Spatial resolution improvement of single-shot digital optical frequency comb-based Brillouin optical time domain analysis utilizing multiple pump pulses.

A spatial resolution improvement scheme for the digital optical frequency comb (DOFC)-based single-shot Brillouin optical time domain analysis (BOTDA) by utilizing multiple pump pulses is demonstrated. Assisted by four pump pulses, the spatial resolution can be improved by four times without decreasing the detection resolution. The response time, and the spatial resolution of our scheme over 10 km fiber, are 0.1 ms and 12.5 m. Distributed temperature and strain measurements are carried out with detection resolutions of 1.6°C and 44  μϵ, respectively, and the capability of dynamic measurement of this proposed BOTDA is also demonstrated by probing a vibration with frequency up to 1.2 kHz.