Korbinain Königsbauer, A. Wosniok, N. Nöther, M. Schaller
We report on the development of a field-proven distributed fiber optic sensing system for structural health monitoring in road construction and civil engineering. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR) for distributed strain detection along a polymer optical fiber. In this method, the strain-induced backscatter increase in a graded-index multimode perfluorinated polymer optical fiber (PF-POF) is determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. This unit replaced an oversized vector network analyzer (VNA) usually used in the I-OFDR technique making the measurement system more robust and more suitable for its use in the field, whilst at the same time providing a significant reduction of the total sensor system costs. This paper presents a successful implementation of the entire sensor concept in a real construction project for the soil reinforcement and fiber optic monitoring of a road embankment using geosynthetics with incorporated PF-POF. The presented research includes development and installation in the field of the sensors integrated geosynthetics used for ground stabilization and additionally providing fiber optic POF-based monitoring function. The publication shows first measurement results of the further developed measurement method I-OFDR conducted along the PF-POF integrated in the geosynthetics embedded into a road embankment of the federal road B91 south from Leipzig.
{"title":"POF-based digital I-OFDR for strain detection in road construction","authors":"Korbinain Königsbauer, A. Wosniok, N. Nöther, M. Schaller","doi":"10.1117/12.2678436","DOIUrl":"https://doi.org/10.1117/12.2678436","url":null,"abstract":"We report on the development of a field-proven distributed fiber optic sensing system for structural health monitoring in road construction and civil engineering. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR) for distributed strain detection along a polymer optical fiber. In this method, the strain-induced backscatter increase in a graded-index multimode perfluorinated polymer optical fiber (PF-POF) is determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. This unit replaced an oversized vector network analyzer (VNA) usually used in the I-OFDR technique making the measurement system more robust and more suitable for its use in the field, whilst at the same time providing a significant reduction of the total sensor system costs. This paper presents a successful implementation of the entire sensor concept in a real construction project for the soil reinforcement and fiber optic monitoring of a road embankment using geosynthetics with incorporated PF-POF. The presented research includes development and installation in the field of the sensors integrated geosynthetics used for ground stabilization and additionally providing fiber optic POF-based monitoring function. The publication shows first measurement results of the further developed measurement method I-OFDR conducted along the PF-POF integrated in the geosynthetics embedded into a road embankment of the federal road B91 south from Leipzig.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129136940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Perrot, A. Morana, E. Marin, Y. Ouerdane, A. Boukenter, J. Bertrand, S. Girard
We investigate the performances accessible in terms of strain and temperature discrimination using Brillouin Optical Time Domain Analysis combined with the LEAF fiber from Corning, AllWave fiber (AW) from Lucent and TrueWave (TW) fiber from OFS when exposed to γ rays and X-rays up to 1 MGy(SiO2). All these fibers present a multipeak Brillouin Gain Spectrum (BGS) with unique dependencies of each of its peaks over temperature (T) and strain (ε). The evolution of their T and ε discrimination capability is investigated to evaluate how radiation affects the sensing performances. High dose irradiation changes the sensor performances through two main effects. First, the Radiation Induced Attenuation (RIA) limits the BGS amplitude, the sensing range and discrimination capability techniques relying on BGS amplitude. Second, radiations modify the Brillouin scattering properties by slightly changing the refractive indices and the acoustic velocities of the silica-based leading to small changes in T and ε dependencies and also to a limited Radiation Induced Brillouin Frequency Shift (RI-BFS) that causes a direct measurement error. Results exhibit an overall decrease of T and ε uncertainties through discrimination process after 1 MGy reaching 0.9°C and 29 με for 0.1 MHz frequency uncertainty for sensors based on the LEAF fiber.
