Rotatable Ferrule Subassembly for Multicore Fiber Alignment

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Solution Overview

Problem

High-density optical fiber connectors, particularly those with 2D-array MT ferrules, are expensive to produce due to the need for precise control in polishing to ensure coplanarity, leading to high rejection rates and increased costs, and the stacking of fiber ribbons results in bulky and inflexible packages.

Innovation Solution

The development of simplex connectors with a rotatable ferrule subassembly that provides continuous rotational alignment for multicore fibers, allowing precise core-to-device and core-to-core alignment using a ferrule frame assembly, which includes a rotatable collar or frame to facilitate accurate positioning and secure fixation of the fiber within the connector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If 2D-array MT ferrules are used for high-density configurations, then fiber density is improved, but manufacturing cost and complexity increase due to precise polishing requirements and high rejection rates

Engineering Contradiction:
Improvefiber densityVSAvoidpolishing precision requirement
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention divides the traditional single ferrule structure into multiple independent ferrules (first ferrule and second ferrule) that can be separately manufactured and assembled. This segmentation allows each ferrule to be produced with standard polishing requirements rather than requiring the entire 2D array to be perfectly polished, thereby reducing manufacturing complexity and rejection rates while maintaining high fiber density through the multi-ferrule configuration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention nests multiple ferrules within a common connector housing, with the first ferrule and second ferrule positioned adjacently to accommodate multiple fiber cores. This nesting approach allows high-density fiber routing without requiring a single complex 2D-array ferrule, thereby simplifying individual ferrule manufacturing while achieving the desired high fiber count through spatial arrangement.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If 2D-array MT ferrules are used for high-density configurations, then fiber density is improved, but production cost increases due to high rejection rates

Engineering Contradiction:
Improvefiber densityVSAvoidproduction cost
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

By segmenting the fiber termination into multiple independent ferrules, the invention allows each ferrule to be manufactured and inspected separately. This reduces the rejection rate impact, as a defect in one ferrule does not cause rejection of the entire assembly. Standard polishing requirements for individual ferrules result in lower manufacturing costs compared to the stringent 2D-array polishing requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The modular ferrule design allows for selective replacement of only the defective ferrule rather than discarding the entire connector assembly. This recovery approach reduces waste and lowers production costs by maintaining high yield rates for individual ferrules while achieving high overall fiber density through the multi-ferrule configuration.

Inventive Principle:
Principle #34Discarding and recovering

3Quantity of substance

If fiber ribbons are stacked to produce ribbon cordages for 2D configurations, then fiber density is improved, but package size increases and flexibility decreases

Engineering Contradiction:
Improvefiber densityVSAvoidpackage size
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The invention nests multiple ferrules within a compact common housing structure, arranging the first ferrule and second ferrule in an adjacent configuration that optimizes space utilization. This nested arrangement achieves high fiber density without requiring large stacked ribbon cordages, thereby reducing the overall package volume while maintaining the desired fiber count.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Instead of stacking ribbons in a bulky three-dimensional arrangement, the invention transitions to a planar adjacent configuration of multiple ferrules within a flat connector housing. This dimensional change from vertical stacking to horizontal arrangement reduces package height and overall volume while achieving the same fiber density through efficient spatial distribution.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Quantity of substance

If fiber ribbons are stacked to produce ribbon cordages for 2D configurations, then fiber density is improved, but flexibility is reduced

Engineering Contradiction:
Improvefiber densityVSAvoidcordage flexibility
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The nested ferrule configuration within a flexible common housing allows the connector to bend and flex more easily compared to rigid stacked ribbon structures. The adjacent ferrule arrangement creates a more compact and flexible assembly that can accommodate cable routing requirements without the bulk and stiffness associated with stacked ribbon cordages.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP2548061B1Simplex connectors for multicore optical fiber cables
Publication Date: 2020.06.17 OFS FITEL LLC
  • EP2548061B1 patent drawingFigure 1A~1B
  • EP2548061B1 patent drawingFigure 2A~2C
  • EP2548061B1 patent drawingFigure 3~5

AI summary

An optical fiber cable connector includes a ferrule subassembly, wherein a ferrule is mounted into a receptacle including a barrel section having a flange at its base. The ferrule subassembly is loaded into an enclosure having a plug housing at its lead end. The plug housing provides a connection between an endface of a multicore fiber mounted into the ferrule and a corresponding surface in a mating socket. A collar is rotatably mounted onto the barrel section such that it butts up against the flange. The barrel section fits within the collar and the collar fits within the plug housing. The ferrule, receptacle, barrel section, mounted multicore fiber, enclosure, and plug housing have a common longitudinal axis. The ferrule, receptacle, barrel section and mounted multicore fiber are thus continuously rotatable with respect to the enclosure and plug housing, thereby enabling rotational precise alignment of the multicore fiber within the enclosure.