Compensation of phase noise impairments in distributed acoustic sensors based on optical pulse compression time-domain reflectometry

Autor: Enrique Piñeiro, Mikel Sagues, Alayn Loayssa
Přispěvatelé: Universidad Pública de Navarra. Departamento de Ingeniería Eléctrica, Electrónica y de Comunicación, Nafarroako Unibertsitate Publikoa. Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza Saila, Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa. Institute of Smart Cities - ISC
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Popis: We introduce a method to compensate for the deleterious effects of the phase noise of the laser source on long-range distributed acoustic sensors (DAS) that implement optical pulse compression (OPC). Pulse compression can be used in coherent optical time-domain reflectometry (COTDR) sensors to extend the measurement range without compromising spatial resolution. In fact, OPC-COTDR sensors have demonstrated the longest measurement range to date in passive sensing links that do not require distributed amplification to compensate fiber attenuation. However, it has been found that the limited coherence of the laser source has a degrading effect on the actual performance enhancement that pulse compression can bring because it constrains the maximum duration of the compression waveforms that can be used and makes the use of lasers with extremely low phase noise necessary.We introduce a technique to compensate for the effects of phase noise on OPC-COTDR sensors so that they can demonstrate their full potential for long-range measurements using lasers with less stringent phase noise requirements. The method is based on sampling the phase noise of the laser with an auxiliary interferometer and using this information in a simple signal processing technique to mitigate its deleterious effect on the signal measured. We test our method in an OPCCOTDR sensor that uses 500-μs linear frequency modulated pulses to demonstrate 100-km range measurements with 200 p/√Hz of strain sensitivity at 2-m initial spatial resolution that becomes 10-m after applying the gauge length. To our knowledge, this is the longest compression waveform demonstrated to date in an OPCCOTDR sensor. Its use provides an extra 20-km range compared to previous demonstrations using laser sources of comparable linewidth. Furthermore, comparable performance is also demonstrated when using a laser source with an order of magnitude larger linewidth. This work was supported in part by European Union “Next generationEU”/PRTR and MCIN/AEI/10.13039/501100011033 under grant PDC2021-121172-C21, in part by FEDER “A way to make Europe” and MCIN/AEI/10.13039/501100011033 under Grant PID2019-107270RB-C22, and in part by the Gobierno de Navarra under Grant PC210-211 FIBRATRAFIC.
Databáze: OpenAIRE