Semiconductor Laser Cladding Structure for Low Optical Absorption
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Solution Overview
Problem
Optical absorption in the p-type cladding layer of semiconductor lasers, particularly in the eye-safe wavelength region, is a problem, and reducing its thickness to suppress absorption complicates optical confinement.
Innovation Solution
A semiconductor laser design with a p-type cladding layer thickness less than the n-type cladding layer, incorporating an n-type cladding layer to maintain optical confinement, and a p-type burying layer for heat dissipation, along with a reverse bias voltage to enhance pn junction potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the thickness of the p-type cladding layer is reduced to suppress optical absorption, then optical absorption is suppressed, but optical confinement becomes difficult
Solution Approach 1:
The cladding layer is segmented into multiple sections: a first cladding layer with thickness of 0.5-2.0 μm, a second cladding layer with thickness of 0.1-0.5 μm, and a third cladding layer with thickness of 0.5-2.0 μm. This segmentation allows each layer to perform specialized functions - the thinner middle layer reduces absorption while the thicker outer layers maintain optical confinement, resolving the contradiction between suppressing optical absorption and maintaining optical confinement.
2Loss of energy
If the thickness of the p-type cladding layer is reduced, then optical absorption is suppressed, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the thickness parameters of different cladding layers (first: 0.5-2.0 μm, second: 0.1-0.5 μm, third: 0.5-2.0 μm) and doping concentrations. This systematic parameter optimization achieves the dual goal of suppressing optical absorption through reduced p-type layer thickness while maintaining optical confinement through appropriate overall structure, without excessive 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
Suppresses optical absorption while maintaining optical confinement and improving heat dissipation, reducing leakage currents, and simplifying the laser configuration.
Implementation Method 1
optical absorption in the p-type cladding layer becomes a problem
Implementation Method 2
it is possible to secure the thickness of the entirety of the one cladding layer. According to this, appropriate optical confinement between the first cladding layer and the second cladding layer is enabled
Implementation Method 3
heat generated in the active layer is dissipated via the p-type burying layer
Data Source
AI summary
Provided is a semiconductor laser including: a semiconductor substrate; a semiconductor lamination portion laminated on a surface of the semiconductor substrate; and a first electrode and a second electrode. The semiconductor lamination portion includes an active layer, a first cladding layer located on the semiconductor substrate side with respect to the active layer, and a second cladding layer located on a side opposite to the semiconductor substrate with respect to the active layer, each of the first cladding layer and the second cladding layer includes an n-type cladding layer, one cladding layer of the first cladding layer and the second cladding layer further includes a p-type cladding layer located between the n-type cladding layer and the active layer.