Cost-Effective Brillouin Optical Time-Domain Analysis Sensor Using a Single Optical Source and Passive Optical Filtering

Abstract

We present a simplified configuration for distributed Brillouin optical time-domain analysis sensors that aims to reduce the cost of the sensor by reducing the number of components required for the generation of the two optical waves involved in the sensing process. The technique is based on obtaining the pump and probe waves by passive optical filtering of the spectral components generated in a single optical source that is driven by a pulsed RF signal. The optical source is a compact laser with integrated electroabsorption modulator and the optical filters are based on fiber Bragg gratings. Proof-of-concept experiments demonstrate 1 m spatial resolution over a 20 km sensing fiber with a 0.9 MHz precision in the measurement of the Brillouin frequency shift, a performance similar to that of much more complex setups. Furthermore, we discuss the factors limiting the sensor performance, which are basically related to residual spectral components in the filtering process.

Zuntz optikoan oinarritutako sentsoreen prestazioen muga-efektu berria, egituren egoera monitorizatzea helburu

“…Testuinguru honetan, aunitz dira BOTDA sentsoreen gaitasunak zabaltzeko lanetan diharduten ikerkuntza talde eta korporazioak. Duten neurketa bereizmena hobetzen (Floch et al, 2015a), sistemaren sinplifikazioa bilatzen (Iribas et al, 2016) edo luzera handiagoetarako neurketak lortzeko prestatzen (Floch et al, 2015b) besteak beste.…”

“…Bestalde, BOTDA sistemaren sinplifikazioa eta hortaz prezioaren merkatzea bilatze aldera, hainbat dira aurkitzen ahal diren ekarpenak. DFB laser merkeak erabiliz injekzio-blokeo bidez pultsua zein uhinjarraia sortzen dituzten eskemak erabiltzea (Thevenaz et al, 2004), edo seinale optiko guztiak iturri optiko bakar batez sortzean dautzatenak (Iribas et al, 2016).…”

Application of Dual-Frequency Self-Injection Locked DFB Laser for Brillouin Optical Time Domain Analysis

“…A number of new BOTDA solutions have been proposed. Among them are sensors employing a single optical source driven by pulsed RF signals and passive optical filtering [ 23 ], systems based on time-division pump-probe generation by direct modulation of a laser diode through an arbitrary waveform generator [ 24 ], and sources that use the Stokes wave generated inside a highly nonlinear fiber [ 25 ]. The idea to use a Brillouin fiber laser has been raised and investigated for this purpose [ 26 , 27 , 28 ].…”

BOTDA Sensing Employing a Modified Brillouin Fiber Laser Probe Source

“…On the other hand, OSB technique requires wide bandwidth EOM and up-to 10 GHz-electrical signal generator. Furthermore, the [9], systems based on time-division pump-probe generation by direct modulation of a laser diode through a arbitrary waveform generator [10] and sources which use the Stokes wave generated inside a highly nonlinear fiber (HNF) to generate the probe wave [11].…”