Brillouin optical time-domain analyzer engineered implementation using high-order polynomial spectral fitting

This work reports on the development and implementation of a first BOTDA (Brillouin optical time-domain analysis) sensing/detection platform in Bucharest, Romania. Our setup enables us to quantitatively determine temperature and strain in a few dozen kilometers long optical fibers. The engineered implementation uses a semiconductor optical amplifier to secure enhanced sensing performance, instead of using the more common electro-optical modulators employed to generate defined few nanosecond-long light pulses. In addition, we show that higher-order polynomial peak fitting can perform faster than Gaussian fitting and can provide a novel processing approach to extract the measuring information when the optical fiber exhibits more than a single Brillouin gain spectral peak. Our home-built and processing user interface. We demonstrate quantitative temperature measurements by using the engineered platform over a sensing/detection distance of 24 km with 2 m spatial resolution.