Author
Mourad Zghal
Other affiliations: King Abdullah University of Science and Technology, Institut Mines-Télécom, École Normale Supérieure
Bio: Mourad Zghal is an academic researcher from Carthage University. The author has contributed to research in topics: Photonic-crystal fiber & Supercontinuum. The author has an hindex of 18, co-authored 101 publications receiving 1145 citations. Previous affiliations of Mourad Zghal include King Abdullah University of Science and Technology & Institut Mines-Télécom.
Papers published on a yearly basis
Papers
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TL;DR: This work demonstrates multiplexing and demultiplexing using both the radial and azimuthal degrees of freedom using a holographic approach that allows over 100 modes to be encoded on a single hologram, across a wide wavelength range, in a wavelength independent manner.
Abstract: Mode division multiplexing (MDM) is mooted as a technology to address future bandwidth issues, and has been successfully demonstrated in free space using spatial modes with orbital angular momentum (OAM). To further increase the data transmission rate, more degrees of freedom are required to form a densely packed mode space. Here we move beyond OAM and demonstrate multiplexing and demultiplexing using both the radial and azimuthal degrees of freedom. We achieve this with a holographic approach that allows over 100 modes to be encoded on a single hologram, across a wide wavelength range, in a wavelength independent manner. Our results offer a new tool that will prove useful in realizing higher bit rates for next generation optical networks.
182 citations
TL;DR: In this paper, the potentials of harnessing the space as an additional degree of freedom for communication applications including free space optics, optical fiber installation, underwater wireless optical links, on-chip interconnects, data center indoor connections, radio frequency, and acoustic communications are reviewed.
Abstract: Time, polarization, and wavelength multiplexing schemes have been used to satisfy the growing need of transmission capacity. Using space as a new dimension for communication systems has been recently suggested as a versatile technique to address future bandwidth issues. We review the potentials of harnessing the space as an additional degree of freedom for communication applications including free space optics, optical fiber installation, underwater wireless optical links, on-chip interconnects, data center indoor connections, radio frequency, and acoustic communications. We focus on the orbital angular momentum (OAM) modes and equally identify the challenges related to each of the applications of spatial modes and the particular OAM modes in communication. We further discuss the perspectives of this emerging technology. Finally, we provide the open research directions and discuss the practical deployment of OAM communication links for different applications.
134 citations
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TL;DR: In this paper, the dispersive Fourier transformation was used to measure shot-to-shot spectral instabilities in femtosecond supercontinuum generation, and the results showed the clear advantages of dispersive wave generation for studying spectral noise during supercontinuity generation.
Abstract: We use dispersive Fourier transformation to measure shot-to-shot spectral instabilities in femtosecond supercontinuum generation. We study both the onset phase of supercontinuum generation with distinct dispersive wave generation, as well as a highly-unstable supercontinuum regime spanning an octave in bandwidth. Wavelength correlation maps allow interactions between separated spectral components to be identified, even when such interactions are not apparent in shot-to-shot or average measurements. Experimental results are interpreted using numerical simulations. Our results show the clear advantages of dispersive Fourier transformation for studying spectral noise during supercontinuum generation.
80 citations
TL;DR: This work uses dispersive Fourier transformation to measure shot-to-shot spectral instabilities in femtosecond supercontinuum generation and studies both the onset phase of supercontinuity generation with distinct dispersive wave generation, as well as a highly-unstablesupercontinuum regime spanning an octave in bandwidth.
Abstract: We use dispersive Fourier transformation to measure shot-to-shot spectral instabilities in femtosecond supercontinuum generation. We study both the onset phase of supercontinuum generation with distinct dispersive wave generation, as well as a highly-unstable supercontinuum regime spanning an octave in bandwidth. Wavelength correlation maps allow interactions between separated spectral components to be identified, even when such interactions are not apparent in shot-to-shot or average measurements. Experimental results are interpreted using numerical simulations. Our results show the clear advantages of dispersive Fourier transformation for studying spectral noise during supercontinuum generation.
80 citations
TL;DR: The proposed technique is promising for high-bit-rate spatial division multiplexing in optical fiber and free space communication systems and investigates the effects of the atmospheric turbulence on the proposed communication system.
