other with an interval therebetween narrower than a width of the top part; and a diffraction grating in which a λ/4 phase shifter is placed at an intermediate portion in a light traveling direction; wherein a sectional shape of the current narrowing window varies depending on a position in the light traveling direction so that, at a region where the λ/4 phase shifter is placed, a resistance of a current path from a second cladding layer to a first cladding layer through the current narrowing window is minimum.