Distributed optical fiber Brillouin sensors provide innovative solutions for the monitoring of temperature and strain in large structures. The effective range of these sensors is typically of the order of 20-30 km, which limits their use in certain applications in which the distance to monitor is larger. In this work, we have developed a new technique to significantly extend the measurement distance of a distributed Brillouin Optical Time-Domain Analysis (BOTDA) sensor. Distributed Raman Amplification in the sensing fiber provides the means to enhance the operating range of the setup. Three Raman pumping configurations are theoretically and experimentally investigated: co-propagating, counter-propagating and bidirectional propagation with respect to the Brillouin pump pulse. We show that some of the amplification schemes tested can extend the measurement range and improve the measurement quality over long distances.
Abstract. We present a new kind of broadband continuous-wave source which outperforms any other broadband superluminescent or amplified spontaneous emission source both in terms of output spectral density and bandwidth. Our source covers the wavelength band of interest for fiber applications (from 1450 to 1625 nm) and has an output power of approximately 1.3 W. The source is obtained by pumping a conventional nonzero dispersion-shifted fiber with a continuous-wave Raman fiber laser tuned to the region of small anomalous dispersion of the fiber. The laser beam undergoes an extreme spectral broadening in the fiber. Our experimental results show clearly that modulation instability (MI)-induced soliton fission is the key element leading to this spectral broadening. Modulation instability is seeded by fast intensity instabilities present in the laser output. We show that this source features a good power stability and we believe it might have very interesting applications in fiber sensing, for instance to avoid the need of amplification in the interrogation of remote Bragg gratings or to improve the resolution and dynamic range of optical coherence tomography setups.
This paper describes the design, characterization and calibration of a high power transfer standard for optical power measurements in optical fibres based on an integrating sphere radiometer. This radiometer, based on two detectors (Si and InGaAs), can measure powers between 100 nW and 10 W within the wavelength range of (400–1700) nm. The radiometer has been calibrated over the total spectral range of use against an electrically calibrated pyroelectric radiometer and different fibre laser diodes and ion lasers. The total uncertainty obtained is lower than ±1.5% for these wavelengths and power ranges (excluding the water absorption region).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.