Deep-Etched Waveguide Modulator with Non-Constant Width
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electro-optic waveguide modulators face challenges due to acousto-optic distortion, which causes resonance in the frequency response, making it difficult to identify and address, thereby impacting the modulator's performance.
Innovation Solution
The implementation of an electro-optic waveguide modulator with a deep-etched waveguide having a non-constant width, where the difference between the maximum and minimum widths satisfies a specific threshold, minimizes acousto-optic resonance by distributing its width over a larger frequency range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a constant width waveguide is used, then the manufacturing process is simple, but acousto-optic resonance occurs causing frequency response distortion
Solution Approach 1:
The waveguide width is made non-uniform along its length, with different sections having different widths. This local variation in geometry disrupts the formation of standing acoustic waves while maintaining effective optical confinement in each local region, thereby reducing acousto-optic resonance without completely redesigning the entire waveguide structure
Solution Approach 2:
The waveguide width parameter is deliberately varied along the propagation direction rather than kept constant. This parameter change transforms the uniform structure into a non-uniform one, which shifts and distributes acoustic resonances across a broader frequency range, reducing their impact on any single operating frequency
2Reliability
If the waveguide width varies significantly, then acousto-optic resonance is reduced, but manufacturing precision requirements increase
Solution Approach 1:
Rather than requiring extreme width variations, the patent applies a moderate width difference (e.g., 1-2 micrometers) along the waveguide length. This partial action is sufficient to disrupt acoustic resonance patterns while remaining within standard manufacturing tolerances for lithography and etching processes
Solution Approach 2:
The waveguide width transitions are designed with smooth, continuous curves rather than abrupt steps. This curvature in the width profile prevents sharp discontinuities that would be difficult to manufacture, while still achieving the necessary non-uniformity to suppress acoustic resonances
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 approach reduces the amplitude of acousto-optic resonance and distributes its frequency range, thereby minimizing its impact on the performance of the electro-optic waveguide modulator.
Implementation Method 1
This material strain can result in acoustic waves (e.g., that are generated by an exposed depletion field of the waveguide and then confined by sidewalls of the waveguide), often referred to as acousto-optic effect.
Implementation Method 2
applying an electric field to the waveguide (e.g., to enable electro-optic modulation of the waveguide) can cause a mechanical deformation of the material (e.g., as a result of a converse piezoelectric effect)
Data Source
AI summary
In some implementations, an electro-optic waveguide modulator includes a deep-etched waveguide. A first cladding is disposed on a top surface of the deep-etched waveguide. A second cladding is disposed on a bottom surface of the deep-etched waveguide. The deep-etched waveguide has a length that extends in a first direction and a width that extends in a second direction. The width of the deep-etched waveguide is non-constant along at least a portion of the length of the deep-etched waveguide. For example, a difference between a maximum width of the deep-etched waveguide and a minimum width of the deep-etched waveguide along at least the portion of the length of the deep-etched waveguide satisfies a width difference threshold that is equal to 10% of the maximum width.