Transmission capabilities of a coherent real-time UDWDM PON over deployed fibers in two testbeds (Berlin and Darmstadt, Germany) are demonstrated. Extensive coexistence tests including LTE backhauling and GPON, RF-Video, 100G and OTDR were performed. A silicon photonics-integrated CMOS laser was used for parts of the trial.

Coherent optical communication has been well established as the technology of choice for long haul and high bit rate communication systems since a decade ago. Recent technology advances and ongoing price erosion further open the window of opportunity for the application of coherent optical transmission technology in other domains. This paper describes in detail the capabilities, design and implementation of a coherent ultra dense WDM technology for optical metro and access networks. Its capabilities enable a number of attractive options, such as variable downstream bit rates from 150 Mbit/s up to 10 Gbit/s per user, embedded OTDR and the coexistence with legacy systems such as GPON, EPON, XGPON or RF-Video in optical distribution networks. Due to its flexibility and capacity, it is also suitable for deployments in metropolitan networks, as well as for mobile front-haul and back-haul applications.

A filterless coherent PON with channel spacing down to 2.8 GHz and real-time processing in an FPGA is demonstrated. 64-channel operation is verified experimentally using SSB generation at the OLT and fully integrated ONU transceivers.

Coherent technology is the only viable solution to fulfill requirements regarding data rate, reach and splitting factor for optical access. Cost of optics is compensated by savings in system design to achieve an economic solution.

A new architecture for the delivery of 1 Gbit/s sustained to about thousand customers over a shared fibre infrastructure is presented. The architecture is compatible to installed fiber infrastructures and a seamless upgrade is possible.

Coherent UDWDM PONs establish virtual point to point links seperated by the wavelength and without need for TDM. Because of the high receiver sensitivity they clearly outclass TDM or TDM/WDM based PONs in view of flexibility, reach, splitting factor and management complexity. The talk deals with some physical problems and their mitigation in single fiber PONs e. g. backscattering and backreflections into the receiver, channel selectivity and properties of the network.

A PON based on coherent heterodyne receivers is presented. The wavelength selectivity and sensitivity of heterodyne receivers enables a filterless ultra-dense WDM system with long reach and simplified logistics, offering 1Gbit/s sustained datarate per user.

Selon l'invention, des signaux de donnees bidirectionnels sont echanges entre une unite centrale et une pluralite de terminaux de reseau. Une unite de modulation (MOD_OLT) de l'unite centrale module des signaux de donnees (DS1-DS10) sur des sous-porteuses (ω 1 -ω 10 ), genere deux signaux a bande laterale unique optiques (LSB) et (USB) et combine les deux signaux a bande laterale avec des signaux porteurs dephases de 180° (CW, CWI). Les unites de reseau optique selectionnent leur signal de liaison descendante associe et generent un signal de liaison montante associe. Les frequences des signaux de liaison descendante et de liaison montante sont choisies de telle maniere que des reflexions ne perturbent pas le signal selectionne au niveau de l'unite de reseau optique ni les signaux de liaison montante recus au niveau de l'unite centrale.