We implement a particle swarm optimization (PSO) algorithm to characterize stimulated Brillouin scattering phenomena in optical fibers. The explicit and strong dependence of the threshold exponential gain on the numerical aperture, the pump laser wavelength and the optical loss coefficient are presented. The proposed PSO model is also evaluated with the localized, nonfluctuating source model an...

Distributed fiber sensing based on Brillouin gain scattering (BGS) principle is a useful way to develop devices capable to measure temperature and/or strain in optical fibers. In these distributed sensors, spatial resolution is a topic of special interest in the distributed fiber sensing field. The influence of the probe-pulse shape in the interaction between the pulsed light and the continuous...

A differential pulse-width pair (DPP) Brillouin distributed fiber sensor is implemented to achieve centimetric spatial resolution over distances of several kilometers. The presented scheme uses a scanning method in which the spectral separation between the two probe sidebands is kept constant, while the optical frequency of the pump is swept to scan the Brillouin spectral response. Experimental...

In this paper, we report experimental results on detecting and analyzing the Brillouin precursor through vegetation at frequencies from 500 MHz to 3GHz. An experimental method to collect data is reported. The outcomes in terms of energy and time-spreading are presented using modulated rectangular and Gaussian pulses, as well as a sequence of rectangular pulses. Using field-collected data, this ...

Stimulated Brillouin interaction between sound and light, known to be the strongest optical nonlinearity common to all amorphous and crystalline dielectrics, has been widely studied in fibres and bulk materials but rarely in optical microresonators. The possibility of experimentally extending this principle to excite mechanical resonances in photonic microsystems, for sensing and frequency refe...

We study the surface elastic response of pure Ni, random alloy FeNiCr and an average in terms lattice Green's function. propose a scheme for computing per-site function their variations. The accurately reproduces mean full alloy. Variation around this is largest near edge Brillouin-zone decays as $q^{-2}$ with wavevector $q$ towards $\Gamma$-point. also present expressions continuum anisotropic...

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 l...

A Q-switched multi-wavelength Brillouin erbium fiber laser (MWBEFL) is demonstrated using a single-walled carbon nanotube–polyethylene oxide (SWCNT–PEO) saturable absorber (SA). The SA is fabricated by cutting off a small part of the developed SWCNT–PEO film and sandwiching it in between two FC/PC (fiber connector/physical contact) fiber connectors. Multi-wavelength combs with ten lasing lines ...