Orthogonally Polarized Wavelength Selective Switch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wavelength selective optical switches (WSS) face limitations in increasing data throughput due to fundamental fiber optical nonlinearity, requiring more densely packed and economical devices to support higher-degree network nodes with higher port counts and 'colorless' add/drop ports, which existing technologies struggle to achieve efficiently.
Innovation Solution
The solution involves using polarization properties to co-propagate optical beams at two orthogonal polarizations within a single WSS device, doubling the number of WSS units by employing polarizers, beam combiners, collimators, wavelength dispersing elements, focusing elements, and director arrays to independently redirect wavelength channels, allowing for more compact and cost-effective designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional single-polarization WSS devices are used, then device simplicity is maintained, but the number of WSS units per device is limited and space efficiency is reduced
Solution Approach 1:
The patent applies polarization dimensionality by utilizing orthogonal polarization states (s-polarized and p-polarized beams) as an additional degree of freedom. This allows two independent WSS units to share the same physical device by directing s-polarized and p-polarized light through separate optical paths that converge at the diffraction grating, effectively doubling the capacity without increasing physical footprint
Solution Approach 2:
The patent merges two previously separate WSS units into a single integrated device by combining their optical paths. The beam combiner merges s-polarized and p-polarized beams from different input fibers onto a single diffraction grating, allowing both WSS units to operate simultaneously within one device footprint, reducing space and cost
2Area of stationary object
If more WSS units are packed into a single device, then space efficiency and cost-effectiveness improve, but polarization management complexity increases
Solution Approach 1:
The patent introduces polarization-maintaining components as intermediaries to manage the complexity of handling orthogonal polarizations. Polarization-maintaining fibers and polarization beam combiners act as mediators that preserve and control the polarization states of light beams, enabling multiple WSS units to coexist without interfering with each other's operation
Solution Approach 2:
The patent segments the optical path into distinct polarization channels (s-polarized and p-polarized) that can be independently managed. Each polarization channel has its own input fiber and optical path segment, allowing independent control and simplifying the management of multiple WSS units within a single device
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 enables a doubling of WSS units in a single device, providing space and cost savings while maintaining independent wavelength-selective switching capabilities, thus addressing the need for higher port counts and efficient data throughput in future network nodes.
Implementation Method 1
a polarizing beamsplitter for separating each wavelength group into two sub-beams
Implementation Method 2
a diffraction grating to expand and steer an input optical beam emitted by the input fiber
Data Source
AI summary
The number of wavelength selective switch (WSS) units in a WSS device can be doubled by using polarization properties of optical beams propagating through the WSS device. Beams from different WSS units are orthogonally polarized at the front end, propagated through collimator, wavelength dispersing element, and a focusing element, and impinge on a polarizing beamsplitter, which directs sub-beams at different polarizations to different directing elements of a director array. A polarization diversity configuration at the back end can be used to reduce polarization dependent loss.