{"title":"Radiation effects on Brillouin-based sensors: temperature and strain discrimination capability using telecom-grade optical fibers","authors":"J. Perrot, A. Morana, E. Marin, Y. Ouerdane, A. Boukenter, J. Bertrand, S. Girard","doi":"10.1117/12.2678636","DOIUrl":"https://doi.org/10.1117/12.2678636","url":null,"abstract":"We investigate the performances accessible in terms of strain and temperature discrimination using Brillouin Optical Time Domain Analysis combined with the LEAF fiber from Corning, AllWave fiber (AW) from Lucent and TrueWave (TW) fiber from OFS when exposed to γ rays and X-rays up to 1 MGy(SiO2). All these fibers present a multipeak Brillouin Gain Spectrum (BGS) with unique dependencies of each of its peaks over temperature (T) and strain (ε). The evolution of their T and ε discrimination capability is investigated to evaluate how radiation affects the sensing performances. High dose irradiation changes the sensor performances through two main effects. First, the Radiation Induced Attenuation (RIA) limits the BGS amplitude, the sensing range and discrimination capability techniques relying on BGS amplitude. Second, radiations modify the Brillouin scattering properties by slightly changing the refractive indices and the acoustic velocities of the silica-based leading to small changes in T and ε dependencies and also to a limited Radiation Induced Brillouin Frequency Shift (RI-BFS) that causes a direct measurement error. Results exhibit an overall decrease of T and ε uncertainties through discrimination process after 1 MGy reaching 0.9°C and 29 με for 0.1 MHz frequency uncertainty for sensors based on the LEAF fiber.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128886247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Tunon de Lara, K. Chah, L. Amez-Droz, P. Lambert, C. Collette, C. Caucheteur
Femtosecond laser pulses are increasingly utilized for the micro/nano-machining of a wide range of materials. They have been effectively employed in the production of fiber Bragg gratings (FBGs) through the implementation of point-by-point, line-by-line, and plane-by-plane processes. This study reports on the use of such lasers for the manufacture of Bragg gratings in pure fused silica planar substrates. In particular, the commercial system known as FEMTOprint was employed. This machine enabled the efficient production of Bragg gratings from bulk silica through several steps. Initially, a waveguide was engraved into the glass substrate through precise control of laser pulses and paths. Subsequently, an access point was created at one edge of the substrate to facilitate the easy connection of a standard optical fiber for light injection and collection. This was accomplished through the use of femtosecond laser pulses, followed by an etching process utilizing KOH to selectively ablate some material and create the necessary open spaces in the substrate. Finally, a third femtosecond laser process was utilized to inscribe a Bragg grating within the waveguide. The reflected amplitude spectrum of the grating was characterized with an FBG interrogator, and the obtained experimental results will be presented in this paper.
{"title":"Femtosecond laser micro/nano-machining of silica glass planar substrates for the production of Bragg gratings","authors":"M. Tunon de Lara, K. Chah, L. Amez-Droz, P. Lambert, C. Collette, C. Caucheteur","doi":"10.1117/12.2678419","DOIUrl":"https://doi.org/10.1117/12.2678419","url":null,"abstract":"Femtosecond laser pulses are increasingly utilized for the micro/nano-machining of a wide range of materials. They have been effectively employed in the production of fiber Bragg gratings (FBGs) through the implementation of point-by-point, line-by-line, and plane-by-plane processes. This study reports on the use of such lasers for the manufacture of Bragg gratings in pure fused silica planar substrates. In particular, the commercial system known as FEMTOprint was employed. This machine enabled the efficient production of Bragg gratings from bulk silica through several steps. Initially, a waveguide was engraved into the glass substrate through precise control of laser pulses and paths. Subsequently, an access point was created at one edge of the substrate to facilitate the easy connection of a standard optical fiber for light injection and collection. This was accomplished through the use of femtosecond laser pulses, followed by an etching process utilizing KOH to selectively ablate some material and create the necessary open spaces in the substrate. Finally, a third femtosecond laser process was utilized to inscribe a Bragg grating within the waveguide. The reflected amplitude spectrum of the grating was characterized with an FBG interrogator, and the obtained experimental results will be presented in this paper.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126707048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vasilios Sarakatsianos, Georgios A. Pappas, E. Pavlopoulou, M. Vamvakaki, S. Pissadakis
A sensing probe is presented for the detection of 2,2,2-trifluoroethanol in the vapor phase, while using poly(vinylidene fluoride (PVDF) thin films, overlaid onto tilted optical fiber Bragg gratings. The 2,2,2-trifluoroethanol sensor operates in the 1.5 μm band, in transmission mode, where the signal of both the core and cladding modes is monitored. Best detectivities obtained are 2 ppm for 2,2,2-trifluoroethanol vapors in ambient atmosphere, for typical response times of 50 min. The sensing probe presented - based on PVDF transductor - shows limited reversibility after being used in the tracing of 2,2,2-trifluoroethanol vapors; its subsequent exposure to nitrogen flow, partly reverses its spectral behavior back to the starting point, denoting the involvement of mechanisms other than physisorption into the underlying transduction. The actual sensing mechanism of 2,2,2-trifluoroethanol vapors while using thin PVDF films is currently under investigation.
