VCSEL Wedge-Shaped Oxide Aperture for Lower Scattering Loss
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Solution Overview
Problem
The existing vertical cavity surface emitting lasers (VCSELs) suffer from increased photon scattering loss and reduced modulation bandwidth due to a thick circular arc oxide aperture structure.
Innovation Solution
A VCSEL design featuring a wedge-shaped oxide aperture with a thinner center and thicker outer sides, achieved by varying the aluminum composition in the AlxGa1-xAs oxide layer, which reduces photon scattering loss and parasitic capacitance while increasing modulation bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a thick circular arc oxide aperture structure is used, then the manufacturing process is simplified, but the photon scattering loss increases and modulation bandwidth decreases
Solution Approach 1:
The patent applies asymmetry by transitioning from a symmetric thick circular arc oxide aperture to an asymmetric wedge-shaped oxide aperture structure. The wedge shape creates different thickness profiles (thinner at center, thicker at edges) that asymmetrically manage photon paths, reducing scattering loss while maintaining manufacturing feasibility through controlled oxidation processes.
Solution Approach 2:
The patent implements local quality by creating spatially varying oxide thickness within the oxide aperture layer. The wedge-shaped structure provides different local thickness characteristics - thinner regions at the center for reduced scattering and thicker regions at the edges for maintained confinement - allowing each local region to optimize its function for the overall performance improvement.
2Device complexity
If a thick circular arc oxide aperture structure is used, then the device structure is simplified, but the modulation bandwidth is reduced
Solution Approach 1:
The asymmetric wedge-shaped oxide aperture structure replaces the symmetric circular arc design, creating non-uniform electrical and optical field distributions that reduce parasitic capacitance. This asymmetry in the oxide thickness profile enables faster modulation response by optimizing the capacitive coupling characteristics between laser layers.
Solution Approach 2:
The patent changes the geometric parameters of the oxide aperture from a uniform thick circular arc to a wedge-shaped profile with varying thickness. This parameter change in the oxide aperture geometry directly impacts the electrical capacitance and optical confinement properties, enabling improved modulation bandwidth while maintaining structural simplicity.
3Reliability
If the oxide layer thickness is increased, then the oxide aperture confinement is improved, but the photon scattering loss increases
Solution Approach 1:
The wedge-shaped oxide aperture structure applies local quality by providing different oxide thicknesses at different radial positions. The thinner central region minimizes photon scattering loss where the optical mode is concentrated, while the thicker peripheral regions maintain effective current and optical confinement at the edges, resolving the contradiction between confinement and scattering 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
The wedge-shaped oxide aperture structure effectively reduces photon scattering loss and increases the modulation bandwidth of the laser, enhancing its performance in applications such as optical communications and LiDAR.
Implementation Method 1
the oxide layer is obtained by oxidizing AlxGa1-xAs in which the content of an aluminum composition is gradually varied
Data Source
AI summary
The present disclosure provides a vertical cavity surface emitting laser, an electronic device with the same, and a manufacturing method for the same. The vertical cavity surface emitting laser includes a substrate layer, a first electrode layer, a first reflector layer, an active layer, an oxide layer, a second reflector layer, a second electrode layer, and a passivation layer, wherein the oxide layer includes a wedge-shaped structure on which an oxide aperture is formed, and the thickness of the center of the wedge-shaped structure is smaller than the thickness of its outer sides. The vertical cavity surface emitting laser provided by the present disclosure can play roles in reducing the photon scattering loss, reducing the parasitic capacitance, and increasing the modulation bandwidth of the laser.