Optical Power Splitter with Asymmetric Waveguide Arms
Solution Overview
Problem
Conventional optical power splitters are intolerant to fabrication variations, leading to unpredictable performance due to variability in the splitting ratio among different instances.
Innovation Solution
A structure comprising three waveguide cores with longitudinally offset arms, where the first arm is laterally adjacent to the third arm over a first overlap distance and the second arm is laterally adjacent to the third arm over a second overlap distance, with the first overlap distance being greater than the second, providing an overlap offset to achieve asymmetrical optical splitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional optical power splitter structures are used, then the device is simple to manufacture, but the splitting ratio shows high variability due to fabrication inaccuracies
Solution Approach 1:
The patent applies asymmetry by introducing different longitudinal offsets between the first arm and second arm relative to the third arm. Specifically, the first arm is offset by a first distance and the second arm by a second distance, creating an asymmetric structure that compensates for fabrication variations. This asymmetric design makes the splitting ratio less sensitive to dimensional inaccuracies, thereby improving manufacturing precision without requiring overly complex manufacturing processes.
Solution Approach 2:
The patent applies local quality by varying the overlap distances between arms at different locations along the waveguide. The first overlap distance between the first arm and third arm is made different from the second overlap distance between the second arm and third arm. This local variation in geometric parameters allows precise control of the splitting ratio while maintaining overall structural simplicity.
2Reliability
If symmetrical waveguide structures are used, then the structure is simple and symmetric, but the splitting ratio is highly sensitive to fabrication variations
Solution Approach 1:
The patent deliberately introduces asymmetry through different longitudinal offsets of the first and second arms. The first arm is offset by a first distance and the second arm by a second distance, creating an asymmetric configuration that reduces sensitivity to fabrication variations. This improves reliability and performance predictability by making the device less tolerant to dimensional inaccuracies.
Solution Approach 2:
The patent changes geometric parameters (longitudinal offsets and overlap distances) to optimize performance. By adjusting the first offset distance, second offset distance, first overlap distance, and second overlap distance, the patent achieves desired splitting ratios with reduced sensitivity to fabrication variations, thereby improving reliability.
3Adaptability or versatility
If equal overlap distances are used between arms, then the structure is symmetric and simple, but arbitrary splitting ratios cannot be achieved
Solution Approach 1:
The patent uses asymmetry to achieve arbitrary splitting ratios by setting different overlap distances between arms. The first overlap distance between the first arm and third arm is made different from the second overlap distance between the second arm and third arm. This asymmetric configuration provides the adaptability to achieve any desired splitting ratio while maintaining relative structural simplicity.
Solution Approach 2:
The patent applies local quality by varying the overlap distances at different locations. The first overlap distance and second overlap distance are independently controlled, allowing precise adjustment of the splitting ratio. This local variation provides versatility in achieving arbitrary splitting ratios without requiring complex overall structural changes.
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 allows for adjustable optical coupling ratios and reduced variability in splitting ratios, making it more tolerant to fabrication inaccuracies and enabling efficient, arbitrary splitting ratios with minimal loss, particularly suitable for photonics chips.
Implementation Method 1
The first arm is longitudinally offset from the third arm parallel to the longitudinal axis such that the third arm and the first arm are laterally adjacent over a first overlap distance. The second arm is longitudinally offset from the third arm parallel to the longitudinal axis such that the third arm and the second arm are laterally adjacent over a second overlap distance.
Data Source
AI summary
Structures for an optical power splitter and methods of forming a structure for an optical power splitter. The structure includes a first waveguide core having a first arm, a second waveguide core including a second arm, and a third waveguide core having a third arm laterally positioned between the first arm and the second arm. The third arm has a longitudinal axis. The first arm is longitudinally offset from the third arm parallel to the longitudinal axis such that the third arm and the first arm are laterally adjacent over a first overlap distance. The second arm is longitudinally offset from the third arm parallel to the longitudinal axis such that the third arm and the second arm are laterally adjacent over a second overlap distance. The first overlap distance is greater than the second overlap distance to provide an overlap offset.