Optical Waveguide Element Asymmetric Turnaround Design
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Solution Overview
Problem
In high-speed optical fiber communication systems, existing optical modulators with meandering waveguides face issues such as degradation of extinction ratio, signal distortion, and increased optical path length differences, leading to instability and size constraints.
Innovation Solution
The optical waveguide element features a configuration with turnaround portions where light propagation direction changes, ensuring equal optical path lengths and reduced size by using intersecting waveguides with specific length and width adjustments, and wider waveguide widths at intersecting points to minimize optical loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If meandering sections are added to parallel waveguides to adjust optical path lengths, then optical path length equality is improved, but device complexity and element size increase
Solution Approach 1:
The patent applies asymmetry by making the second portions of the parallel waveguides have different lengths, where the inner waveguide has a longer second portion than the outer waveguide. This asymmetric design compensates for the optical path length difference created by the meandering configuration, achieving optical path length equality without requiring complex meandering sections in all waveguides.
2Manufacturing precision
If meandering sections are added to parallel waveguides to adjust optical path lengths, then optical path length equality is improved, but element size increases
Solution Approach 1:
The patent uses asymmetric length design of the second portions to achieve optical path length equality. By making the inner waveguide's second portion longer than the outer waveguide's second portion, the patent compensates for path differences in a compact manner, avoiding the need for large meandering sections that would increase element size.
3Ease of operation
If the number of curved parts in parallel waveguides is increased to turn light propagation directions, then light direction control is improved, but optical path length differences increase
Solution Approach 1:
The patent applies asymmetry by designing different lengths for the second portions of the parallel waveguides. The inner waveguide has a longer second portion that compensates for the additional path length introduced by its curved configuration, thereby maintaining optical path length equality despite having different numbers or configurations of curved parts.
4Loss of energy
If waveguide width is increased at intersecting parts, then optical loss is reduced, but device complexity increases
Solution Approach 1:
The patent applies local quality by selectively increasing the waveguide width only at the intersecting parts where optical loss occurs, while maintaining the standard width in other sections. This localized modification reduces optical loss at critical points without unnecessarily increasing device complexity throughout the entire waveguide structure.
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 configuration stabilizes modulation operations with reduced wavelength dependency and extinction ratio degradation, allowing for compact design while maintaining efficient light propagation.
Implementation Method 1
optical waveguides causing light to turn between a first direction and a second direction that is an opposite direction of the first direction in a plane of the substrate
Implementation Method 2
wider waveguide widths at intersecting points to minimize optical loss
Data Source
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AI summary
An optical waveguide element (300) includes: a substrate (202); and a plurality of optical waveguides (304) causing light to turn between a first direction and a second direction that is an opposite direction of the first direction in a plane of the substrate (202), the plurality of optical waveguides (304) includes first portions extending in the first direction with a predetermined distance therebetween, second portions extending in a third direction that is different from the first direction, and third portions extending in the second direction, and each of the plurality of optical waveguides (304) except for the optical waveguide in which the second portion extending in the third direction is located on an innermost side in the first direction intersects, at the third portion, another optical waveguide in which the second portion extending in the third direction is located further inward in the first direction.