RESUMO
In this work, an interferometric sensor has been interrogated 290 km away from the monitoring station, reaching the longest distance in fiber optic sensing up to date. This has been attained by employing a double-pumped random distributed feedback fiber laser as the light source for a fiber optic low-coherence interferometry scheme. Additionally, the capability of the system to achieve coherence multiplexing for ultra-long range measurements (up to 270 km) has been proved, without presenting crosstalk between the sensors. The use of coherence multiplexing together with a random distributed feedback fiber laser addresses two of the main limitations of long-range sensing setups: their limited multiplexing capability and the need to reach the maximum monitoring distance.
RESUMO
A real-time switchable and reconfigurable multiwavelength laser has been experimentally carried out. The laser cavity is based on a random distributed mirror and a novel real-time reconfigurable filter mirror structure. The proposed laser has been demonstrated to generate any combination of wavelengths at the 50 and 100 GHz International Telecommunications Union (ITU) grids specifications. By simultaneously using Er-doped fiber and Raman amplification, a 15 nm wide lasing window at the C band can be utilized to create up to 18 different lasing wavelengths into the ITU grid that can be switched automatically and in real time when desired.