135 citations · 203 across the 24 of their papers we have counts for
25 papers
Fully Distributed Fiber-Optic Sensing Enabled by Kalman Filtering
Juan M. Marin, Roman Ermakov, Florian Azendorf +3
Signal fading creates points along the fiber where phase cannot be extracted, so they are conventionally discarded. Instead, we propose a Kalman-based solution for ϕ-OTDR full-fibe…
Fundamentals of Optical Fiber Sensing Schemes Based on Coherent Optical Time Domain Reflectometry: Signal Under Dynamic Temperature Conditions
Roman Ermakov, Huwei Wang, Florian Azendorf +4
We present a theoretical, algorithmic, and experimental study of temperature sensing using -OTDR with coherent detection. A physics-based model is developed to relate the measur…
Multi-Modal Fiber Sensing for OffshoreEnvironmental and Infrastructure Monitoring
Konstantinos Alexoudis, Florian Azendorf, Alvaro Doval +5
Monitoring a 118 km subsea cable using Distributed acoustic, state-of-polarization, and Brillouin sensing captured storm-induced strain up to (dynamic) and $\app…
Precise Localization of High-Voltage Breakdown Events using -Optical Time-Domain Reflectometry on an Optical Ground Wire
Konstantinos Alexoudis, Luke Silvestre, Tom Huiskamp +6
We present -OTDR for detecting and localising full spark-gap breakdowns by analysing backscattered light phase and frequency-domain signatures during high-voltage discharges syn…
Low-Complexity Event Detection and Identification in Coherent Correlation OTDR Measurements
Jasper Müller, Ognjen Jovanovic, Florian Azendorf +7
Pairing coherent correlation OTDR with low-complexity analysis methods, we investigate the detection of fast temperature changes and vibrations in optical fibers. A localization ac…
Remote Sensing with High Spatial Resolution
André Sandmann, Florian Azendorf, Michael Eiselt
Distributed fiber sensing based on correlation-aided phase-sensitive optical time domain reflectometry is presented. The focus is on correlation as an enabler for high spatial reso…
Pressure Wave Detection and Localization in Deployed Underground Fiber using Coherent Correlation OTDR
Florian Azendorf, André Sandmann, Michael Eiselt
A deployed fiber with in-house and underground sections is interrogated with a coherent correlation OTDR. The origin and propagation speed of a hammer-generated pressure wave in th…
Acoustic Sensing after 50 km of Transmission Fibre using Coherent Optical Subassembly
Florian Azendorf, André Sandmann, Wolfgang Reimer +1
A coherent optical subassembly (COSA) is evaluated for coherent-correlation optical time domain reflectometry (CC-OTDR) based fibre sensing. Even though the COSA was originally des…
Acoustic Sensing with Correlation and Coherent Detection using an Integrated Coherent Transceiver
André Sandmann, Florian Azendorf, Saif Alnairat +1
Fiber optic sensing is becoming an important means to physically secure today's network infrastructure. However, a network-wide deployment of the monitors will require cost reducti…
Monitoring of Optical Networks Using Correlation-Aided Time-Domain Reflectometry with Direct and Coherent Detection
Michael H. Eiselt, Florian Azendorf, Andre Sandmann +2
We report on methods to monitor the transmission path in optical networks using a correlation-based OTDR technique with direct and coherent detection. A high probing symbol rate ca…
Simultaneous Temperature and Acoustic Sensing with Coherent Correlation OTDR
André Sandmann, Florian Azendorf, Michael Eiselt
Superimposed temperature variations and dynamic strain applied through a 400 Hz acoustic signal on a 195 m single-mode fiber section are successfully measured using a coherent corr…
Distributed Sensing of Single Mode Fibers with Correlation Techniques
Florian Azendorf, André Sandmann, Michael Eiselt +1
In this paper, we report on the development progress of correlation-based optical time domain reflectometry (OTDR). Substituting the direct detection receiver with a coherent recei…
Optical fiber for remote sensing with high spatial resolution
Michael Eiselt, Florian Azendorf, Andre Sandmann
The use of optical fiber as sensor as well as transmission medium for sensing data is discussed, enabling the use of optically active sensors without power supply at distances of t…
Hollow-core fiber Characterization with Correlation-Optical Time Domain Reflectometry
Florian Azendorf, Bernhard Schmauss, Bo Shi +3
Using a Correlation-OTDR, we characterized the temperature-induced group delay variations of two nested antiresonant nodeless hollow core fibers. The temperature sensitivity of bot…
Temperature dependent latency of jumper cables
Florian Azendorf, Annika Dochhan, Michael Eiselt
The temperature dependence of the latency of an optical signal transmitted over an optical fiber was investigated by means of a correlation OTDR. While the bare fiber showed a line…
Machine Learning-based Anomaly Detection in Optical Fiber Monitoring
Khouloud Abdelli, Joo Yeon Cho, Florian Azendorf +3
Secure and reliable data communication in optical networks is critical for high-speed Internet. However, optical fibers, serving as the data transmission medium providing connectiv…
Gated Recurrent Unit based Autoencoder for Optical Link Fault Diagnosis in Passive Optical Networks
Khouloud Abdelli, Florian Azendorf, Helmut Griesser +2
We propose a deep learning approach based on an autoencoder for identifying and localizing fiber faults in passive optical networks. The experimental results show that the proposed…
Accurate Single-Ended Measurement of Propagation Delay in Fiber Using Correlation Optical Time Domain Reflectometry
Florian Azendorf, Annika Dochhan, Michael H. Eiselt
A correlation optical time-domain reflectometry (COTDR) method is presented, which measures the propagation delay with an accuracy of a few picoseconds. This accuracy is achieved u…
Fiber as a temperature sensor with portable Correlation-OTDR as interrogator
Florian Azendorf, Annika Dochhan, Florian Spinty +3
In this paper, we report on the integration of a Correlation-OTDR into a portable unit (30 cm x 30 cm), based on a multi-processor system on chip (MPSoC) and a small formfactor plu…
Latency Measurement of 100 km Fiber Using Correlation-OTDR
Florian Azendorf, Annika Dochhan, Bernhard Schmauss +1
By means of C-OTDR (Correlation - Optical Time Domain Reflectometry), we measured the latency of100 km fiber with an accuracy of a few picoseconds. Based on iterating 49 measuremen…
Group Delay Measurements of Multicore Fibers with Correlation Optical Time Domain Reflectometry
Florian Azendorf, Annika Dochhan, Florian Spinty +3
Several multi-core fibers (MCF) were characterized using Correlation Optical Time Domain Reflectometry (C-OTDR) in terms of propagation delay and polarization mode dispersion (PMD)…
Characterization of Multi-Core Fiber Group Delay with Correlation OTDR and Modulation Phase Shift Methods
Florian Azendorf, Annika Dochhan, Krzysztof Wilczyński +8
Using a Correlation-OTDR and a modulation phase shift method we characterized four multi-core fibers. The results show that the differential delay depends on the position of the co…
Improvement of accuracy for measurement of 100-km fibre latency with Correlation OTDR
Florian Azendorf, Annika Dochhan, Jim Zou +2
We measured the latency of a 100 km fibre link using a Correlation OTDR. Improvements over previous results were achieved by increasing the probe signal rate to 10 Gbit/s, using di…
Accurate Measurement of Propagation Delay in a Multi-Span Optical Link
Michael H. Eiselt, Florian Azendorf
The principle of Correlation Optical Time Domain Reflectometry (C-OTDR) is proposed to accurately measure the propagation delay over a multi-span optical fiber link. The delay of t…