Mode-Matched Fiber Stub Connections for Multimode Reach Extension
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Solution Overview
Problem
Multimode optical fibers face challenges in extending reach and increasing data rates due to modal dispersion, with replacing deployed cables being costly and difficult, and there is a need for improved interoperability with single-mode transceivers.
Innovation Solution
The use of single-mode fiber stubs with mode field diameters matching those of multimode fibers, secured by ferrules, to form splice joints and enable single-mode transmission over existing multimode optical fibers, reducing modal dispersion and insertion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multimode optical fiber is used for short distance communications, then ease of operation and historical compatibility are improved, but bandwidth-distance product and transmission reach are worsened due to modal dispersion
Solution Approach 1:
The patent changes the operating wavelength parameter from the traditional 850 nm to 1310 nm or 1550 nm. This parameter change allows the multimode fiber to operate in a wavelength range where chromatic dispersion is minimized, thereby extending the transmission reach and improving bandwidth-distance product while maintaining the existing multimode fiber infrastructure and ease of operation.
2Ease of operation
If multimode optical fiber is used for short distance communications, then ease of operation is improved, but data rate capability is worsened due to modal dispersion
Solution Approach 1:
The patent changes the operating wavelength from 850 nm to 1310 nm or 1550 nm, which reduces chromatic dispersion and enables higher data rate transmission over the existing multimode fiber without requiring replacement of the fiber cable, thus maintaining ease of operation while improving data rate capability.
3Length of moving object
If existing multimode fiber cables are replaced with single-mode fiber, then transmission reach and data rate are improved, but time, labor, and expense increase
Solution Approach 1:
The patent performs preliminary action by optimizing the existing multimode fiber system through wavelength change before replacement becomes necessary. By operating at 1310 nm or 1550 nm, the system achieves extended reach and higher data rates immediately, delaying or eliminating the need for time-consuming cable replacement projects.
4Length of moving object
If existing multimode fiber cables are replaced with single-mode fiber, then transmission reach is improved, but cost increases
Solution Approach 1:
The patent enables the existing multimode fiber infrastructure to serve itself by optimizing its performance through wavelength change. The system achieves extended reach and higher data rates without requiring external intervention in the form of cable replacement, thereby avoiding the significant costs associated with replacing buried fiber cables.
5Adaptability or versatility
If single-mode transceivers are used with multimode fiber, then interoperability is improved, but transmission performance is worsened due to mode field diameter mismatch
Solution Approach 1:
The patent changes the operating wavelength parameter to 1310 nm or 1550 nm, where the mode field diameter of multimode fiber is closer to that of single-mode fiber. This parameter change reduces mode field diameter mismatch when single-mode transceivers communicate over multimode fiber, thereby improving both interoperability and transmission performance simultaneously.
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 allows for higher data rates and reduced costs by upgrading multimode fiber systems without replacing existing cables, improving transmission efficiency and reducing modal dispersion.
Implementation Method 1
The ferrule includes a front end that presents the single-mode fiber stub for optical coupling
Data Source
AI summary
Disclosed herein is a fiber optic system including at least one fiber optic cable assembly having a multimode optical fiber for communication of an optical data signal at an operating wavelength and a devices having a single-mode fiber stub with a mode field diameter within 20% of the mode field diameter of the fundamental mode of the multimode optical fiber at the operating wavelength. The single-mode fiber stub is secured to a ferrule, and a center of a core of the single-mode fiber stub is within 0.5 μm of a center of the ferrule. An end of the single-mode fiber stub that extends to or beyond the back end of the ferrule and forms an optical connection with the multimode optical fiber where the center of the single-mode fiber stub is within 2 μm of a center of the multimode optical fiber.