Interferometric Measurement of 3D Translation on Diffuse Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing interferometric methods face challenges in accurately measuring two or three-dimensional translations of objects with diffusely reflective surfaces, as they often require specific orientations and struggle with noise from perpendicular translation components.
Innovation Solution
The use of a plurality of interferometers with single mode fibers and collimators to direct collimated beams non-orthogonally at diffusely reflective surfaces, allowing for the measurement of translation components in different directions without the need for specific surface orientations, and filtering out noise from perpendicular translations using a combination of single mode fibers and collimators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional interferometry is used with diffusely reflective surfaces, then measurement capability is limited to qualitative information, but measurement precision deteriorates
Solution Approach 1:
The patent segments the optical measurement system into multiple independent interferometers, each equipped with a single-mode fiber and collimator combination. This segmentation allows each interferometer to independently measure translation components along specific directions, transforming the qualitative speckle pattern measurement into quantitative interferometric measurements with high precision.
Solution Approach 2:
The patent introduces a new dimension to the measurement capability by using multiple interferometers oriented at different angles. Each interferometer measures translation along its beam direction, and by combining measurements from multiple dimensions (different angles), the system achieves accurate 2D or 3D translation measurement that is independent of surface orientation.
2Adaptability or versatility
If multiple interferometers are used to measure translation components in different directions, then measurement capability improves, but device complexity increases
Solution Approach 1:
The patent creates a universal measurement module consisting of a single-mode fiber coupled with a collimator that can be oriented at different angles. This universal module can measure translation components along any desired direction, and multiple instances of this module work together to provide comprehensive 2D or 3D measurement capability without requiring fundamentally different measurement approaches for each direction.
Solution Approach 2:
The patent merges the functions of multiple interferometers into a coordinated measurement system where each interferometer measures a specific translation component. By combining the measurements from multiple interferometers that are synchronized and calibrated, the system achieves comprehensive translation measurement while managing complexity through functional integration.
3Adaptability or versatility
If beams are directed non-orthogonally at diffusely reflective surfaces, then independence from surface orientation is achieved, but noise from perpendicular translation components increases
Solution Approach 1:
The patent segments the measurement task into multiple independent interferometers, each sensitive to translation along its beam direction. By orienting beams at non-orthogonal angles to the surface, each interferometer independently measures the translation component along its direction, and the combined measurements provide information that is independent of the surface orientation while filtering out perpendicular translation noise through geometric arrangement.
4Measurement precision
If single mode fibers and collimators are used to filter noise, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent applies preliminary noise filtering by using single-mode fibers and collimators before the interferometric measurement process. The single-mode fiber acts as a spatial filter that selects only the fundamental mode, and the collimator ensures proper beam collimation. This preliminary conditioning of the light beam reduces noise from perpendicular translation components and improves measurement precision before the actual interferometric measurement takes place.
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 approach enables accurate and noise-reduced interferometric measurement of 2D or 3D translations, independent of the surface orientation relative to the beam direction, allowing for simultaneous measurement of translation components in various directions from a single surface part, even with limited access.
Implementation Method 1
a single mode fiber and a collimator configured to transmit the outgoing light to the object successively through the single mode fiber and the collimator
Implementation Method 2
to collect reflection into the single mode fiber with the collimator
Implementation Method 3
measuring a time dependent phase variation of the light that has travelled over the variable distance, usually from periodic intensity variation of the mixed signal in the interferometer
Implementation Method 4
direct a collimated expanded beam of the outgoing light non-orthogonally at a diffusely reflective surface part of the object
Data Source
AI summary
Translations of an object in a plurality of different spatial directions are measured using a plurality of interferometers to detect interference with light that has been reflected from a diffusively reflective surface, preferably using diffuse reflection from the same planar surface to measure in each of the different spatial directions. At least the interferometers that measure translation in directions that are not perpendicular to the surface each comprises a single mode fiber and a collimator configured to transmit the outgoing light to the object successively through the single mode fiber and the collimator, and to collect reflection into the single mode fiber with the collimator both along a same beam direction. It has been found that, when reflection of a beam with a beam direction at an oblique angle to a diffusively reflective surface is used, the interference resulting from translation of the object is due substantially only to translation in the beam direction.