Abstract: We experimentally demonstrate an efficient information transmission technique using Laguerre Gaussian (LG) modes. This technique is based on multiplexing and demultiplexing multiple LG modes with different azimuthal and radial components. At the reception, the initially sent modes encoding the information are extracted with high fidelity using a complete decomposition allowing to identify a particular mode from a set of modes within a unique iteration. Importantly, we investigate the effects of the atmospheric turbulence on the proposed communication system. We believe that the proposed technique is promising for high-bit-rate spatial division multiplexing in optical fiber and free space communication systems.
76 citations
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01 Jan 2016
TL;DR: In this paper, the authors present the principles of optics electromagnetic theory of propagation interference and diffraction of light, which can be used to find a good book with a cup of coffee in the afternoon, instead of facing with some infectious bugs inside their computer.
Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.
2,213 citations
TL;DR: Curious wave phenomena that occur in optical fibres due to the interplay of instability and nonlinear effects are reviewed in this article, where the authors propose a method to detect such phenomena.
Abstract: Curious wave phenomena that occur in optical fibres due to the interplay of instability and nonlinear effects are reviewed.
735 citations
TL;DR: In this paper, a detailed overview of stimulated Brillouin scattering (SBS) in single-mode optical fibers is presented, with a particular emphasis on analytical analysis of the backreflected power and SBS threshold in optical fibers with various index profiles.
Abstract: We present a detailed overview of stimulated Brillouin scattering (SBS) in
single-mode optical fibers. The review is divided into two parts. In the first part,
we discuss the fundamentals of SBS. A particular emphasis is given to analytical
calculation of the backreflected power and SBS threshold (SBST) in optical fibers
with various index profiles. For this, we consider acousto-optic interaction in the
guiding geometry and derive the modal overlap integral, which describes the
dependence of the Brillouin gain on the refractive index profile of the optical
fiber. We analyze Stokes backreflected power initiated by thermal phonons, compare
values of the SBST calculated from different approximations, and discuss the SBST
dependence on the fiber length. We also review an analytical approach to calculate
the gain of Brillouin fiber amplifiers (BFAs) in the regime of pump depletion. In the
high-gain regime, fiber loss is a nonnegligible effect and needs to be accounted for
along with the pump depletion. We provide an accurate analytic expression for the BFA
gain and show results of experimental validation. Finally, we review methods to
suppress SBS including index-controlled acoustic guiding or segmented fiber links.
The second part of the review deals with recent advances in fiber-optic applications
where SBS is a relevant effect. In particular, we discuss the impact of SBS on the
radio-over-fiber technology, enhancement of the SBS efficiency in Raman-pumped
fibers, slow light due to SBS and SBS-based optical delay lines, Brillouin
fiber-optic sensors, and SBS mitigation in high-power fiber lasers, as well as SBS in
multimode and microstructured fibers. A detailed derivation of evolutional equations
in the guided wave geometry as well as key physical relations are given in
appendices.
576 citations
TL;DR: A brief review of the research in the field to date is examined and what future directions might hold is considered.
Abstract: Twenty-five years ago Allen, Beijersbergen, Spreeuw, and Woerdman published their seminal paper establishing that light beams with helical phase-fronts carried an orbital angular momentum. Previously orbital angular momentum had been associated only with high-order atomic/molecular transitions and hence considered to be a rare occurrence. The realization that every photon in a laser beam could carry an orbital angular momentum that was in excess of the angular momentum associated with photon spin has led both to new understandings of optical effects and various applications. These applications range from optical manipulation, imaging and quantum optics, to optical communications. This brief review will examine some of the research in the field to date and consider what future directions might hold.
551 citations
TL;DR: In this article, an extended version of the generalized nonlinear Schrodinger equation is presented and discussed for multimode optical fibers and waveguides including polarization effects, high-order dispersion, Kerr and Raman nonlinearities, self-steepening effects, as well as wavelength-dependent mode coupling and nonlinear coefficients.
Abstract: The guided, single-mode propagation of ultrashort optical pulses is commonly described by a well studied and understood generalized nonlinear Schrodinger equation. Here we present and discuss an extended version for multimode optical fibers and waveguides including polarization effects, high-order dispersion, Kerr and Raman nonlinearities, self-steepening effects, as well as wavelength-dependent mode coupling and nonlinear coefficients. We then investigate the symmetry properties of the nonlinear coupling coefficients for the cases of step-index and circularly symmetric conventional fibers and for microstructured fibers with hexagonal symmetry. Finally, we study the computational complexity of the proposed algorithm.
374 citations