Directional Coupler Phase Distortion Reduction

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Solution Overview

Problem

Optical resonator gyroscopes face errors due to unequal loss coefficients between optical modes in directional couplers, leading to phase deviations and resonance distortions.

Innovation Solution

A directional coupler design that sets a coupling ratio and adjusts the separation distance and length of coupler waveguides to minimize phase deviation caused by differences in loss coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the separation distance between coupler waveguides is reduced to increase coupling strength, then the coupling ratio improves, but the phase deviation increases due to unequal loss coefficients

Engineering Contradiction:
Improvecoupling ratioVSAvoidphase deviation
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by adjusting the separation distance and length of the coupler waveguides to optimize the coupling ratio while minimizing phase deviation. By varying these geometric parameters, the system achieves a balance between coupling strength and phase matching, resolving the contradiction between power transfer efficiency and measurement precision.

Inventive Principle:
Principle #35Parameter changes

2Power

If the length of coupler waveguides is increased to improve coupling ratio, then energy transfer efficiency improves, but the phase deviation increases due to accumulated loss differences

Engineering Contradiction:
Improveenergy transfer efficiencyVSAvoidphase deviation
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The patent utilizes parameter changes by optimizing the length of the coupler waveguides. By carefully selecting the length parameter, the system achieves sufficient energy transfer efficiency while limiting the accumulation of phase deviation caused by unequal loss coefficients, thus resolving the contradiction between power transfer and measurement precision.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the separation distance between coupler waveguides is adjusted to minimize phase deviation, then measurement precision improves, but the coupling ratio decreases

Engineering Contradiction:
Improvephase deviationVSAvoidcoupling ratio
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent applies parameter changes by finding an optimal separation distance that balances coupling ratio and phase deviation. This optimization process resolves the contradiction by identifying a separation distance value that provides acceptable coupling strength while minimizing phase deviation to improve measurement precision.

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If loss coefficients between optical modes are made equal to reduce phase deviation, then measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improvephase deviationVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by adjusting the geometric parameters (separation distance and length) of the coupler waveguides to achieve approximately equal loss coefficients for different optical modes. This approach reduces phase deviation and improves measurement precision without requiring complex additional components, thus resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #35Parameter changes

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 design achieves reduced phase deviation, minimizing errors in rotation rate measurements and stabilizing optical resonance in gyroscopes.

Implementation Method 1

When two waveguides are positioned sufficiently close to each other in a parallel fashion, propagation modal fields generated by light waves (signals) in a first coupler waveguide of the directional coupler overlaps into the other second coupler waveguide causing optical modes in the coupler waveguides to couple therein transferring energy from the light waves in the first waveguide to light waves in the second waveguide.

Methodology Applied
Scientific EffectOptical mode coupling: Waveguide (optics)

Data Source

PatentEP4530688A1Directional coupler with reduced phase distortion
Publication Date: 2025.04.02 HONEYWELL INTERNATIONAL INC
  • EP4530688A1 patent drawingFigure 1
  • EP4530688A1 patent drawingFigure 2A~2C
  • EP4530688A1 patent drawingFigure 3A~3B

AI summary

A directional coupler with reduced phase deviation is provided. The directional coupler includes a first coupler waveguide and second coupler waveguide. At least one of a spaced distance between the first coupler waveguide and the second coupler waveguide and a length of the first coupler waveguide and the second coupler waveguide selected to achieve an acceptable phase deviation and a set coupling ratio. The phase deviation is caused by a difference in loss coefficients between a first optical mode in the first coupler waveguide and a second optical mode in the second coupler waveguide.