{"title":"Optical fiber sensor for the vapor phase detection of Trifluoroethanol","authors":"Vasilios Sarakatsianos, Georgios A. Pappas, E. Pavlopoulou, M. Vamvakaki, S. Pissadakis","doi":"10.1117/12.2678548","DOIUrl":"https://doi.org/10.1117/12.2678548","url":null,"abstract":"A sensing probe is presented for the detection of 2,2,2-trifluoroethanol in the vapor phase, while using poly(vinylidene fluoride (PVDF) thin films, overlaid onto tilted optical fiber Bragg gratings. The 2,2,2-trifluoroethanol sensor operates in the 1.5 μm band, in transmission mode, where the signal of both the core and cladding modes is monitored. Best detectivities obtained are 2 ppm for 2,2,2-trifluoroethanol vapors in ambient atmosphere, for typical response times of 50 min. The sensing probe presented - based on PVDF transductor - shows limited reversibility after being used in the tracing of 2,2,2-trifluoroethanol vapors; its subsequent exposure to nitrogen flow, partly reverses its spectral behavior back to the starting point, denoting the involvement of mechanisms other than physisorption into the underlying transduction. The actual sensing mechanism of 2,2,2-trifluoroethanol vapors while using thin PVDF films is currently under investigation.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"316 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122785586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although ground anchors are widely used in fields of civil engineering, as in soil and rock stabilization or anchoring structures, such as excavation pits, retaining walls or tunnel constructions, the load transfer behaviour has not been entirely investigated yet. Ground anchors are usually monitored by load cells at the anchor head or by strain gauges at selected points along the anchor, which both do not deliver reliable information along the entire anchor. Distributed strain sensing provides an opportunity to get the strain information along the entire length of the anchor, on the tendons as well as in the grout, as we have already shown in a preliminary anchor test. However, there were still lots of issues, which did not allow a general conclusion for all anchor types and ground conditions. Thus we investigated further ground anchors in different soil conditions (clay, rocklike material and gravel), within a research project. This paper gives an overview of the sensor systems used, the obtained results of the anchor pullout tests, gathered experiences and finally gives a brief concept of a monitoring anchor for long term monitoring.
{"title":"Distributed fibre optic sensing during different anchor pullout tests","authors":"H. Woschitz, Madeleine Winkler, V. Račanský","doi":"10.1117/12.2678521","DOIUrl":"https://doi.org/10.1117/12.2678521","url":null,"abstract":"Although ground anchors are widely used in fields of civil engineering, as in soil and rock stabilization or anchoring structures, such as excavation pits, retaining walls or tunnel constructions, the load transfer behaviour has not been entirely investigated yet. Ground anchors are usually monitored by load cells at the anchor head or by strain gauges at selected points along the anchor, which both do not deliver reliable information along the entire anchor. Distributed strain sensing provides an opportunity to get the strain information along the entire length of the anchor, on the tendons as well as in the grout, as we have already shown in a preliminary anchor test. However, there were still lots of issues, which did not allow a general conclusion for all anchor types and ground conditions. Thus we investigated further ground anchors in different soil conditions (clay, rocklike material and gravel), within a research project. This paper gives an overview of the sensor systems used, the obtained results of the anchor pullout tests, gathered experiences and finally gives a brief concept of a monitoring anchor for long term monitoring.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128066077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Armando Rodriguez Rodriguez, J. C. Urroz, Pedro Dieguez Elizondo, M. Bravo Acha, M. López-Amo, Jose Javier Lopez Rodriguez
A water flow and velocity aluminum-coated Fiber Bragg Grating sensor system for open channels was designed, simulated and tested. The sensing head was designed, ruggedized and customized to measure velocities at different depths, in order to calculate the discharge in open channels. This paper shows, for the first time to our knowledge, the simulation of such kind of fiber sensors in open channels.
