Optical Coupling Structure for Array Amplifier Modules

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Solution Overview

Problem

Existing optical coupling structures between optical fiber arrays and semiconductor optical amplifier arrays suffer from wavelength-dependent optical coupling loss and edge reflection, which degrades the performance of semiconductor optical amplifiers and complicates the formation of obliquely cut optical fiber end faces.

Innovation Solution

An optical coupling system that optically couples beams to the end face of the semiconductor optical amplifier array in parallel with the waveguide direction and to the optical fiber array obliquely in a non-array direction, using a combination of lenses to refract beams such that they are incident parallel to the optical fiber axis, reducing wavelength dependence and edge reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If beams of light signals are made oblique to the end faces of optical fibers and SOAs to suppress edge reflection, then edge reflection is reduced, but wavelength dependence of optical coupling loss increases

Engineering Contradiction:
Improveedge reflectionVSAvoidwavelength dependence of optical coupling loss
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces a second optical axis in a direction substantially orthogonal to the first optical axis. The end faces of optical fibers are formed obliquely with respect to the second optical axis, while light signals propagate along the first optical axis. This dimensional separation allows the end face inclination to suppress edge reflection without affecting the parallel incidence of light signals, thereby resolving the contradiction between reducing edge reflection and maintaining low wavelength dependence.

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

2Reliability

If beams of light signals are made parallel to the axial direction of optical fibers to reduce wavelength dependence, then wavelength dependence is reduced, but edge reflection increases and SOA characteristics degrade

Engineering Contradiction:
Improvewavelength dependence of optical coupling lossVSAvoidedge reflection
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent separates the functions of light propagation and reflection suppression into different dimensions. Light signals propagate parallel to the optical fiber axis along the first optical axis, while the end faces are inclined with respect to the second optical axis (orthogonal to the first). This allows parallel incidence for low wavelength dependence while the orthogonal inclination suppresses edge reflection.

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

3Object-affected harmful factors

If end faces of optical fibers are made oblique in the array direction to suppress edge reflection, then edge reflection is reduced, but manufacturing complexity increases significantly

Engineering Contradiction:
Improveedge reflectionVSAvoidformation of oblique end faces
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the direction of end face inclination from the array direction to a direction orthogonal to the array direction (second optical axis direction). This allows all optical fibers in the array to have their end faces inclined at the same angle relative to the second optical axis, making the inclination direction consistent across the array and significantly simplifying manufacturing processes.

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

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 configuration effectively suppresses edge reflection and reduces wavelength-dependent optical coupling loss, ensuring efficient and uniform optical coupling across multiple channels with minimal degradation of semiconductor optical amplifier characteristics.

Implementation Method 1

using a combination of lenses to refract beams such that they are incident parallel to the optical fiber axis

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2637052B1Optical coupling structure and array optical amplification module
Publication Date: 2019.09.25 FUJITSU LTD
  • EP2637052B1 patent drawingFigure 1
  • EP2637052B1 patent drawingFigure 2
  • EP2637052B1 patent drawingFigure 3

AI summary

An optical coupling structure includes an optical amplifier array configured to include a plurality of optical amplifiers arranged in an array direction, an optical fiber array configured to include a plurality of optical fibers arranged in the array direction, and an optical coupling system that optically couples the optical amplifier array and the optical fiber array, wherein, in a non-array direction orthogonal to the array direction, the optical coupling system optically couples beams of light signals to an end face of the optical amplifier array in parallel with a waveguide direction of the optical amplifiers, and optically couples the beams to an end face of the optical fiber array obliquely to the end face of the optical fiber array in the non-array direction.