Nonlinear effects in optical fibers impose different limitations on the communications link, and an understanding of such effects is almost a prerequisite for actual lightwave-system designers. On the other hand, they offer a variety of possibilities for all-optical signal processing, amplification and regeneration. Using conventional optical fibers for these applications, a length of several kilometres is usually required due to their relatively small nonlinear parameter ( ). Such long fibers pose some practical limitations, concerned namely with the size and stability of the system. The required fiber length is reduced to about 1km using highly nonlinear silica fibers with a smaller effective mode area, and hence, a larger nonlinear parameter. A further reduction in fiber length by one order of magnitude has been achieved in recent years using nanowires and microstructured optical fibers with an extremely small effective mode area and significantly enhanced nonlinear characteristics. Another main advance was the production of highly nonlinear fibers using materials with a nonlinear refractive index higher than that of the silica glass, namely lead silicate, tellurite, bismuth glasses and chalcogenide glasses. Using such highly nonlinear optical fibers, the required fiber length for all-optical signal processing can be dramatically reduced to the order of centimetres. This talk provides an overview of such kind of optical fibers, as well as of some novel dispersive and nonlinear effects exhibited by them.
Mario F. S. Ferreira graduated in Physics from the University of Porto, Portugal, and received the Ph.D. degree in Physics in 1992 from the University of Aveiro, Portugal, where he is now a Professor at the Physics Department. Between 1990 and 1991 he was at the University of Essex, UK, performing experimental work on external cavity semiconductor lasers and nonlinear optical fiber amplifiers. His research interests have been concerned with the modelling and characterization of multi-section semiconductor lasers for coherent systems, quantum well lasers, optical fiber amplifiers and lasers, soliton propagation, polarization and nonlinear effects in optical fibers. He has written about 400 scientific journal and conference publications, and several books, namely: “Optics and Photonics” (Lidel, 2003, in Portuguese), “Topics of Mathematical Physics” (Editora Ciência Moderna, 2018, Brazil, in Portuguese), “Optical Fibers: Technology, Communications and recent Advances” (Ed., NOVA Science Publishers, 2017), “Advances in Optoelectronic Technology and Industry Development” (CRC Press, 2019), “Nonlinear Effects in Optical Fibers” (John Wiley & Sons, OSA, 2011), “Optical Signal Processing in Highly Nonlinear Fibers” (CRC Press, 2020), “Optical Fiber Technology and Applications – Recent Advances” (IOP Publishing, 2021), “Solitons in Optical Fiber Systems” (John Wiley & Sons, 2022), and “Dissipative Optical Solitons” (Springer, 2022). He was the Guest Editor of five Special Issues of “Fiber and Integrated Optics” (Taylor & Francis): “Fiber Optics in Portugal” (2005), “Nonlinear Fiber Optics” (2015), “Optical Fiber Sources and Amplifiers” (2020) and “Quantum Communications” (2020), a joint Special Issue of “Optics Express” and “Applied Optics” (OSA) on “Optical Sensors and Sensing 2019”, and two Special Issues of “Fibers” (MDPI) on “Optical Fiber Communications” and “Specialty Optical Fibers – Material, Fabrication and Applications” (2022), and and a Special Issue of “Fibers” (MDPI) on “Optical Fiber Communications” (2020).
He is Member of IEEE, a Senior Member and a Travelling Lecturer of both of the Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering, He served in various committees of OSA and of SPIE, as well as in the organizing and scientific committees of various international conferences. Actually, he serves also as an Associate Editor or as an Advisor Board Member of several international journals in the area of optics and photonics.