Positive and negative slope-assisted BOTDA based on five-frequency light to compensate for the effect of loss and reflection

Slope assisted Brillouin optical time domain analysis (SA-BOTDA) with a linear slope was realized by using five-frequency pump and probe lights, where the sign of the slope was changed by controlling the optical power of each frequency component for the multi-frequency pump and probe. By employing both negative and positive linear slopes in the SA-BOTDA, we compensated for the effects of optical loss and Fresnel reflection at a mechanical connector.