Influence of the Laser Frequency Drift in Phase-Sensitive Optical Time Domain Reflectometry

Zhirnov, A. A.; Stepanov, K. V.; Chernutsky, Anton O.; Fedorov, Aleksey K.; Nesterov, Evgeniy; Svelto, C.; Pnev, Alexey B.; Karasik, Valeriy E.

doi:10.1134/s0030400x1910031x

Cited by 17 publications

(9 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A second type of DAS noise characterized by a random infinite‐velocity spike is attributed to laser frequency drift or laser noise (Zhirnov et al, ). This source of optical noise should be ameliorated over time as laser quality increases and can also be removed with a median filter.…”

Section: The Das Measurement Principlementioning

confidence: 99%

On the Broadband Instrument Response of Fiber‐Optic DAS Arrays

2020

View full text Add to dashboard Cite

Distributed Acoustic Sensing (DAS) is a novel tool in array seismology that measures the phase of backscattered laser pulses traveling in a fiber‐optic cable, and relates this measurement to the axial strain induced on the cable by a propagating seismic wavefield. Combining DAS with telecommunications optical fiber networks has begun to address a range of earth science questions where cost and field logistics have historically hindered observations. Unlike classic inertial seismometers, DAS instrument response is presently unquantified. This topic includes a variable sensing element—the fiber, including packaging and installation—which changes between experiments. Ignoring this element, one DAS record should approximate a fixed‐length strain gauge, which exactly measures Earth's motion down to quasi‐static frequencies relevant to geodesy. In this paper, we test this hypothesis using seismological observations of teleseismic earthquakes and microseism noise spanning the 1 to 120 s period range. We use a commercial DAS interrogator unit connected to an optical fiber previously used for telecommunication and a colocated broadband seismometer to estimate the DAS transfer function. We find a 1:1 correspondence with actual ground motion from 10–120 s. At shorter periods (1–10 s), DAS amplitude response is enhanced by 3–11 dB. Phase response is flat over this range of periods. We interpret the recovered DAS response function in terms of hypothesized fiber coupling and photonic effects. We propose this calibration methodology for future DAS experiments where seismic amplitude information is desired.

show abstract

Section: The Das Measurement Principlementioning

confidence: 99%

On the Broadband Instrument Response of Fiber‐Optic DAS Arrays

2020

View full text Add to dashboard Cite

show abstract

“…This setup is very similar to a standard telecommunication OTDR, but an ultra-narrow line-width laser source is necessary. 2,6,9 This technique is called Φ-OTDR because it detects phase changes along the fiber. The spatial resolution of two close events is dependent on the pulse duration.…”

Section: Dvb-t/t2mentioning

confidence: 99%

Influence of phase-sensitive optical time-domain reflectometer on community antenna television transmission

et al. 2021

View full text Add to dashboard Cite

Multiple studies have been carried out to analyze the mutual interaction of a phasesensitive optical time-domain reflectometer (Φ-OTDR) and parallel digital data traffic. However, interactions with analog transmission, e.g., community antenna television (CATV), have not been addressed. Our study examines and presents the influence of a developed sensing system Φ-OTDR when operated simultaneously on parallel fibers with the transfer of data from an analog CATV system. Three scenarios are suggested and discussed for the measurements and optimization of the data network in the analog CATV data transfer. These scenarios are suggested to enable the verification of the mutual interactions between data networks with the analog data transfer and suggested sensing system and to determine how the data network with the analog data transfer may or may not be influenced by the sensing system. The optimization and measurements prove that the analog CATV data transfer was negatively influenced by the sensing system Φ-OTDR, and the channel bit error rate increased by nearly half. The implementation of the sensing system Φ-OTDR was realized for a data network, followed by the testing and optimization, which proved that the safe spectral distance between the CATV and the sensing system is 150 GHz and higher. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

“…As mentioned above, the main components generating noise in this system are laser wavelength instability, optical preamplifier noise, and photodetector module noise. A detailed analysis of the influences of instability in the laser source’s radiation is given in [ 18 , 56 ]. They can only be eliminated when using an ideal laser source or a source with negligible frequency fluctuations.…”

Section: Calculationmentioning

confidence: 99%

“…Scientists from Spain, led by H.F. Martins, worked on various aspects of the system’s operation, including implementing them, increasing the sensor length using Raman amplifiers, and measuring temperature using chirped pulses [ 9 , 10 , 11 , 12 ]. In Russia, several scientific groups are also engaged in this issue, with particular attention to the device’s principles and limitations, the possibilities of using it as a temperature sensor, and the development of principles for restoring the phase of the recorded signal [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Many results have found practical applications in commercial systems, including in the oil and gas industry [ 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

The Sensitivity Improvement Characterization of Distributed Strain Sensors Due to Weak Fiber Bragg Gratings

Stepanov

Zhirnov

Chernutsky

et al. 2020

Sensors

View full text Add to dashboard Cite

Weak fiber Bragg gratings (WFBGs) in a phase-sensitive optical time-domain reflectometer (phi-OTDR) sensor offer opportunities to significantly improve the signal-to-noise ratio (SNR) and sensitivity of the device. Here, we demonstrate the process of the signal and noise components’ formation in the device reflectograms for a Rayleigh scattering phi-OTDR and a WFBG-based OTDR. We theoretically calculated the increase in SNR when using the same optical and electrical components under the same external impacts for both setups. The obtained values are confirmed on experimental installations, demonstrating an improvement in the SNR by about 19 dB at frequencies of 20, 100, and 400 Hz. In this way, the minimum recorded impact (at the threshold SNR = 10) can be reduced from 100 nm per 20 m of fiber to less than 5 nm per 20 m of fiber sensor.

show abstract

Influence of the Laser Frequency Drift in Phase-Sensitive Optical Time Domain Reflectometry

Cited by 17 publications

References 22 publications

On the Broadband Instrument Response of Fiber‐Optic DAS Arrays

On the Broadband Instrument Response of Fiber‐Optic DAS Arrays

Influence of phase-sensitive optical time-domain reflectometer on community antenna television transmission

The Sensitivity Improvement Characterization of Distributed Strain Sensors Due to Weak Fiber Bragg Gratings

Contact Info

Product

Resources

About