{"title":"Aluminum coated fiber optic sensor for enhancing flow rate measurement","authors":"Armando Rodriguez Rodriguez, J. C. Urroz, Pedro Dieguez Elizondo, M. Bravo Acha, M. López-Amo, Jose Javier Lopez Rodriguez","doi":"10.1117/12.2678408","DOIUrl":"https://doi.org/10.1117/12.2678408","url":null,"abstract":"A water flow and velocity aluminum-coated Fiber Bragg Grating sensor system for open channels was designed, simulated and tested. The sensing head was designed, ruggedized and customized to measure velocities at different depths, in order to calculate the discharge in open channels. This paper shows, for the first time to our knowledge, the simulation of such kind of fiber sensors in open channels.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133664079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Alonso-Murias, Astrid Saldaña-Sánchez, G. Vázquez, J. Villatoro, D. Monzón-Hernández
An extrinsic fiber Fabry-Perot interferometer (EFFPI) is proposed and implemented for the characterization of waveguides inscribed by the femtosecond-laser direct writing technique. Various waveguides of 7.08 mm in length were inscribed in a soda-lime glass substrate by varying the laser scanning velocity in order to induce different refractive index (RI) changes. The measurement of the RI of the waveguide was carried out by means of an EFFPI formed between the end face of a multicore fiber (MCF) with seven coupled cores and the two polished surfaces of the inscribed waveguide. The end face of the MCF tip provided a broad beam and a wide effective area to ensure a large collection of the reflected light. The optical spectrum obtained by the interference of the multiple reflected beams was transformed to the Fourier domain and visualized in real-time. In the Fourier domain, the waveguides’ optical path length (OPL) was obtained and used to calculate its refractive index since its physical length was fixed and known. To obtain the value of the RI of the medium surrounding the waveguide, the fiber tip was displaced parallel to the polished surface, about 40 μm far from the center of the waveguide. The relative refractive index difference (Δn), which defines the light propagation and the insertion loss in a waveguide, was calculated for each waveguide inscribed at different velocities.
{"title":"Extrinsic fiber Fabry-Perot interferometer for measuring the refractive index of waveguides inscribed in glass","authors":"M. Alonso-Murias, Astrid Saldaña-Sánchez, G. Vázquez, J. Villatoro, D. Monzón-Hernández","doi":"10.1117/12.2678186","DOIUrl":"https://doi.org/10.1117/12.2678186","url":null,"abstract":"An extrinsic fiber Fabry-Perot interferometer (EFFPI) is proposed and implemented for the characterization of waveguides inscribed by the femtosecond-laser direct writing technique. Various waveguides of 7.08 mm in length were inscribed in a soda-lime glass substrate by varying the laser scanning velocity in order to induce different refractive index (RI) changes. The measurement of the RI of the waveguide was carried out by means of an EFFPI formed between the end face of a multicore fiber (MCF) with seven coupled cores and the two polished surfaces of the inscribed waveguide. The end face of the MCF tip provided a broad beam and a wide effective area to ensure a large collection of the reflected light. The optical spectrum obtained by the interference of the multiple reflected beams was transformed to the Fourier domain and visualized in real-time. In the Fourier domain, the waveguides’ optical path length (OPL) was obtained and used to calculate its refractive index since its physical length was fixed and known. To obtain the value of the RI of the medium surrounding the waveguide, the fiber tip was displaced parallel to the polished surface, about 40 μm far from the center of the waveguide. The relative refractive index difference (Δn), which defines the light propagation and the insertion loss in a waveguide, was calculated for each waveguide inscribed at different velocities.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133383185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monika Żuchowska, P. Marć, A. Pakuła, A. Kurzych, G. Stępniewski, R. Buczyński, L. Jaroszewicz
Polymer microtips manufactured at the end face of standard optical fibers have been used for effectively coupling with a selected antiresonant fibers (ARFs). Four tested ARFs had similar geometry, 7 capillaries placed around the central air core. It was shown how such coupling structure modified the ARFs spectral characteristics. Applying polymer microtip successfully excited additional bands. Illumination of the ARF with a microtip that operates as a microlens causes a change in numerical aperture and mode number.
