Cross Optical Waveguide Tapering Intersection Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cross optical waveguide structures experience significant intersection loss due to the interference of light modes at the intersection points of optical waveguides, which current technologies have not adequately addressed.
Innovation Solution
A cross optical waveguide structure is designed with tapering portions on either side of the intersection, where the mode field radius of the light is reduced, allowing the light to be collected in the intersection portion, thereby minimizing the overlap and interference of light modes, and using a cladding layer with a lower refractive index to enhance light propagation and reduce manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If optical waveguides are made to intersect in the same plane to form a cross optical waveguide structure, then the device can achieve compact integration and simplified routing, but significant intersection loss occurs due to light mode interference at the intersection points
Solution Approach 1:
The patent applies preliminary action by introducing tapering portions before the intersection point to pre-adjust the mode field radius of light propagating through the waveguides. These tapering sections are designed to reduce the mode field radius gradually, so that when the light reaches the intersection portion, the reduced mode field radius minimizes the overlap and interference between light modes from different waveguides, thereby reducing intersection loss.
Solution Approach 2:
The patent changes the physical parameter of the waveguide width by introducing tapering portions with gradually varying widths. This parameter change allows the mode field radius to be adjusted continuously along the waveguide path, enabling optimization of the light mode distribution at the intersection point to minimize interference and energy loss.
2Loss of energy
If the mode field radius is reduced at the intersection portion to minimize light mode interference, then intersection loss is reduced, but the waveguide structure becomes more complex with additional tapering portions
Solution Approach 1:
The patent segments the waveguide structure into distinct functional portions: fixed-width portions for normal light propagation and tapering portions for mode field radius adjustment. This segmentation allows the tapering portions to be strategically placed only where needed (before intersection points) rather than throughout the entire waveguide, thereby reducing overall structural complexity while achieving the desired loss reduction.
Solution Approach 2:
The patent applies local quality by introducing tapering portions only in specific locations where the mode field radius needs to be reduced before an intersection point, while maintaining fixed-width portions in other sections where the waveguide should preserve its normal propagation characteristics. This localized modification reduces the overall complexity compared to uniformly tapering the entire waveguide structure.
3Loss of energy
If tapering portions are introduced to reduce mode field radius, then light mode interference is minimized, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs curved tapering portions with gradual width transitions rather than abrupt changes or sharp angles. This curved geometry allows for smoother mode field radius reduction, minimizing discontinuities that would require high precision manufacturing. The gradual curvature can be more easily achieved in standard fabrication processes compared to sharp geometric features.
Solution Approach 2:
The patent uses gradual parameter changes in the tapering portions, where the width varies continuously and smoothly rather than in discrete steps or with sharp transitions. This gradual parameter variation reduces the sensitivity to manufacturing variations and allows for more tolerant fabrication processes while still achieving the desired mode field radius reduction effect.
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 effectively reduces intersection loss by minimizing light mode interference and recombination loss, while also simplifying the manufacturing process by allowing for increased tapering portion widths and reducing the difficulty and accuracy required in processing.
Implementation Method 1
a cladding portion (4) that is formed on outer periphery of the first optical waveguide (1) and the second optical waveguide (2), and that has a smaller refractive index than the first optical waveguide (1), the second optical waveguide (2), and the intersection portion (3)
Implementation Method 2
a first tapering portion (1c) that extends from the first fixed-width portion (1a) toward the second fixed-width portion (1b), and a width thereof decreases toward the second fixed-width portion (1b)
Data Source
AI summary
A cross optical waveguide structure includes a first optical waveguide, a second optical waveguide, and an intersection portion positioned in the same plane. The first optical waveguide includes a first fixed-width portion, a second fixed-width portion, a first tapering portion, and a second tapering portion. The second optical waveguide includes a third fixed-width portion, a fourth fixed-width portion, a third tapering portion, and a fourth tapering portion. The intersection portion is linked to the first to the fourth tapering portions having such a tapering shape that a mode field radius of the light input to the first fixed-width portion, the second fixed-width portion, or the third fixed-width portion, and the fourth fixed-width portion is reduced by the first tapering portion, the second tapering portion, the third tapering portion, the fourth tapering portion, respectively, and the light is collected in the intersection portion.