DBA-Based BOTDA Using Optical Comb Pump and Pulse Coding With a Single Laser

We proposed and demonstrated a new structure, which employs a single laser in Brillouin optical time-domain analysis sensor assisted by distributed Brillouin amplification. This structure can avoid the stability problem caused by laser frequency drift. In addition, we used an optical comb technique to suppress the distortion of pump pulse. Moreover, the feasibility of an optical pulse coding technology in this system was studied. In particular, we explored the influence of coding parameters on the transient gain saturation of the coded pulse. Results show that the coded pulse space and coding length must be optimized to suppress its transient gain saturation, by which the sensing with lower decoding error can be achieved.