Bidirectional higher order cascaded Raman amplification benefits for 10-Gb/s WDM unrepeated transmission systems

Faralli, S.; Bolognini, G.; Sacchi, G.; Sugliani, S.; Pasquale, F. Di

doi:10.1109/jlt.2005.850807

Cited by 23 publications

(23 citation statements)

References 10 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bidirectional distributed Raman amplifi cation [ 5 ] has been implemented by coupling two Raman pumps at 1,450 nm (in forward and backward directions) into a ~93 km single-mode fi ber (SMF); we employed a depolarized fi ber Raman laser (FRL) as forward-propagating pump and a low-RIN depolarized pump based on polarization-multiplexed Fabry-Perot (FP) lasers as backward-propagating pump. We designed the optimal input power levels for Raman pumps and signals employing an in-house developed numerical method [ 6 ] based on the solution of a coupled differential equation system.…”

Section: Experimental Setup and Resultsmentioning

confidence: 99%

Differential Pulse-Width Pair Brillouin Optical Time-Domain Analysis Employing Raman Amplification and Optical Pulse Coding

Taki

Soto

Pasquale

et al. 2013

Lecture Notes in Electrical Engineering

Self Cite

View full text Add to dashboard Cite

Section: Experimental Setup and Resultsmentioning

confidence: 99%

Differential Pulse-Width Pair Brillouin Optical Time-Domain Analysis Employing Raman Amplification and Optical Pulse Coding

Taki

Soto

Pasquale

et al. 2013

Lecture Notes in Electrical Engineering

Self Cite

View full text Add to dashboard Cite

“…Evidently, the FoM is quickly increased up to 300000. This result was achieved principally due to an optimized Raman amplification configuration; the probe wave was amplified through a low noise First-order Raman pump so it is able to travel through the 120 km of lead fiber within a measurable power level, and the pump wave is amplified with an improved "seeded" Second-order Raman configuration [48,49].…”

Section: Discussionmentioning

confidence: 99%

Limits of BOTDA Range Extension Techniques

et al. 2016

View full text Add to dashboard Cite

Abstract-Brillouin-based temperature and strain sensors have attracted great attention of both the academic and industrial sectors in the past few decades due to their ability to perform distributed measurements. Particularly, Brillouin Optical Time Domain Analysis (BOTDA) systems have been applied in many different scenarios, proving particularly useful in those requiring especially wide coverage ranging extremely long distances, such as in civil structure monitoring, energy transportation or environmental applications. The extension of the measuring range in these sensors has therefore become one of the main areas of research and development around BOTDA. To do so, it is necessary to increase the Signal to Noise Ratio (SNR) of the retrieved signal. So far, several techniques have been applied in order to achieve this goal, such as pre-amplification before detection, pulse coding or Raman amplification. Here, we analyze these techniques in terms of their performance limits and provide guidelines that can assist in finding out which is the best configuration to break current range limitations. Our analysis is based on physical arguments as well as current literature results.Index Terms-Brillouin scattering, distributed optic fiber sensing, distributed Raman scattering, optical fibers, optical pulse coding. I. INTRODUCTIONMONG the different available techniques to perform distributed measurements of strain and temperature, Brillouin Optical Time-Domain Analysis (BOTDA) [1,2] is presently recognized as one of the most consolidated. This fiber sensing technology is widely used in different application domains (civil engineering, pipelines, fire detection, etc.). BOTDA technology finds its root on the non-linear optical effect occurring in optical fibers and called Stimulated Brillouin Scattering (SBS) [3]. SBS is an acousto-optic process that manifests as a narrowband amplification of a probe beam when an intense coherent pump light beam is introduced through the opposite end of a single-mode fiber. The distributed feature is provided to the BOTDA by pulsing the pump wave and analyzing the retrieved probe wave as function of the time-of-flight of the pump pulse within the fiber, as depicted in Fig.1.Range and resolution are two of the most important features of these systems, which are normally limited to 20-30 km with 1-2 meter resolution in standard systems [4]. Attenuation, an intrinsic fiber feature, is the limiting factor in terms of range as it reduces the intensity of the signals within the fiber, therefore decreasing the Signal to Noise Ratio (SNR) as the monitored distance increases. Resolution, which is set by the spatial length of the employed pump pulses, is restricted by the associated issues when the pulse duration is reduced. First, a spectral broadening will manifest on the retrieved wave (leading to a higher uncertainty) and also a shorter interaction length will be obtained among the pump and probe wave, leading to a corresponding SNR decrease. Both factors lead to a non-proportional increase of ...

show abstract

“…where the subscripts i and j denote the optical signals propagating at wavelengths λ i and λ j , respectively; P i + (z) and P i − (z) are the respective forward and backward propagating powers; α i is the fiber attenuation; γ i is the Rayleigh scattering coefficient; ν i is the optical frequency corresponding to the wavelength λ i ; h is the Planck constant; ν is the resolution bandwidth of the ASE light; and C ij is the Raman gain/depletion term between wavelengths λ i and λ j given by [9,10] …”

Section: Theory and Simulationsmentioning

confidence: 99%

Study of Raman amplification in DPP-BOTDA sensing employing Simplex coding for sub-meter scale spatial resolution over long fiber distances

Taki¹,

Soto²,

Bolognini³

et al. 2013

Meas. Sci. Technol.

View full text Add to dashboard Cite

The impact of Raman amplification and Simplex coding is studied in combination with differential pulse-width pair Brillouin optical time-domain analysis (DPP-BOTDA) to achieve sub-meter spatial resolution over very long sensing distances. An optimization of the power levels for the Raman pumps, Brillouin pump and signal has been carried out through numerical simulations, maximizing the signal levels and avoiding at the same time nonlinear effects and pump depletion. A reduction of acoustic-wave-induced distortions in the Brillouin gain spectrum down to negligible levels has also been achieved by numerical optimization of the pulse width and duty cycle of return-to-zero Simplex coding, providing significant signal-to-noise ratio enhancement. Strain-temperature sensing over 93 km standard SMF is achieved with a strain/temperature accuracy of 34με/1.7 • C, and 50 cm spatial resolution throughout the fiber length.

show abstract

Bidirectional higher order cascaded Raman amplification benefits for 10-Gb/s WDM unrepeated transmission systems

Cited by 23 publications

References 10 publications

Differential Pulse-Width Pair Brillouin Optical Time-Domain Analysis Employing Raman Amplification and Optical Pulse Coding

Differential Pulse-Width Pair Brillouin Optical Time-Domain Analysis Employing Raman Amplification and Optical Pulse Coding

Limits of BOTDA Range Extension Techniques

Study of Raman amplification in DPP-BOTDA sensing employing Simplex coding for sub-meter scale spatial resolution over long fiber distances

Contact Info

Product

Resources

About