VCSEL Drop-Shaped Oxide Aperture for Degenerate Mode Suppression
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Solution Overview
Problem
The circular oxide aperture in existing VCSELs leads to rotational symmetry, causing multiple degenerate modes at the same frequency point, which increases relative intensity noise (RIN) and root mean square spectral width, resulting in higher bit error ratios and degraded communication quality.
Innovation Solution
A high-speed vertical cavity surface emitting laser with a drop-shaped oxide aperture in the oxide-confined layer, which breaks rotational symmetry, reducing the generation of multiple degenerate modes and improving the consistency of RIN and root mean square spectral width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a circular oxide aperture is used in the VCSEL, then the manufacturing process is simple and the structure is symmetric, but multiple degenerate modes occur at the same frequency point causing increased mode partition noise and relative intensity noise
Solution Approach 1:
The patent applies asymmetry by changing the oxide aperture shape from circular to drop-shaped. This asymmetric geometry breaks the rotational symmetry that causes degenerate modes in circular apertures. The drop-shaped aperture has a specific aspect ratio (length-to-width ratio between 1.1 and 2.0) that eliminates mode partition noise while maintaining single-mode operation, thereby improving communication quality without significantly complicating the manufacturing process
2Stability of the object's composition
If a circular oxide aperture is used in the VCSEL, then the structure has high rotational symmetry, but the relative intensity noise and root mean square spectral width increase due to degenerate mode competition
Solution Approach 1:
The patent applies asymmetry by changing the oxide aperture shape from circular to drop-shaped. This asymmetric geometry breaks the rotational symmetry that causes degenerate modes in circular apertures. The drop-shaped aperture has a specific aspect ratio (length-to-width ratio between 1.1 and 2.0) that eliminates mode partition noise, thereby reducing relative intensity noise and improving signal quality
3Reliability
If a drop-shaped oxide aperture is used in the VCSEL, then mode partition noise is reduced and communication quality is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies parameter changes by optimizing the aspect ratio of the drop-shaped aperture (length-to-width ratio between 1.1 and 2.0). This specific parameter range achieves the best balance between eliminating mode partition noise and maintaining manufacturability. The controlled parameter specification allows for standardized manufacturing processes while achieving superior communication quality
Data Source
AI summary
The present disclosure provides a high-speed vertical cavity surface emitting laser, an optoelectronic device with the same, and a manufacturing method thereof. The high-speed vertical cavity surface emitting laser includes a substrate layer, a first electrode layer, a first reflector layer, an active layer, an oxide-confined layer, a second reflector layer and a second electrode layer, wherein the first electrode layer is an N-type electrode layer and the second electrode layer is a P-type electrode layer. The oxidation aperture in the oxide-confined layer is drop-shaped.