Multi-Core Few-Mode Optical Fiber for Signal Differentiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-core optical fibers have similar transmission signals that are difficult to distinguish, especially in sensing applications, and their manufacturing process is complex, limiting their application range.
Innovation Solution
A multi-core few-mode optical fiber with distinct refractive index and diameter differences between core layers, supported by a plasma chemical vapor deposition process, allowing for simple signal identification and improved lateral deformation sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multi-core optical fiber with identical simple step-type waveguides is used, then the manufacturing process is simplified, but the transmission signals become similar and difficult to distinguish
Solution Approach 1:
The patent applies local quality by giving each fiber core a distinct refractive index profile (graded-index rather than step-type) and different core diameters. This local differentiation in optical properties allows each core to have unique transmission characteristics, enabling signal distinguishability while maintaining a relatively simple manufacturing process through controlled material composition variations.
Solution Approach 2:
The patent changes key optical parameters of the fiber cores, specifically the refractive index distribution (using graded-index profiles with different alpha values) and core diameters. By varying these parameters across different cores, the transmission signals become distinctly different, solving the signal identification problem while the changes are achieved through standard optical fiber manufacturing techniques.
2Reliability
If multi-core optical fiber with large number of symmetrically distributed cores is used, then crosstalk suppression is improved, but the application range is limited to communication field only
Solution Approach 1:
The patent applies asymmetry by using an irregular distribution pattern for the fiber cores rather than symmetric arrangements. The cores are positioned at different locations with varying distances from the central axis, creating asymmetric optical paths that provide both crosstalk suppression through spatial separation and enhanced sensitivity to lateral deformations, thereby expanding applicability to sensing fields.
Solution Approach 2:
The patent transitions from conventional two-dimensional core arrangements to a three-dimensional irregular distribution within the cladding cross-section. This dimensional change allows cores to be positioned at varying radial distances and angular positions, enabling simultaneous achievement of crosstalk suppression (through adequate spacing) and sensing capability (through asymmetric deformation response).
3Device complexity
If conventional single-core communication optical fiber is used, then the sensor structure is simple, but the sensor cannot sense lateral deformation effectively
Solution Approach 1:
The patent uses local quality differentiation among multiple fiber cores, where each core's specific position and optical properties create unique sensitivity patterns to lateral deformations. This allows the sensor structure to remain relatively simple (using standard multi-core fiber technology) while achieving enhanced lateral deformation sensing capability through the selective response of differently positioned cores.
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
The fiber enables effective signal differentiation and enhanced sensitivity to lateral deformation, supporting multiple polarization modes with reduced crosstalk and leakage, suitable for shape sensing applications.
Implementation Method 1
A multi-core few-mode optical fiber with distinct refractive index and diameter differences between core layers, supported by a plasma chemical vapor deposition process
Data Source
Figure 1~2
Figure 3~4
AI summary
Disclosed are a multi-core and few-mode optical fiber and a manufacture method therefor. The multi-core and few-mode optical fiber comprises a fiber body and a cladding layer (3). The fiber body comprises at least one first fiber core (1) and at least two second fiber cores (2), which are a determined distance away from the center of the fiber body and spaced with each other. Each of the first fiber core (1) and the second fiber core (2) comprises at least one circulating layer and a core layer arranged outside the circulating layer. Arbitrary two adjacent core layers of the first fiber core (1) and the second fiber core (2) have different refractive indexes or diameters, and at least one of the effective refractive index and the diameter of the first fiber core (1) is different from that of the second fiber core (2). The cladding layer (3) surrounds the first fiber core (1) and the second fiber core (2), and the refractive index of the cladding layer (3) is lower than that of the first fiber core (1) and the second core (2), and is higher than that of the outermost core layer of the first fiber core (1) and the second fiber core (2). The method solves the problem that the transmission signals are similar and difficult to be distinguished in a signal transmission process when the optical fiber is applied in the sensing and communication field.