Abstract:
The influence of the laser frequency drift on the operation of phase-sensitive optical time domain reflectometry ($\varphi$-OTDR) systems is considered. Theoretical results based on a new numerical $\varphi$-OTDR model demonstrating the influence of the laser frequency instability on a signal are reported. This model is verified based on experimental data. It has been used to calculate the signal-to-noise ratio (SNR) of the system for different parameters of the laser source stability. As a result, quantitative requirements for lasers used in $\varphi$-OTDR systems are formulated.
Keywords:
phase-sensitive optical time domain reflectometer, laser frequency fluctuation, narrow-band laser, distributed sensor.
A theoretical and experimental study of the stability of a laser source was performed by A.A. Zhirnov and K.V. Stepanov and funded by the Russian Foundation for Basic Research, project no. 18-32-00688. A.K. Fedorov was funded by the Russian Foundation for Basic Research, project no. 18-37-20033.
Citation:
A. A. Zhirnov, K. V. Stepanov, A. O. Chernutsky, A. K. Fedorov, E. T. Nesterov, C. Svelto, A. B. Pnev, V. E. Karasik, “Influence of the laser frequency drift in phase-sensitive optical time domain reflectometry”, Optics and Spectroscopy, 127:4 (2019), 603–610; Optics and Spectroscopy, 127:4 (2019), 656–663