An optical IM/FSK coding technique for the implementation of a label-controlled arrayed waveguide packet router

• Published in: Journal of lightwave technology Vol. 21; no. 11; pp. 2617 - 2628
• Main Authors: Vlachos, K., Zhang, J., Cheyns, J., Sulur, Chi, N., Van Breusegem, E., Monroy, I.T., Jennen, J.G.L., Holm-Nielsen, P.V., Peucheret, C., O'Dowd, R., Demeester, P., Koonen, A.M.J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2003; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Burst switching; Computer simulation; Differential quadrature phase shift keying; Frequency shift keying; Keying; Labels; Modulation; Multiprotocol label switching; Optical arrays; Optical fiber networks; Optical modulation; Optical packet switching; Optical waveguides; Phase modulation; Routers; Switching; Wavelengths
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2003.819143

In this paper, we present a new concept of optical packet/burst switching suitable for generalized multiprotocol label switched (GMPLS)-based optical networks. In such networks, optical labeled switched paths are being established in a similar way as label-switched paths in MPLS. We use a wavelength label as well as an orthogonally modulated label, with respect to the payload modulation format, and which is encoded using either frequency-shift keying (FSK) or differential phase-shift keying (DPSK). Wavelength is used for switching in the node, whereas the orthogonal label defines the label-switched path. We present both simulation and experimental results to assess transmission performance of the proposed combined modulation scheme. In addition, we propose a suitable optical node architecture that can take advantage of this stacked label concept. Toward this, we use widely tunable wavelength converters to efficiently route IM/FSK (or IM/DPSK) optically labeled packets in an arrayed-waveguide grating (AWG)-based node structure. We present performance simulation results in terms of packet loss ratio and internal block probability. Internal blocking is an inherent problem of AWG optical routers, and a specific wavelength assignment algorithm has been developed to minimize it. Finally, the feasibility of IM/FSK transmission is experimentally demonstrated over an 88-km single-mode fiber span, and novel aspects of FSK generation and detection techniques are presented.