On intranode impairments and engineering rules for an optical label switching router supporting an FSK/IM labeling scheme

This paper presents a study on intranode impairments and engineering rules for a label switching router supporting intensity modulated (IM) optical payload data signals labeled by using frequency-shift key (FSK) modulation. Engineering rules and design guidelines are presented regarding the choice of system parameters such as IM extinction ratio, FSK frequency deviation, alignment of optical filtering stages, label swapping, and node cascadability. The presented rules are derived from insights obtained from computer simulations and experimental validation for a 10-Gb/s IM payload signal.     

All-Optical Data Vortex Node Using an MZI-SOA Switch Array

We propose and demonstrate a new structure of a Data Vortex switch node for all-optical routing of wavelength-division-multiplexing (WDM) 10-Gb/s optical packets. The proposed node consists of two Mach-Zehnder interferometers with integrated semiconductor optical amplifier: an optical and gate and a high-speed optical switch. In the experiment, WDM 10-Gb/s data packets are successfully routed with 1-dB power penalty at a bit-error rate of 10^-9.     

Performance Analysis of an Integrated Spectral OCDMA Technique Including Coupler Imbalance

In this letter, we show, for the first time, that an integrated spectral optical code-division multiple-access (OCDMA) technique has a comparable performance with respect to coherent OCDMA techniques based on a crosstalk analysis. The code set is further studied on its resilience against imbalances in the 3-dB couplers of the en/decoders (E/Ds). The orthogonality remains acceptable for imbalance penalties up to 1 dB. The analysis done in the letter considers a cascade and a tree E/D which shows negligible differences in performance.     

47.4 Gb/s Transmission Over 100 m Graded-Index Plastic Optical Fiber Based on Rate-Adaptive Discrete Multitone Modulation

We experimentally demonstrate a bit-rate of 47.4 Gb/s over 100 m of perfluorinated multimode graded-index plastic optical fiber (GI-POF) by exploiting discrete multitone (DMT) modulation with rate-adaptive bit-loading. The maximum achieved aggregate bit rate is 51.8 Gb/s including DMT transmission overhead (cyclic prefix and preambles) and the standard of 7% of forward-error-correction (FEC) overhead. This is achieved over an intensity-modulated direct-detection (IM-DD) link using a directly-modulated DFB laser (1300-nm) and a multimode fiber-coupled photodetector with a large diameter of 25-$mu$m. The bandwidth requirement is only 12 GHz due to the use of spectral-efficient modulation formats of up to 64-QAM.      

2.26 Gbit/s optical transmission system with 5B6B line coding

A 2.26 Gbit/s optical transmission system featuring four inputs at 565 Mbit/s and binary 5B6B line coding has been realised. The technical feasibility has been tested with various laser diodes on both conventional and dispersion flattened single mode fibre.<>     

Theoretical and Experimental Demonstration of OFM Robustness Against Modal Dispersion Impairments in Radio Over Multimode Fiber Links

A theoretical signal analysis is presented to demonstrate the robustness of optical frequency multiplication (OFM) against modal dispersion impairments in radio-over-multimode fiber links. The predicted system robustness is also experimentally demonstrated with the generation and transmission of 60 Mb/s and 120 Mb/s 64-QAM radio-frequency signals at 24 GHz over three different 4.4-km-long multimode fiber links with different modal group delays and frequency response characteristics, yielding error vector magnitude values below 4% and 4.8% (for 60 and 120 Mb/s, respectively).     

STOLAS: switching technologies for optically labeled signals

GMPLS-based labeled optical burst switching (LOBS) networks are being considered as the next-generation optical Internet. GMPLS includes wavelength switching next to label and fiber (space) switching. We present a new concept of optically labeling bursts of packets suitable for LOBS networks supported by GMPLS. It is based on angle modulation, which enables control information to modulate the phase or frequency of the optical carrier, while payload data are transmitted via intensity modulation (IM). In particular, the optical label is orthogonally modulated, with respect to the payload, using either frequency shift keying or differential phase shift keying. We present a performance analysis of the modulation schemes by means of simulations where the influence of the payload IM extinction ratio and laser linewidth are investigated. In addition, the transmission performance of an IM/FSK combined modulated signal is experimentally validated at 10 Gb/s, demonstrating at the same time an FSK label swapping operation. Finally, a suitable optical label-controlled switch design is proposed that takes advantage of these novel labeling techniques, and efficiently combines widely tunable, fast switching lasers and SOA-MZI wavelength converters with an arrayed waveguide grating router.     

All-optical processing of time-serial IM/DPSK encoded label and payload packets

We demonstrate an all-optical label and payload processor based on nonlinear optical signal processing with semiconductor optical amplifiers. The processor separates the label and the payload, and generates a synchronization pulse, used to control the label comparison operation in an all-optical routing node.     

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

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.     

Design Considerations for a Transparent Mode Group Diversity Multiplexing Link

Mode group diversity multiplexing (MGDM) is an optical multiple-input-multiple-output technique that aims at creating independent communication channels over a multimode fiber, using subsets of propagating modes. This letter deals with the analysis of an MGDM point-to-point link, transparent to the transmission format. The geometry of a mode-group selective multi/demultiplexer is optimized in order to minimize the crosstalk among the channels. The power penalty is calculated when a zero-forcing algorithm is used to mitigate the crosstalk