Polarization Rotation Means for Waveguide Birefringence Compensation

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Solution Overview

Problem

Existing devices for determining polarization information of target samples are limited by the need for direct access to the sample, making it difficult to analyze samples in inaccessible areas, such as within hollow bodies or turbid environments.

Innovation Solution

A device utilizing a waveguide to guide a polarized light beam to and from the target sample, with polarization rotation means to compensate for waveguide birefringence, allowing for the analysis of polarization information without direct line-of-sight access, using a Faraday rotator to rotate polarimetric components and photodetectors to calculate polarization information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a light beam in direct line of sight is used to determine polarization information, then measurement precision is improved, but accessibility to target samples is worsened

Engineering Contradiction:
Improvepolarization information determinationVSAvoidaccessibility to target samples
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

An optical fiber is introduced as an intermediary element to transmit the light beam between the measurement system and the target sample. This allows the light beam to reach samples in inaccessible locations (within hollow bodies, turbid environments) while maintaining the polarization measurement capability, thus resolving the contradiction between measurement precision and accessibility

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If polarization-maintaining optical fiber is used to guide the light beam, then accessibility to target samples is improved, but device complexity is worsened

Engineering Contradiction:
Improveaccessibility to target samplesVSAvoidoptical system configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The optical fiber serves as a mediator that simplifies the overall system by providing a ready-made solution for light transmission in difficult-to-reach areas, avoiding the need for complex free-space optical paths with multiple mirrors and lenses

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system compensates for waveguide birefringence effects by rotating the polarization state of the light beam using polarization rotation means, thereby maintaining measurement accuracy despite the altered polarization parameters introduced by the optical fiber

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If waveguide birefringence compensation is implemented, then measurement precision is improved, but device complexity is worsened

Engineering Contradiction:
Improvepolarization information accuracyVSAvoidoptical component configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Polarization rotation means are introduced as intermediary components that actively compensate for the birefringence effects of the optical fiber, restoring the polarization state to enable accurate measurements without requiring complex real-time correction systems

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses the optical fiber's own transmitted light, after appropriate polarization rotation, to perform the measurement, making the system self-contained and eliminating the need for additional complex external correction equipment

Inventive Principle:
Principle #25Self-service

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

Enables the analysis of biological tissues in vivo and in situ without biopsy, providing detailed polarization information for medical and microelectronic applications.

Implementation Method 1

at least one waveguide (6) suitable for being traversed by an incident beam and by a beam reflected by the target sample (8)

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

polarization rotation means suitable for rotating two orthogonal polarimetric components E∥I

Methodology Applied
Scientific EffectFaraday effect: Faraday Effect

Implementation Method 3

steps c) and e) compensate for the effect of the birefringence of the waveguide

Methodology Applied
Scientific EffectBirefringence: Birefringence

Implementation Method 4

photodetectors to calculate polarization information

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP2376882B1Device and method for determining a piece of polarisation information and polarimetric imaging device
Publication Date: 2021.08.11 CENT NAT DE LA RECH SCI (C N R S)
  • EP2376882B1 patent drawingFigure 1~3
  • EP2376882B1 patent drawingFigure 2~6
  • EP2376882B1 patent drawingFigure 4~5

AI summary

The invention relates to a method and to a device (2) for determining at least one piece of polarisation information on a measurement point of a target sample (8), the device (2) comprising: - a light source (4) capable of emitting a rectilinearly polarised light beam, the light beam being intended to be reflected by the measurement point; - a means (9) for computing polarisation information on the measurement point using the beam reflected by the target sample (8); - at least one waveguide (6) for guiding the incident beam towards the target sample (8) and the reflected beam towards the computing means (9); and - a means (22) for rotating the polarisation, capable of rotating two orthogonal polarimetric components of the incident beam after passing through the waveguide and two orthogonal polarimetric components of the reflected beam before passing through the waveguide.