Optical Circuit Board Loop-Back Alignment Without Reflective Films
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Solution Overview
Problem
The existing optical devices require extra components and processes for aligning optical circuit boards and fiber arrays, leading to increased size, cost, and reduced efficiency due to the need for additional alignment members and complex installation procedures.
Innovation Solution
Incorporating a loop-back circuit on the optical circuit board that returns aligning light to the fiber array, allowing for alignment without additional components or processes, and arranging signal and aligning ports to minimize reflection losses and facilitate parallel translation for accurate coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an aligning optical waveguide is provided separately from the main circuit section, then alignment accuracy is improved, but the size of the optical circuit board increases
Solution Approach 1:
The aligning optical waveguide is merged with the main circuit section to form an integrated waveguide structure. The aligning light propagation path is constructed using the same optical waveguide layers and routing as the main circuit, eliminating the need for separate aligning waveguide structures. This integration maintains alignment accuracy while reducing the overall board area.
2Strength
If the optical circuit board is mounted on a package with a covering wall, then mechanical protection is improved, but alignment becomes difficult due to light blockage
Solution Approach 1:
The alignment observation is shifted from the lateral direction (blocked by package wall) to the vertical direction (through the optical circuit board). The aligning light is made to propagate through the optical waveguide and exit from the end face opposite to where the aligning fiber is coupled. This allows observation of the aligning light intensity from the back side of the board, bypassing the package wall obstruction.
3Manufacturing precision
If alignment is performed before mounting on package, then alignment accuracy is improved, but mounting efficiency deteriorates due to hindered processes
Solution Approach 1:
The optical circuit board performs self-alignment through its own optical waveguide structure. The aligning light propagates through the integrated waveguide and emerges at the opposite end face, allowing the board itself to provide the alignment reference without requiring external alignment fixtures or pre-alignment procedures. This enables alignment to be performed after package mounting.
4Ease of operation
If a reflection film or mirror is installed for alignment, then alignment capability is improved, but manufacturing cost increases
Solution Approach 1:
The alignment function is extracted from the mechanical structure (reflection film or mirror) and implemented through the optical waveguide's inherent light propagation characteristics. The aligning light intensity observation is achieved by detecting the light emerging from the optical waveguide end face, eliminating the need for separate reflection films or mirrors.
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 solution enables cost-effective alignment of optical circuit boards and fiber arrays without extra members or processes, improving alignment accuracy and reducing the size of the optical device while maintaining high precision and efficiency.
Implementation Method 1
an optical waveguide configured to combine aligning light from the fiber array; a loop-back circuit configured to return the aligning light combined by the optical waveguide to the fiber array
Data Source
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AI summary
An optical circuit board of the present invention is mounted with a loop-back circuit for returning aligning light to the fiber array in the vicinity of the fiber array connection end. Since an aligning loop-back circuit can be formed in an optical waveguide pattern, a production cost does not increase in comparison to an optical circuit board of the related art. The aligning light combined from the optical fiber to the aligning port of the optical circuit board is returned to the optical fiber around the loop-back circuit. Therefore, it is possible to perform alignment using the returned light. That is, alignment can be performed while being mounted on a package without installing a light-reflecting film or mirror.