Asymmetric Waveguide Grating Router for CWDM
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current waveguide grating routers for CWDM applications suffer from increased size and loss due to the inclusion of additional sections, which reduces the number of devices that can be included on each wafer and increases crosstalk.
Innovation Solution
The solution involves removing the central section C and modifying the remaining sections A and B to produce a nonzero diffraction order, using an asymmetric arrangement of two curved arrays with opposite curvatures and rotation angles, resulting in a smaller and more efficient grating structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an additional central section C is included in the grating to produce nonzero diffraction order for CWDM applications, then the diffraction order requirement is met, but the size of the grating increases substantially
Solution Approach 1:
The patent removes the additional central section C from the grating structure while maintaining the nonzero diffraction order through modified rotation angles in the remaining sections A and B. This extraction eliminates the size-increasing element while preserving the functional requirement.
Solution Approach 2:
The patent employs asymmetric rotation angles for sections A and B (θA ≠ θB) to generate nonzero diffraction order without requiring the additional central section C. This asymmetric configuration allows the grating to achieve the required diffraction order while maintaining a compact size.
2Manufacturing precision
If an additional central section C is included in the grating, then the diffraction order requirement is met, but the loss and crosstalk increase
Solution Approach 1:
By removing the additional central section C that causes increased loss and crosstalk, the patent reduces energy loss while maintaining the required diffraction order through asymmetric rotation angles in sections A and B.
3Manufacturing precision
If an additional central section C is included in the grating, then the diffraction order requirement is met, but the number of devices that can be included on each wafer decreases
Solution Approach 1:
By eliminating the space-consuming central section C, the patent increases the number of gratings that can be fabricated on each wafer, thereby improving manufacturing productivity while maintaining the required diffraction order.
4Productivity
If the grating size is reduced by removing section C, then more devices can be included on each wafer, but the diffraction order may become zero
Solution Approach 1:
The patent uses asymmetric rotation angles (θA ≠ θB) in sections A and B to generate nonzero diffraction order even after removing section C. This asymmetric configuration ensures that the diffraction order requirement is met while maintaining the reduced grating size for higher productivity.
Solution Approach 2:
By changing the rotation angle parameters of sections A and B from the conventional symmetric configuration to an asymmetric configuration, the patent achieves nonzero diffraction order in a reduced-size grating structure without section C.
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 size and loss of the waveguide grating while maintaining or exceeding the diffraction order requirements, allowing for more devices on each wafer and improved performance in CWDM applications.
Implementation Method 1
a grating having a plurality of waveguides forming arms of the grating, wherein: successive arms of the grating have a path length difference ΔL
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A planar optical device useful as a low order wavelength router is realized by using a waveguide grating having two curved arrays of opposite curvatures. The diffraction order is determined by the angles of rotation of the two curved arrays, and any nonzero order less than about 30, for example, can be realized. This arrangement is smaller, and performs better than a conventional grating using a combination of three curved arrays.