{"title":"Spectral properties of selected antiresonant fibers coupled with standard optical fibers by means of polymer microtips","authors":"Monika Żuchowska, P. Marć, A. Pakuła, A. Kurzych, G. Stępniewski, R. Buczyński, L. Jaroszewicz","doi":"10.1117/12.2678306","DOIUrl":"https://doi.org/10.1117/12.2678306","url":null,"abstract":"Polymer microtips manufactured at the end face of standard optical fibers have been used for effectively coupling with a selected antiresonant fibers (ARFs). Four tested ARFs had similar geometry, 7 capillaries placed around the central air core. It was shown how such coupling structure modified the ARFs spectral characteristics. Applying polymer microtip successfully excited additional bands. Illumination of the ARF with a microtip that operates as a microlens causes a change in numerical aperture and mode number.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124991830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we proposed an in-fiber Mach-Zehnder temperature sensor based on a dual-core fiber (DCF) with one core as the sensing arm suspended in the centre fluidic channel of the DCF and the other core as the reference arm running eccentrically along the fiber. The fluidic channel was infiltrated with silicone oil. Temperature variations would change the refractive index of silicone oil and thus the effective index of the guided mode in the suspended core, thus shifting the interference spectra. The sensitivity of the sensor using a DCF infiltrated with ∼20 cm-long silicone oil was found to be as high as −1.42 nm/°C, comparable to those of the SPR fiber sensors and other interferometric sensors. The measuring range of the sensor was more than 120°C. The proposed sensor could be easily fabricated with good robustness and stability, which makes the sensor suitable for applications such as environment and architecture monitoring.
{"title":"Fiber optic Mach-Zehnder temperature sensor based on dual-core fiber","authors":"Shaoxin Ma, Yufei Zhang, Haiming Qiu, Chunyun Zhao, Xuehao Hu, H. Qu","doi":"10.1117/12.2678433","DOIUrl":"https://doi.org/10.1117/12.2678433","url":null,"abstract":"In this paper, we proposed an in-fiber Mach-Zehnder temperature sensor based on a dual-core fiber (DCF) with one core as the sensing arm suspended in the centre fluidic channel of the DCF and the other core as the reference arm running eccentrically along the fiber. The fluidic channel was infiltrated with silicone oil. Temperature variations would change the refractive index of silicone oil and thus the effective index of the guided mode in the suspended core, thus shifting the interference spectra. The sensitivity of the sensor using a DCF infiltrated with ∼20 cm-long silicone oil was found to be as high as −1.42 nm/°C, comparable to those of the SPR fiber sensors and other interferometric sensors. The measuring range of the sensor was more than 120°C. The proposed sensor could be easily fabricated with good robustness and stability, which makes the sensor suitable for applications such as environment and architecture monitoring.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"2012 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125357157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Faralli, T. Nannipieri, A. Signorini, F. Di Pasquale
We present a novel amplified space-time coding technique which combines cyclic-Simplex and Simplex binary codes to overcome the main limitations of conventional coding for OTDR based ultra-long distance distributed temperature sensing applications. The decoding process is performed in two successive steps, addressing the main issue related to the computational complexity of conventional codes, which increases quadratically with the code lenght, seriously affecting their performance when dealing with extremely long code-words. A link control technique is also proposed to suppress gain transients induced by the EDFA dynamics, avoiding performance degradation due to nonlinear effects and codewords distortion. The proposed scheme provides significant coding gain enhancement and stable operations below the stimulated Raman scattering threshold, pushing the performance of Raman based distributed temperature sensors close to their physical limit using commercial off-the-shelf components.
{"title":"Amplified space-time coding for ultra-long-distance Raman distributed temperature sensing","authors":"S. Faralli, T. Nannipieri, A. Signorini, F. Di Pasquale","doi":"10.1117/12.2678086","DOIUrl":"https://doi.org/10.1117/12.2678086","url":null,"abstract":"We present a novel amplified space-time coding technique which combines cyclic-Simplex and Simplex binary codes to overcome the main limitations of conventional coding for OTDR based ultra-long distance distributed temperature sensing applications. The decoding process is performed in two successive steps, addressing the main issue related to the computational complexity of conventional codes, which increases quadratically with the code lenght, seriously affecting their performance when dealing with extremely long code-words. A link control technique is also proposed to suppress gain transients induced by the EDFA dynamics, avoiding performance degradation due to nonlinear effects and codewords distortion. The proposed scheme provides significant coding gain enhancement and stable operations below the stimulated Raman scattering threshold, pushing the performance of Raman based distributed temperature sensors close to their physical limit using commercial off-the-shelf components.","PeriodicalId":424244,"journal":{"name":"European Workshop on Optical Fibre Sensors","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133898212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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