Optical Coupler Arrays With Vanishing Core Waveguides

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Solution Overview

Problem

Existing optical couplers face challenges in achieving low-loss, high-accuracy connections between optical waveguide devices with different numerical apertures and core sizes, particularly in multichannel configurations, leading to increased insertion losses and back reflections, which are critical issues in telecommunications and sensing applications.

Innovation Solution

The optical coupler array features a common housing structure with vanishing core waveguides and a refractive index profile that gradually changes along its length, allowing for customizable channel-to-channel spacing and refractive indices to optimize coupling, reducing back reflections and improving alignment accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional optical fibers are interfaced with optical waveguide devices having different NAs and core sizes, then coupling between fibers and waveguides is achieved, but insertion losses increase and coupling coefficients decrease

Engineering Contradiction:
Improvecoupling coefficientVSAvoidinsertion loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces an intermediary coupling structure comprising a first coupling region and a second coupling region with progressively changing refractive indices and core sizes. This intermediary structure acts as a transition zone between the conventional optical fiber and the optical waveguide device, gradually matching the mode field diameter and numerical aperture to minimize abrupt discontinuities and reduce insertion losses while maintaining high coupling coefficients.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs progressive parameter changes along the length of the coupling structure, where the refractive index, core size, and numerical aperture transition smoothly from the fiber parameters to the waveguide device parameters. This gradual parameter transformation enables adaptive mode matching and reduces optical loss at the interface.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multichannel optical coupler arrays are configured with fixed channel spacing, then manufacturing is simplified, but adaptability to different optical device interfaces is reduced

Engineering Contradiction:
Improveconfigurability of channel spacingVSAvoidcoupler array configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic or adjustable channel spacing mechanism in the multichannel coupler array, allowing the spacing between adjacent channels to be configured or tuned. This enables the same coupler array structure to adapt to different optical device interfaces with varying channel spacing requirements, enhancing versatility while maintaining a unified design platform.

Inventive Principle:
Principle #15Dynamics

3Productivity

If optical couplers are designed with high coupling coefficients, then light transfer efficiency improves, but back reflections increase which are critical in telecommunications and sensing applications

Engineering Contradiction:
Improvelight transfer efficiencyVSAvoidback reflection
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful back reflection into a beneficial feature by incorporating anti-reflection coatings or impedance matching layers in the coupling structure. These elements are designed to cancel out reflected light through destructive interference or absorb the reflected energy, thereby maintaining high light transfer efficiency while simultaneously suppressing back reflections that would otherwise interfere with telecommunications signals or sensing measurements.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 enables low-loss, high-coupling coefficient interfaces with reduced back reflections, enhancing the performance of optical devices in telecommunications and sensing applications by improving the accuracy and efficiency of light transfer across diverse optical waveguide systems.

Implementation Method 1

a plurality of longitudinal waveguides each positioned at a predetermined spacing from one another, each having a capacity for at least one optical mode of a predetermined mode field profile, each embedded in said common single housing structure proximally to said second end

Methodology Applied
Scientific EffectOptical waveguide: Waveguide (optics)

Implementation Method 2

a refractive index profile that gradually changes along its length, allowing for customizable channel-to-channel spacing and refractive indices to optimize coupling

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

light traveling from said first end to said second end escapes from said inner vanishing core into said corresponding outer core proximally to said intermediate cross section

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3635459B1Optical coupler arrays
Publication Date: 2024.11.20 CHIRAL PHOTONICS INC
  • EP3635459B1 patent drawingFigure 1A~1B
  • EP3635459B1 patent drawingFigure 1C~1D
  • EP3635459B1 patent drawingFigure 2A~2B

AI summary

An optical coupler array comprises a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides is a vanishing core waveguide. Light traveling from a first end to a second end can escape from an inner vanishing core into a corresponding outer core proximally to an intermediate cross section, and can escape from the outer core into a combined waveguide formed by at least two neighboring outer cores proximally to the second end.