Computational intelligence in photonics technology and optical networks: A survey and future perspectives Christos Riziotis a, * , Athanasios V. Vasilakos b a Department of Telecommunications Science and Technology, University of Peloponnese, Karaiskaki Street, 22 100 Tripoli, Greece b Department of Computer and Telecommunications Engineering, University of Western Macedonia, Agios Dimitrios Park, 50 100 Kozani, Greece Received 19 June 2006; received in revised form 8 June 2007; accepted 12 June 2007 Abstract The continuous growth of broadband communications, multimedia services and Internet is absolutely related to the deployment and operation of optical networks. Despite optical fibers’ enormous physical bandwidth the development of optical networks for today’s advanced, reliable and guaranteed-type services, require an efficient management of the bandwidth together with an orthological and careful use of optical components given their high manufacturing cost. These requirements have lead to the need for sophisticated photonic devices and to optical networks’ implementations of increased functionality and associated thus complexity. For the efficient consideration of those problems different design and optimization techniques have been applied to date. However, as the complexity increases, the use of computational intelligence (CI) in those problems is becoming a unique tool of imperative value. In this paper we review in a unified approach the applications of CI starting from the physical layer and ending to services layer, given that here there is a strong relation and unique interplay between components’ technology and network issues, being sharing the common tar- get of physical bandwidth’s efficient utilization. The applicability of different CI classes (genetic algorithms and evolution strategies, fuzzy systems, and artificial neural networks) in optical wavelength division multiplexing (WDM) networks is identified and evaluated. Furthermore specific optical networks’ optimization problems are categorized. Being a rapidly growing area, new trends, such as evolutionary game theory, in understanding and design of large scale Optical Network are also identified and discussed. The paper seeks to review the aforementioned areas, identify new problems and trends, triggering this way new research efforts for interdisciplinary cooperation between researchers. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Computational intelligence; Evolution strategies; Genetic algorithms; Neural networks; Fuzzy systems; Optimization; Optical networks; WDM; Photonic components 1. Introduction Optical networks form undoubtedly the core technology for the construction and operation of today’s and next generation’s broadband communications and multimedia services, such as video on demand, videoconferencing, 0020-0255/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ins.2007.06.012 * Corresponding author. Tel.: +30 6977078736. E-mail addresses: Christos.Riziotis@ieee.org (C. Riziotis), vasilako@ath.forthnet.gr (A.V. Vasilakos). Information Sciences 177 (2007) 5292–5315 www.elsevier.com/locate/ins