Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Accurate Determination of Brillouin Frequency in Brillouin Distributed Fiber Sensors using Cross Recurrence Plot Analysis
Categories for this Invention
Category – Fiber Optic Sensing
Applications – Structural Health Monitoring,
Power Grid & Geotechnical Monitoring
Industry- Telecommunications, Energy and Utilities, structural monitoring
Market – Global Fiber Optic Sensors Market to Reach $605.4 Million by 2032 with a CAGR of 6.2%
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Problem Statement
- Conventional distributed Brillouin sensors face accuracy limitations due to very low signal-to-noise ratios (SNR), especially at the farther end of the sensing fiber.
- Standard methods like quadratic fitting are error-prone with low SNR signals, leading to inaccuracies in Brillouin frequency shift (BFS) estimation.
- Existing techniques need enhancement to accurately measure BFS over long distances with low SNR, with cross-correlation methods showing promise for improving measurement accuracy.
Technology
- Brillouin Scattering and Frequency Shift Measurement: The process involves initiating Brillouin scattering in an optical fiber by propagating an intense optical signal, generating backscattered light with a frequency shift indicative of local acoustic velocity.
- Cross Recurrence Plot Analysis (CRPA): The method uses CRPA to compute the Brillouin frequency at various locations along the sensing fiber by comparing a reference spectrum (Lorentzian, Gaussian, or Voigt lineshape) with the measured spectrum. This technique enhances the accuracy of frequency measurement even with low signal-to-noise ratios (SNR <10 dB).
- Enhanced Measurement Accuracy: The process is designed to work effectively with distorted Brillouin gain spectra and uses frequency steps greater than 1 MHz.
Key Features / Value Proposition
Enhanced Accuracy:
- Utilizes Cross Recurrence Plot Analysis (CRPA) to accurately measure Brillouin frequency shifts, improving precision even in low signal-to-noise ratio conditions.
High Sensitivity:
- Capable of detecting small changes in temperature and strain with high sensitivity by analyzing the Brillouin gain spectrum.
Robust Performance:
- Effective in environments with distorted Brillouin gain spectra, maintaining reliable measurements under challenging conditions.
Flexible Spectrum Analysis:
- Supports various reference spectrum types (Lorentzian, Gaussian, Voigt), providing versatility in different sensing applications.
Large-Scale Monitoring:
- Suitable for distributed sensing along extensive optical fiber lengths, enabling comprehensive monitoring of large infrastructures.
Advanced Data Processing:
- Employs advanced signal processing techniques to handle low SNR measurements, enhancing the overall performance and accuracy of Brillouin distributed sensors.
Questions about this Technology?
Contact For Licensing
sm-marketing@imail.iitm.ac.in
ipoffice2@iitm.ac.in
Research Lab
Prof. Balaji Srinivasan
Department of Electrical Engineering
Intellectual Property
- IITM IDF Ref. 1545
- IN 379844 – Patent Granted
Technology Readiness Level
TRL – 5
Technology validated in relevant environment.