Optics and Photonics Society of Iran

In order to monitor the structural health of an aircraft, sensing method with millimeter spatial resolution is required. Brillouin-based optical fiber sensors often suffer from a tradeoff between their spatial resolution enhancement and their dynamic range. In this paper a new method is proposed that can achieve a mm-order spatial resolution in distributed fiber optic sensors with a dynamic range as long as several tens of kilometers. As an added advantage, this method has a shorter measurement time. The principle of the proposed technique is based on the accumulation of acoustic phonons which are stimulated due to the passage of successive pico-second pulses along the sensing fiber.