Thin-Film Lithium Niobate Modulator on Silicon Photonics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing silicon-based electro-optical modulators are unable to meet the requirements for high-speed connectivity beyond 128 GBd, particularly in terms of modulation speed, efficiency, and optical losses.
Innovation Solution
The development of an electro-optical modulator using a thin-film lithium niobate (TFLN) waveguide on a silicon photonic circuit, with a differential electrical drive, allowing for efficient polarization rotation of optical signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If silicon-based electro-optical modulators are used, then manufacturing compatibility is improved, but modulation speed and efficiency deteriorate at speeds above 128 GBd
Solution Approach 1:
The patent employs a hybrid structure combining silicon photonics waveguides with thin-film lithium niobate (TFLN) electro-optical material. The silicon substrate provides manufacturing compatibility and waveguide functionality, while the TFLN layer enables high-speed modulation beyond 128 GBd with improved efficiency, thus resolving the contradiction between ease of manufacture and modulation speed.
2Device complexity
If silicon-based electro-optical modulators are used, then device integration is improved, but efficiency and optical losses worsen
Solution Approach 1:
The composite structure of silicon waveguides integrated with TFLN thin film achieves both high device integration and low optical losses. The TFLN material exhibits superior electro-optical properties with lower loss characteristics, while maintaining compatibility with silicon photonic platforms, thus resolving the trade-off between integration and optical efficiency.
3Speed
If modulation speed is increased beyond 128 GBd, then connectivity requirements are met, but efficiency and optical losses worsen
Solution Approach 1:
The patent changes the material parameter from pure silicon to thin-film lithium niobate, which fundamentally alters the electro-optical response characteristics. This material parameter change enables simultaneous achievement of high modulation speeds beyond 128 GBd and improved switching efficiency with reduced optical losses, resolving the contradiction between speed and efficiency.
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 solution achieves high-speed modulation beyond 200 GBd with improved efficiency and reduced optical losses, while also reducing the size of the modulators.
Implementation Method 1
electro-optical thin film disposed on the substrate... apply a differential electrical signal between the first and second electrodes to modulate a polarization of the optical signal
Data Source
AI summary
An electro-optical modulator includes a substrate and an optical waveguide including an electro-optical thin film disposed on the substrate. The optical waveguide has an input end coupled to receive an optical signal and an output end opposite the input end. First and second electrodes are disposed on the substrate along opposite sides of the waveguide. A differential driver has first and second differential outputs coupled to apply a differential electrical signal between the first and second electrodes to modulate a polarization of the optical signal propagating in the waveguide.