Semiconductor Laser Quantum Wire DBR Structure
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Solution Overview
Problem
Existing semiconductor lasers with a butt joint structure suffer from increased optical coupling loss and complex preparation processes, and the addition of impurities to the active layer leads to higher optical loss.
Innovation Solution
A semiconductor laser design that eliminates the butt joint structure by using first and second quantum wires with buried semiconductor regions to form distributed Bragg reflectors, where the first distributed Bragg reflector has higher reflectivity and a larger bandwidth than the second, allowing for single-mode operation without the need for a butt joint structure or additional HR coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a butt joint structure is used to optically couple the active layer region to the optical waveguide layer, then optical coupling is achieved, but optical coupling loss increases and the preparation process becomes complicated
Solution Approach 1:
The patent merges the active layer region and optical waveguide layer into a single continuous InGaAsP semiconductor layer, eliminating the butt joint interface between separate layers. This integration removes the optical coupling loss associated with interfaces while maintaining effective optical coupling through the unified structure.
Solution Approach 2:
The patent extracts and removes the problematic butt joint structure from the design. By eliminating the separate InGaAlAs active layer and its interface with the InGaAsP waveguide layer, the source of optical coupling loss is completely removed while the desired optical coupling function is maintained through the integrated layer.
2Reliability
If a butt joint structure with multiple semiconductor layers is used, then optical coupling is achieved, but the preparation process becomes complicated
Solution Approach 1:
The patent combines multiple semiconductor layers (InGaAlAs active layer and InGaAsP waveguide layer) into a single integrated InGaAsP layer, reducing the number of distinct layers and interfaces that need to be precisely aligned and joined, thereby simplifying the preparation process.
Solution Approach 2:
The single InGaAsP semiconductor layer serves multiple functions simultaneously: it acts as both the active layer region for light generation and the optical waveguide layer for light transmission, eliminating the need for separate specialized layers and their complex joining process.
3Adaptability or versatility
If impurity is added to the active region to control band-gap energy, then band-gap control is achieved, but optical loss of the active layer increases
Solution Approach 1:
The patent changes the compositional parameter of the semiconductor material from InGaAlAs to InGaAsP, adjusting the material composition to achieve the desired band-gap energy control without relying on impurity addition, thereby avoiding the associated optical loss.
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 design reduces optical coupling loss and simplifies the preparation process while achieving higher optical output and single-mode operation by utilizing quantum wire structures with alternating refractive indices to form Bragg reflectors, enhancing the semiconductor laser's performance.
Implementation Method 1
a first distributed Bragg reflector disposed on the first area and including the plurality of first quantum wires and the buried semiconductor regions disposed between the side faces of the first quantum wires; a second distributed Bragg reflector disposed on the second area and including the plurality of second quantum wires and the buried semiconductor regions disposed between the side faces of the second quantum wires
Data Source
AI summary
A semiconductor laser includes a first optical confinement layer, a plurality of first quantum wires and buried semiconductor regions disposed on a first area, a plurality of second quantum wires and buried semiconductor regions disposed on a second area, an active layer disposed on a third area, and a second optical confinement layer. The plurality of first quantum wires and the buried semiconductor regions constitute a first distributed Bragg reflector, and the plurality of second quantum wires and the buried semiconductor regions constitute a second distributed Bragg reflector. The third area is disposed between the first area and the second area. The buried semiconductor regions have a refractive index different from the average refractive index of the first quantum wires and the average refractive index of the second quantum wires. These distributed Bragg reflectors form a DBR laser having a cavity length defined by the length of the active layer.