Optical Waveguide Core Layout for Uniform Channel Loss
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Solution Overview
Problem
Existing manufacturing methods of optical waveguides result in variations of transmission loss between channels due to uneven refractive index distribution and improper consideration of boundary lines between irradiated and non-irradiated regions, leading to potential manufacturing inconsistencies.
Innovation Solution
A manufacturing method that includes a core layer with specific refractive index distribution, defined core portion-forming regions, and strategic placement of marks and cladding portions to ensure uniform refractive index transitions, minimizing transmission loss variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the monomer moves in the core layer during irradiation to generate refractive index difference, then the optical waveguide structure is formed, but the refractive index variation between adjacent clad portions becomes large
Solution Approach 1:
The patent applies local quality by creating different refractive index characteristics in different regions of the core layer. Specifically, it forms a first core portion with a first refractive index and a second core portion with a second refractive index, where the refractive indices are deliberately made different. This allows each region to have optimized optical properties for its specific function, while the patent controls the boundary line density to prevent excessive refractive index variation.
2Productivity
If the optical waveguide film is cut out from the optical waveguide sheet, then the final product is obtained, but the transmission loss varies between channels
Solution Approach 1:
The patent applies preliminary action by pre-forming the core layer with specific refractive index distribution and boundary line patterns before the cutting process. It deliberately designs the arrangement of boundary lines between irradiated and non-irradiated regions to have low density, and pre-positiones core portions at specific locations. This preliminary structuring ensures that when the optical waveguide film is cut out, the transmission loss remains consistent across channels, eliminating the need for post-cutting adjustments.
3Manufacturing precision
If the boundary line density is high, then the refractive index difference is large, but the transmission loss variation increases
Solution Approach 1:
The patent applies parameter changes by controlling the density of boundary lines between irradiated and non-irradiated regions. It specifically designs the core layer so that the boundary line density is low, which results in smaller refractive index differences. Additionally, it controls the area ratio of core portions to cladding portions and adjusts the refractive index values to maintain transmission loss variation within 0.05 dB or less across all channels, achieving both precision and stability.
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
The method enables the production of optical waveguides with reduced transmission loss variations by optimizing the arrangement and refractive index distribution within the core layer, enhancing channel consistency.
Implementation Method 1
the monomer moves in an in-plane direction orthogonal to a film thickness in the core layer during the irradiation with the active light beam and generates a difference in refractive index between an irradiated region and a non-irradiated region
Data Source
AI summary
The manufacturing method of an optical waveguide of the present invention includes a step of preparing a workpiece which includes a core layer including a core portion-forming region and has a sheet shape and a step of cutting out an optical waveguide from an inside of the core portion-forming region in the workpiece. The core layer satisfies all of the following requirements (a), (b), and (c).(a) the core layer contains a polymer and a monomer, and has a refractive index distribution based on a difference in concentration of the monomer or a difference in concentration of a structure derived from the monomer.(b) the core portion-forming region includes a plurality of first core portions, second core portions provided on both sides of the first core portion, and a first side cladding portion provided between the first core portion and the second core portion, and the core portion-forming region is defined as that a plurality of the second core portions are positioned at an outer edge of the core portion-forming region.(c) the core portion-forming region is a region where a total area ratio occupied by the first core portion and the second core portion is 50% or more in a 1 mm-square range.