Interferometer Phase-Error Correction via OxPaDE Scaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fourier-Transform interferometers experience signal degradation due to differences between induced and actual path differences in high étendue light, leading to reduced sensitivity and longer analysis times, especially when analyzing non-homogenous samples.
Innovation Solution
A method involving a detector array that calculates an Off-Axis Path Difference (OxPaDE) scaling function for each light channel, coordinate-transforms the Raw Location-Specific Signals, and averages them to produce a Combined Signal, which is then inverse Fourier-Transformed to reduce phase-error signal degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the detector aperture size is increased to capture more light and improve analysis speed, then the productivity and sensitivity are improved, but the signal degradation due to off-axis path differences increases
Solution Approach 1:
The patent segments the detector array into multiple regions, each corresponding to different off-axis angles. By processing signals from different detector regions separately and applying appropriate path difference corrections to each segment, the system can handle large aperture sizes while maintaining signal accuracy for each angular component.
Solution Approach 2:
The patent applies location-specific path difference scaling functions to different regions of the detector array. Each detector location receives a customized correction based on its specific off-axis angle, allowing the system to maintain high measurement precision across the entire large aperture detector while capturing maximum light.
2Measurement precision
If the scan range is increased to improve the spectral resolution and analysis capability, then the measurement precision is improved, but the signal degradation due to accumulated path differences increases
Solution Approach 1:
The patent applies path difference scaling corrections to the interferogram data before performing the Fourier transform. By pre-correcting the path differences for each detector location based on the known off-axis angles and scan range, the system maintains signal quality throughout the extended scan range while achieving high spectral resolution.
3Productivity
If a larger detector aperture is used to analyze non-homogenous samples more efficiently, then the productivity is improved, but the phase-error signal degradation increases
Solution Approach 1:
The patent implements a feedback mechanism where the known geometry of the interferometer and detector array is used to calculate and apply appropriate path difference corrections to each detector element. This feedback loop compensates for the phase errors introduced by large aperture angles, maintaining spectral accuracy while enabling efficient analysis of non-homogenous samples across the entire aperture.
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 enhances the sensitivity of Fourier-Transform interferometers by correcting for path differences, allowing for faster and more accurate analysis of non-homogenous samples without compromising detector aperture or scan range.
Implementation Method 1
This induced path difference causes the two coherent waves to interfere with one another to a degree based upon the amount of path difference that is induced
Data Source
AI summary
The present invention relates to a method of reducing phase-error signal degradation in a characteristic spectrum produced by a Fourier Transform interferometer, comprising the steps of: (1) Receiving, upon the detector array, a light beam comprised of a plurality of light channels, each of the light channels being received at a corresponding location upon the detector array; (II) Producing, for each corresponding location, a Raw Location-Specific Signal (LSS) from the received light channels; (III) for each Raw LSS, calculating an Off-Axis Path Difference (OxPaDE) scaling function dependent upon a distance and direction of the corresponding location from a target location; (IV) coordinate-transforming each Raw LSS using their corresponding calculated OxPaDE function to produce an Adjusted LSS; (V) averaging each Adjusted LSS to produce a Combined Signal; and (VI) inverse Fourier-Transforming the Combined Signal to produce the characteristic spectrum of the received light beam as a function of wavenumber.