Marcelo Alfonso Soto Hernandez

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In 2016, our research team proposed in an issue of Nature Communications1 the use of multidimensional signal processing, especially image denoising techniques, to improve the signal-to-noise ratio (SNR) of distributed optical ﬁbre sensors. The beneﬁts of t ...

Elastic vibrations in subwavelength structures have gained importance recently in fundamental light–matter studies and various optoacoustic applications. Existing techniques have revealed the presence of distinct acoustic resonances inside silica microwire ...

This invention relates to a system and method to determine the distributed birefringence profile along an optical fibre. Birefringence manifests as different refractive indices for two orthogonal states of polarization of the light propagating in the optic ...

In several applications a temperature contrast between the sensing fibre and the environment is required to detect changes in the environmental heat capacity. For this purpose the process of electrical heating in metallic-coated fibres is theoretically ana ...

The signal-to-noise ratio (SNR) of Brillouin optical time-domain analyzers (BOTDA) is modelled and experimentally validated, using direct detection with and without the use of optical pre-amplification. The behavior of SNR as a function of the Brillouin ga ...

A technique based on the use of orthogonally-polarized pulses is proposed to mitigate the detrimental impact of modulation instability on Brillouin distributed fiber sensors. While the theoretical underpinnings of the method are described by introducing a ...

Image processing is proposed and experimentally demonstrated to improve the capabilities of Raman distributed optical fibre sensors. The here reported technique consists in stacking consecutive one-dimensional Raman Stokes and anti-Stokes traces in two-dim ...

Aiming at taking full advantage of bipolar codes, a method using a three-tone probe is proposed to alleviate the probe power limitation imposed by pump depletion in Golay-coded Brillouin distributed fiber sensors. Experimental results validate the techniqu ...

The distributed fibre sensing technology based on backward stimulated Brillouin scattering (BSBS) is experiencing a rapid development. However, all reported implementations of distributed Brillouin fibre sensors until today are restricted to detecting phys ...

This paper presents a thorough study of the different sources of noise affecting Brillouin optical time-domain analyzers (BOTDA), providing a deep insight into the understanding of the fundamental limitations of this kind of sensors. Analytical and experim ...

Non-local effects have been traditionally identified as one of the most limiting factors of the performance of Brillouin optical time-domain analyzers. These phenomena, directly linked with the energy gained/lost by the pump pulse, limit the probe power an ...

This paper reports on a distributed fiber sensing scheme to achieve sub-metric spatial resolution and long sensing ranges based on a differential pulse-width pair (DPP) Brillouin sensor. The scheme uses a scanning method in which the spectral separation be ...

Numerical solution of the involved governing equations confirm that the commonly used two orthogonal sets of gain- and loss-probes in BOTDA, differently affect the evolution of the pump state-of- polarization, thereby potentially compromising the minimizat ...

The spectrum of the temporal traces obtained from a phase-sensitive optical time-domain reflectometer is theoretically and experimentally analysed, demonstrating its dependence on the incident optical pulse shape. Numerical simulations and theoretical resu ...

We evaluate the Brillouin frequency shift (BFS) determination error when using the Brillouin phase spectrum (BPS) instead of the Brillouin gain spectrum (BGS) in BOTDA setups. We compare the error obtained in the BFS determination in both cases, both with ...

Image processing is proposed to enhance the performance of Brillouin distributed fibre sensors. The technique exploits the two-dimensional nature of the measurements, so that each frequency-position pair is assimilated to a pixel of a noisy image. Based on ...

A novel distributed fibre sensing technique is described and experimentally validated, based on birefringence measurements using coherent Rayleigh scattering. It natively provides distributed measurements of temperature and strain with more than an order o ...

System and methods for producing a plurality of Sinc shaped pulses in the time domain include a light source for providing an input light signal having an input frequency, and at least one spectrum shaper for producing the plurality of Sinc shaped pulses f ...

Commonly, the frequency shift of back-reflection spectra is the key parameter to measure quantitatively local temperature or strain changes in frequency-scanned Rayleigh-based distributed fiber sensors. Cross-correlation is the most common method to estima ...

The distributed Brillouin gain profile of an ultrathin optical microwire made of chalcogenide-glass is characterized using a phase-modulated correlation-domain measurement technique. Method resolves variations of uniformity below 5% along a 13 cm-long micr ...

Marcelo Alfonso Soto Hernandez

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Evaluating measurement uncertainty in Brillouin distributed optical fibre sensors using image denoising

Local activation of surface and hybrid acoustic waves in optical microwires

Method and apparatus for measuring the local birefingence along an optical waveguide

Characterisation of an electrical heating method for metallic-coated optical fibres for distributed sensing applications

Study on the signal-to-noise ratio of Brillouin optical-time domain analyzers

Mitigation of modulation instability in Brillouin distributed fiber sensors by using orthogonal polarization pulses

Reaching millikelvin resolution in Raman distributed temperature sensing using image processing

200 km fiber-loop Brillouin distributed fiber sensor using bipolar Golay codes and a three-tone probe

Distributed forward Brillouin sensor based on local light phase recovery

Sources of noise in Brillouin optical time-domain analyzers

Reaching the ultimate performance limit given by non-local effects in BOTDA sensors

Sub-metric spatial resolution over an extended range using differential time-domain Brillouin sensing

Numerical Studies of Brillouin-induced Polarization Pulling of Probe and Pump in Weakly-Birefringent Optical fibers with Applications to BOTDA

Optimal detection bandwidth for phase-sensitive optical time-domain reflectometry

Gain vs phase in BOTDA setups

Intensifying Brillouin distributed fibre sensors using image processing

Novel technique for distributed fibre sensing based on coherent Rayleigh scattering measurements of birefringence

System and method for producing optical sinc-shaped pulses

Analysis and Reduction of Large Errors in Rayleigh-based Distributed Sensor

Mapping the Uniformity of Optical Microwires Using Phase-Correlation Brillouin Distributed Measurements