Interferometer Interrogation System Using Modulated Optical Signals
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Solution Overview
Problem
Interferometers face accuracy and precision issues due to imperfections in optical components and environmental changes, and existing solutions like active interferometry may be costly and unsuitable for all applications, particularly current sensing.
Innovation Solution
A system for interrogating an interferometer that generates multiple optical signals with different modulation parameters, using optical couplers, photodetectors, and an electronic processor to determine optical phase shifts by measuring ingress and egress optical powers and applying correction factors to account for system losses, allowing for precise measurements with passive techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If passive interferometry is used, then cost is reduced, but measurement accuracy and precision deteriorate due to system losses and imperfections in optical components
Solution Approach 1:
The patent implements feedback by measuring the actual fractional power distribution at each optical port using photodetectors and processing systems, then using these measurements to calculate correction factors that compensate for system losses and component imperfections, thereby restoring measurement accuracy in passive interferometry
Solution Approach 2:
The patent changes the parameter being measured from raw optical power to correction factors derived from fractional power distribution measurements. By measuring the actual power distribution at each port and calculating correction factors, the system compensates for losses and imperfections, enabling accurate measurements with passive, inexpensive components
2Measurement precision
If active interferometry is used, then measurement accuracy is improved, but cost increases and suitability for certain applications deteriorates
Solution Approach 1:
The patent uses feedback measurements of fractional power distribution to calculate correction factors that enable passive interferometry to achieve accuracy comparable to active interferometry, eliminating the need for expensive active components while maintaining measurement precision
Solution Approach 2:
The patent replaces expensive active interferometer components with inexpensive passive components, using cost-effective photodetectors and processing systems to achieve accurate measurements through correction factor calculations, making the system suitable for applications like current sensing where active interferometry is unsuitable
3Productivity
If fast pulsed optical sources are used, then measurement speed is improved, but cost increases and maintenance requirements increase
Solution Approach 1:
The patent uses continuous wave (CW) optical sources instead of fast pulsed sources, maintaining continuous measurement capability through correction factor calculations. The system achieves high measurement rates by continuously monitoring fractional power distribution and calculating corrections, eliminating the need for expensive pulsed sources while maintaining productivity
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 accurate and precise measurements at high rates using inexpensive components, with calibration rates matching environmental changes, suitable for applications like electrical current sensing and rotation measurement.
Implementation Method 1
The optical phase shift is experienced by at least one of a plurality of light waves within the interferometer and which may be superimposed external of the interferometer so they interfere
Implementation Method 2
The superimposed plurality of light waves may be detected with a light detector to generate at least one electrical signal
Data Source
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AI summary
Disclosed herein is a system (10) for interrogating an interferometer. The system (10) comprises an optical signals generation system (14) for concurrently generating a plurality of optical signals that each have a modulation parameter that the other of the plurality of optical signals d not have. The optical signals generation system (14) is for optically coupling each of the plurality of optical signals to a plurality of optical ports (16, 18, 20) of the interferometer (12) for ingress of the plurality of optical signals into the interferometer (12). The system (10) comprises an interferometer output processing system (22). Also disclosed herein is an interferometric system and a method for interrogating an interferometer