Stress-Free Optical Bench Mounting for WSS Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanical packaging of wavelength selective switches (WSSs) in optical communication networks faces challenges due to the large footprint and complex assembly of free-space optics and electrical connections, leading to increased costs and reduced manufacturing yields, as well as potential thermal stress issues from mismatched thermal expansion coefficients.
Innovation Solution
A WSS module design featuring an optical bench attached to the enclosure base with a combination of fixed and movable mounts, where the fixed mount ensures optical alignment and the movable mounts accommodate thermal expansion differences, reducing stress and allowing for more compact packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flexible printed circuit board (flex-PCB) is used to provide electrical connections within a hermetic enclosure, then electrical connection between the switching engine and control system is achieved, but assembly time increases, operator skill requirements increase, and manufacturing yields decrease
Solution Approach 1:
The patent extracts the flex-PCB and multi-pin hermetic connector from the assembly, replacing them with a simplified direct-mount approach where the optical switching engine is mounted directly to the enclosure wall. This eliminates the complex assembly steps involving flex-PCB fitting and alignment, thereby improving manufacturing yield while maintaining electrical connection reliability through direct mounting.
2Adaptability or versatility
If free-space optics with large footprint are used in WSS architecture, then versatile wavelength switching performance is achieved, but enclosure size increases
Solution Approach 1:
The patent transitions from a planar layout to a three-dimensional configuration by mounting the optical switching engine vertically on the enclosure wall and arranging optical components in multiple layers. This vertical stacking approach reduces the horizontal footprint while maintaining the versatile wavelength switching capability through proper optical path design.
3Manufacturing precision
If optical components are rigidly mounted to accommodate thermal expansion differences, then optical alignment is maintained, but thermal stress increases
Solution Approach 1:
The patent changes the mounting parameters by using compliant or adjustable mounting mechanisms that allow for thermal expansion and contraction. This enables the optical components to maintain proper alignment across temperature variations without generating excessive thermal stress, as the mounting system can accommodate dimensional changes.
4Reliability
If multiple fiber feed-throughs and flex-PCBs are fitted and aligned inside the package, then required electrical and optical connections are achieved, but assembly complexity increases
Solution Approach 1:
The patent merges the electrical connection function and optical mounting function into a single integrated structure. The optical switching engine is directly mounted to the enclosure wall, combining what were previously separate functions (flex-PCB electrical connections and optical component mounting). This integration significantly reduces assembly complexity while maintaining connection reliability.
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 reduces thermal stress, maintains optical alignment, and allows for a more compact and cost-effective WSS module with improved manufacturing efficiency, capable of operating across a wider temperature range without performance degradation.
Implementation Method 1
the plurality of mounts including at least one movable mount supporting movement of the optical bench in a plane parallel to the optical bench and at least one fixed mount maintaining optical alignment between the dispersive element and the array of switching elements
Data Source
AI summary
An optical bench in a wavelength selective switch (WSS) is mounted using a combination of fixed mounts and stress-free mounts. The WSS is packaged in an enclosure including a base, a sidewall, and a lid. The optical switching engine is attached directly to the base. The optical bench is attached to the base and the optical components supported thereon are aligned with the array of switching elements of the switching engine. The optical bench is attached to the base with at plurality of mounts, which include at least one movable mount supporting movement of the optical bench in a plane parallel to the optical bench and at least one fixed mount maintaining optical alignment between the dispersive element and the array of switching elements.