Micro Bi-Directional Optical Sub-Assembly Using Thin Film Filter
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Solution Overview
Problem
Current bi-directional optical sub-assembly (BOSA) modules in passive optical networks require complex manufacturing processes, high costs, and large form factors due to the use of metal components and laser welding, which complicates alignment and increases production costs.
Innovation Solution
Integration of transmitter and receiver optical sub-assemblies into a single micro BOSA package using a modified optical routing scheme with reconfigured paths and molded plastic resin, eliminating the need for laser welding and simplifying the assembly process, while employing a thin film filter for wavelength separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal components and laser welding are used in BOSA modules, then structural strength and reliability are improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the TOSA and ROSA into a single integrated TO package, merging two separate assemblies into one unified structure. This integration eliminates the need for separate metal housings and laser welding processes, reducing manufacturing complexity while maintaining structural integrity through the unified plastic housing design.
Solution Approach 2:
The patent replaces the mechanical laser welding process with a molded plastic resin bonding system. The plastic housing integrates both optical sub-assemblies through molding processes, substituting complex mechanical joining methods with a simpler, more cost-effective plastic bonding approach that maintains structural reliability.
2Strength
If metal components and laser welding are used in BOSA modules, then structural strength is improved, but production cost increases
Solution Approach 1:
The patent employs a molded plastic resin housing that is cost-effective and suitable for high-volume production. The plastic components replace expensive metal parts and complex welding processes, reducing production costs while providing sufficient structural strength for the application requirements.
Solution Approach 2:
By merging TOSA and ROSA into a single package with a unified plastic housing, the patent eliminates the need for separate metal components and welding operations, directly reducing material costs and manufacturing expenses while maintaining adequate structural strength.
3Reliability
If separate TOSA and ROSA packages are used, then reliability is improved, but form factor increases
Solution Approach 1:
The patent merges separate TOSA and ROSA packages into a single integrated TO package, reducing the overall form factor by eliminating the need for two separate sealed housings and their associated mounting structures, while maintaining the reliability of both optical sub-assemblies within the unified package.
4Reliability
If complex optical routing is used, then optical performance is improved, but alignment difficulty increases
Solution Approach 1:
The patent incorporates preliminary alignment features directly into the molded plastic housing structure, such as precision-molded mounting positions and optical path guides. These pre-built alignment mechanisms ensure accurate optical alignment without requiring complex post-assembly adjustment procedures, maintaining optical performance while simplifying the manufacturing process.
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 manufacturing complexity, lowers costs, and improves performance by enabling a compact, efficient design suitable for single mode fiber applications and optical network units, with simplified alignment and reduced device size.
Implementation Method 1
a thin film filter (TFF) positioned such that the first optical signal transmitted from the TOSA is reflected by the TFF toward the optical communication window
Implementation Method 2
a thin film filter (TFF) positioned such that the second optical signal received from the optical communication window passes through the TFF and to the ROSA
Data Source
AI summary
A BOSA package comprising only one cylindrical TO package comprising a ROSA and a TOSA, and an optical port in optical communication with the ROSA and the TOSA. Also disclosed is a TO package comprising a TOSA for transmitting a first optical signal, a ROSA for receiving a second optical signal, an optical communication window, and a TFF positioned such that the first optical signal transmitted from the TOSA is reflected by the TFF toward the optical communication window and the second optical signal received from the optical communication window passes through the TFF and to the ROSA.