Multi-Semiconductor Slab Electro-Optic Modulator Design
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Solution Overview
Problem
Current electro-optic modulators manufactured in CMOS compatible platforms have response speed limitations due to the geometry of current injection into optical waveguides, which restricts their performance.
Innovation Solution
A multi-semiconductor slab design is introduced, where current is injected vertically into a ridge-shaped semiconductor optical core, decoupling optical confinement and response speed, allowing for the creation of highly confining waveguides with fast response times and low optical loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If current is injected laterally into the optical waveguide using a single semiconductor slab design, then the device structure is simple and easy to manufacture, but the response speed is limited
Solution Approach 1:
The single semiconductor slab is divided into multiple semiconductor slabs (first semiconductor slab and second semiconductor slab) positioned at different heights. This segmentation allows independent optimization of each slab's function: the first slab provides optical confinement while the second slab enables fast response through vertical current injection, resolving the contradiction between structural simplicity and response speed.
Solution Approach 2:
The invention transitions from lateral current injection in a single plane to vertical current injection across multiple height levels. By stacking semiconductor slabs at different heights and injecting current vertically through the ridge-shaped core, the device achieves faster response speed while maintaining manufacturing compatibility through a systematic structural extension.
2Loss of energy
If optical confinement is increased in the waveguide, then optical loss increases due to overlap with ohmic contacts, but optical confinement is needed for efficient modulation
Solution Approach 1:
The optical waveguide structure is segmented into multiple semiconductor slabs at different heights, with the first slab providing optical confinement and the second slab positioned to minimize overlap with ohmic contacts. This vertical segmentation allows strong optical confinement where needed while reducing parasitic losses in the contact regions.
Solution Approach 2:
The invention moves the optical confinement function to a different vertical dimension by positioning the first semiconductor slab at a lower height than the second slab. This vertical separation allows the optical mode to be confined effectively in the first slab while the second slab handles current injection with minimal optical loss, decoupling the two functions spatially.
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 enables the optimization of electrical response speed and optical confinement independently, resulting in electro-optic modulators with faster response times and reduced optical losses compared to conventional devices.
Implementation Method 1
electro-optic modulator
Data Source
AI summary
In one embodiment, the apparatus includes a substrate having a surface and an optical waveguide having a ridge-shaped semiconductor optical core, the ridge-shaped semiconductor optical core being located over the surface. The apparatus may further include a first semiconductor slab being in contact with a first portion of the ridge-shaped semiconductor optical core, and a second semiconductor slab being in contact with a second portion of the ridge-shaped semiconductor optical core, the second semiconductor slab being farther from the surface than the first semiconductor slab.