Open Access
WDM bi-directional transmission over 35 km amplified fiber-optic bus network using Raman amplification for optical sensors
(Optical Society of America, 2005) Díaz Lucas, Silvia; Lasheras, Gorka; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We demonstrate a novel distributed fiber Raman amplified bus topology used for WDM transmission over 35 km of single-mode fiber by use of a multiwavelength Raman pump laser and eight Fiber Bragg gratings (FBGs). This topology reduces the number of addressing wavelengths needed at the head of the bus. Furthermore, by relocating the FBGs’ wavelengths of a first section, it is obtained power transparency at the end of the overall bus, without requiring any additional pump source. We show how the topology allows the received powers from the first section sensors to be equalized and partially amplify the overall network. We investigate how the performance depends on the launched pump power. Results obtained with this new configuration are compared with those achieved in a previously reported optically amplified bus topology.
Open Access
46-km-long Raman amplified hybrid double-bus network with point and distributed Brillouin sensors
(IEEE, 2012) Fernández Vallejo, Montserrat; Olier Aguado, David; Zornoza Indart, Ander; Pérez Herrera, Rosa Ana; Díaz Lucas, Silvia; Elosúa Aguado, César; Bariáin Aisa, Cándido; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We experimentally demonstrate a 46-km hybrid network that combine point and distributed Brillouin sensors. The proposed sensor network multiplexes low-cost intensity point sensors based on fiber-optic tapers, which are able to measure vibrations in the 0.01 to 50 Hz frequency range. The sensor network with a double-bus is a low noise configuration, which offers a higher optical signal to noise ratio and dynamic range than a single-bus. Thus, the number of sensors to be multiplexed could increase or we could reach further distances. The system also deploys remote distributed Raman amplification to extend the sensing range.
Open Access
Stable multi-wavelength erbium fiber ring laser with optical feedback for remote sensing
(IEEE / OSA, 2015) Díaz Lucas, Silvia; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we demonstrate a stable fiber sensing system for remote temperature measurements, where the sensing element is an array of four fiber Bragg gratings (FBGs) and sensor interrogation is achieved with a multi-wavelength erbium fiber ring laser. By introducing a feedback fiber loop in a fiber ring cavity, four laser emission lines were obtained simultaneously in single-longitudinal mode operation (SLM). The power instability obtained was lower than 0.5 dB with an optical signal-to-noise ratio (OSNR) higher than 50 dB for all the emitted wavelengths. The application of this system for remote temperature measurements has been demonstrated even though the SLM regime cannot be preserved.
Open Access
Comparison of wavelength-division-multiplexed distributed fiber Raman amplifier networks for sensors
(Optical Society of America, 2006) Díaz Lucas, Silvia; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A novel distributed fiber Raman amplified star topology used for optical sensor wavelength-division multiplexing is proposed. The performance of this star configuration is compared to an optically amplified bus topology. The two different network topologies are compared and demonstrated experimentally and theoretically as means of gathering information from four wavelength-division-multiplexed photonic sensors. We report how the star configuration yields better signal-to-noise ratios than the bus topology. Furthermore, this improvement is made without increasing the complexity of the regular star topologies.
Open Access
Resilient amplified double ring optical networks to multiplex optical fibre sensors
(IEEE / OSA, 2009) Fernández Vallejo, Montserrat; Pérez Herrera, Rosa Ana; Elosúa Aguado, César; Díaz Lucas, Silvia; Urquhart, Paul; Bariáin Aisa, Cándido; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We report the experimental demonstration of two configurations of an amplified optical fibre double ring network for the multiplexing of sensors. The networks are designed to be inherently resilient to fibre failures because they enable simultaneous interrogation of all the optical fibre sensors using both rings. The first design demonstrates the feasibility of the so called 'dedicated protection' and the second one 'shared protection' for fibre optic intensity sensors. Raman amplification is used to overcome the losses of the couplers used in the rings, providing power transparency. The first network uses Raman amplification in both constituent rings but in the second one Raman pumping is activated only when a fibre failure occurs. We demonstrate how the topology allows the received powers from the sensors to be equalized.
Open Access
Long-range hybrid network with point and distributed Brillouin sensors using Raman amplification
(Optical Society of America, 2010) Zornoza Indart, Ander; Pérez Herrera, Rosa Ana; Elosúa Aguado, César; Díaz Lucas, Silvia; Bariáin Aisa, Cándido; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We propose a novel concept for hybrid networks that combine point and distributed Brillouin sensors in a cost-effective architecture that also deploys remote distributed Raman amplification to extend the sensing range. A 46-km proof-of-concept network is experimentally demonstrated integrating point vibration sensors based on fiber Bragg gratings and tapers with distributed temperature sensing along the network bus. In this network the use of Raman amplification to compensate branching and fiber losses provides a temperature resolution of 0.7°C and 13 m. Moreover, it was possible to obtain good optical signal to noise ratio in the measurements from the four point vibration sensors that were remotely multiplexed in the network. These low-cost intensity sensors are able to measure vibrations in the 0.1 to 50 Hz frequency range, which are important in the monitoring of large infrastructures such as pipelines.
Open Access
Dual-wavelength single-longitudinal-mode erbium fiber laser for temperature measurements
(SPIE, 2014) Díaz Lucas, Silvia; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A dual-wavelength erbium fiber laser with single-longitudinal-mode characteristic is proposed and demonstrated. The system uses a 7-m-long highly doped erbium-doped fiber as the primary gain medium while two fiber Bragg gratings (FBGs) act as a wavelength selection mechanism. The sensing capability of the FBGs gives this source the possibility to be also used in a dual-sensor multiplexing scheme. The system is very stable and suitable for sensor multiplexing.
Open Access
Optical fiber bus protection network to multiplex sensors: experimental validation of self-diagnosis
(IEEE, 2012) Pérez Herrera, Rosa Ana; Urquhart, Paul; Schlüter, Marcel; Díaz Lucas, Silvia; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The experimental demonstration of a resilient wavelength division multiplexed (WDM) fiber bus network to interconnect sensors is reported. The network recovers operation after failures and it performs 'self-diagnosis', the identification of the failed constituent(s) from the patterns of surviving end-toend connections at its operating wavelengths. We provide clear evidence for the channel arrivals predicted by theory. In doing so, we explore the potential for spurious signals caused by reflections from broken fiber ends. Appropriate precautionary measures, especially the imposition of electronic thresholds at the receivers, can greatly reduce the scope for false diagnoses. Software to predict the failure site within the network from the arriving channels at the receivers is also reported. We describe how to coordinate self-diagnosis with protection switching so as to reduce the momentary service interruption.