研究目的
Investigating the distributed Brillouin analysis of an 8.8-km-long fiber with a spatial resolution of 2 cm, addressing all 440 000 potential resolution points, and identifying a 7-cm-long hot-spot.
研究成果
The work reported a distributed Brillouin sensor experiment over 8.8 km of fiber with a 2 cm resolution, addressing all 440 000 potential resolution points. The measurement was based on dual-hierarchy modulation of the optical waves, inspired by the analogy between distributed fiber sensors and radar systems. The limitations were examined in large-scale numerical simulations, highlighting the fundamental differences between the mathematically perfect correlation properties of the codes involved and their physical representation in SBS. The figure of merit of the current experiment is 0.08 m?1, eight times better than previous work, enabled primarily by the introduction of a longer, improved amplitude modulation sequence.
研究不足
The main drawback is the large number of correlation peak position scans necessary to reconstruct the gain spectra along the entire fiber. The system also requires a long fiber delay for scanning correlation peak positions, and the duration of the experiment was several hours.
1：Experimental Design and Method Selection:
The methodology involves the simultaneous generation and analysis of Brillouin interaction in more than 2000 correlation peaks, induced by periodic phase modulation of the pump and signal waves. The Brillouin amplifications at individual peaks are resolved using radar-like coding of pump wave magnitude by a 10000 bit-long aperiodic sequence, and postdetection compression at the receiver end.
2：Sample Selection and Data Sources:
An
3：8-km-long fiber was used as the sample. List of Experimental Equipment and Materials:
The setup included a laser diode source, electro-optic phase modulator, arbitrary waveform generator, single-sideband EO modulator, EDFA, and a photo-detector.
4：Experimental Procedures and Operational Workflow:
Light from a laser diode was phase-modulated and split into pump and signal branches. The pump was amplitude-modulated and amplified before being launched into the fiber. The signal was delayed, polarization-scrambled, and launched into the opposite end of the fiber. The output signal was detected and analyzed.
5：Data Analysis Methods:
The output signal was cross-correlated with a reference sequence using offline digital processing.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
