N. I. Kalmykov, D. A. Kovalenko, I. A. Lobach, S. I. Kablukov, “Reflectogram shape deformation in distributed fibre systems in the presence of spontaneous noise in the probe radiation”, Kvantovaya Elektronika, 2021, Volume 51, Number 12,Pages <nobr>1107

Selection of reports presented at the 8th All-Russian conference on fibre optics (5-8 October 2021, Perm) (compiled and edited by S.L.Semjonov)

Reflectogram shape deformation in distributed fibre systems in the presence of spontaneous noise in the probe radiation

N. I. Kalmykov^a, D. A. Kovalenko^b, I. A. Lobach^a, S. I. Kablukov^a

^a Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk
^b SibSensor LLC, Novosibirsk

Abstract: We report a study of the effect of spontaneous emissioninduced noise in probe pulsed radiation on the reflectogram shape deformation in a distributed temperature sensor based on Raman scattering of light. Since the fraction of spontaneous emission in the used erbium-doped amplifier can reach 50% of the total power, this leads to deviations of reflectograms in the temperature sensor from the theoretical exponential dependence and, as a result, can yield a temperature measurement error of several degrees. Filtering the radiation with an amplitude modulator makes it possible to reduce these deviations. The influence of spontaneous emission on reflectograms is studied theoretically and experimentally.

Keywords: distributed temperature sensor, Raman scattering of light, spontaneous emission, reflectogram, spectral filtering.

Received: 15.09.2021