Hybrid Golay-coded Brillouin optical time-domain analysis based on differential pulses

Area of Science:

• Photonics and Optical Sensing
• Signal Processing in Optical Systems
• Fiber Optic Sensing Technologies

Background:

• Brillouin optical time-domain analysis (BOTDA) is crucial for fiber optic sensing.
• Differential pulse pair (DPP) methods offer high spatial resolution.
• Unipolar Golay coding is an advanced technique for improving BOTDA performance.

Purpose of the Study:

• To investigate unipolar Golay coding implementations in DPP-based BOTDA.
• To introduce a novel hybrid Golay-DPP coding scheme.
• To enhance signal-to-noise ratio (SNR) and reduce measurement time in BOTDA.

Main Methods:

• Implementation of different unipolar Golay coding approaches with DPP.
• Development and application of dedicated post-processing techniques.
• Proposal and experimental validation of a hybrid Golay-DPP coding scheme.

Main Results:

• Dedicated post-processing is essential for maintaining DPP's spatial resolution.
• The hybrid Golay-DPP scheme achieved a 1.5 dB SNR improvement.
• Measurement time was halved, resulting in a 3 dB overall coding gain.
• Experimental validation demonstrated 50 cm spatial resolution over 10.164 km with 1.4 MHz frequency uncertainty.

Conclusions:

• The proposed hybrid Golay-DPP coding scheme significantly enhances BOTDA performance.
• This technique offers a practical solution for faster and more accurate fiber optic sensing.
• The findings pave the way for advanced applications in distributed fiber sensing.