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Low noise 3 × 3 coupler demodulation scheme based on spectral subtraction with multi-window minimum statistical noise
Optics Express
|November 22, 2024
Summary
This study introduces spectral subtraction to reduce noise in fiber-optic sensing systems. The method significantly lowers the noise floor, enhancing sensing accuracy without extra hardware.
Area of Science:
- Optics
- Signal Processing
- Fiber Optic Sensors
Background:
- Interferometric fiber-optic sensing systems are crucial for precise measurements.
- 3x3 coupler demodulation techniques can be susceptible to noise, limiting performance.
- Reducing the noise floor is essential for improving the sensitivity and accuracy of these systems.
Purpose of the Study:
- To propose and validate a novel noise reduction technique for interferometric fiber-optic sensing systems.
- To enhance the signal-to-noise ratio (SNR) in systems employing 3x3 coupler demodulation.
- To improve the overall feasibility and cost-effectiveness of fiber-optic sensing applications.
Main Methods:
- Implementation of spectral subtraction utilizing multi-window minimum statistical noise estimation.
- Processing of two interference signals to estimate and remove noise spectra.
- Application of ellipse fitting and arctangent algorithms for subsequent signal demodulation.
Main Results:
- Significant reduction in the system's noise floor, averaging 25 dB in the 0-5 kHz range.
- Maximum noise floor reduction of 30 dB achieved at 50 kHz, reaching 0.7 µrad/√Hz.
- Demonstrated noise reduction without the need for additional optical components.
Conclusions:
- The proposed spectral subtraction method effectively reduces noise in interferometric fiber-optic sensing systems.
- The technique enhances system performance and accuracy without increasing complexity or cost.
- This approach improves the practicality of fiber-optic sensing in diverse environmental conditions.
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