Cisco Technology, Inc.

Pirelli Cavi E Sistemi S.p.a.

Gianpaolo Barozzi

Stefano Piciaccia

Fausto Meli

Ornan A Gerstel

Valerio Viscardi

Carlo Tosetti

Mauro Macchi

Damiano Rossetti

Silvia Turolla

Stefano Aina

Cinzia Ferrari

Andrea Marchio

Various example embodiments are disclosed. According to an example embodiment, a dual split passive optical network (PON) may be provided that includes an optical splitting device, and a first and second distribution fibers connected to the optical splitting device. A first cyclic AWG may be coupled to the optical splitting device via the first distribution fiber and a second cyclic AWG may be coupled to the optical splitting device via the second distribution fiber. In other example embodiments, an asymmetric power splitting ratio may be used for the splitting device, or optical seeds and/or optical data signals may be allocated to each of the cyclic AWGs based on a performance of the optical data signals and/or power loss/attenuation of the respective distribution fibers.

Split/smart channel allocated WDM-PON architecture

Systems and methods for verifying performance at an intermediate point in an optical link are provided by virtue of one embodiment of the present invention. One application is locating a fault along a long optical link while minimizing the need for trained personnel to inspect and monitor the link at numerous widely separated locations. At an intermediate point in the link, a portion of the optical signal present is tapped off and demodulated. By use of error correction decoding techniques on the demodulated data, the performance of the link up until that intermediate point may be verified.

Optical link performance monitoring

A efficient and inexpensive optical WDM network architecture with add and drop couplers. Add couplers and drop couplers connected to a network optical fiber with wavelength blocker units which filter out optical signals at selected wavelengths on the optical fiber. The wavelength blocker units are distributed among the add and drop couplers so that each segment of the optical fiber between pairs of neighboring wavelength blocker units has at least three add and drop couplers. More specifically, each segment has the following relationship:THRU+ADD+DROP+LOCAL&#x2266;TOTALwhere THRU is the number of channels passing through the segment; ADD is the number of channels added within the segment; DROP the number of channels dropped within the segment; LOCAL the number of channels confined within the segment; and TOTAL is the total capacity of the optical fiber.

Coupler add/drop node WDM network architecture with periodic cleanup

Systems and methods for controlling power of WDM channels in a WDM receiver. A preamplifier is provided prior to a demultiplexer in the WDM receiver chain. The gain of the preamplifier may be controlled based on power measurements made on individual WDM channels. A filter with controllable tilt may be employed to compensate for amplifier gain tilt and assure that all of the WDM channels remain within the dynamic range of the photodetector and receiver electronics. This provides improved bit error rate performance.

Optical demultiplexer with multi-channel power control and tilt compensation

An optical transmission system has been designed to optimize the use of the spectral emission range of rare-earth-doped fiber amplifiers. The system includes a wide band of channels in the spectral emission range of erbium-doped fiber amplifiers, which is split into two sub-bands, a low sub-band corresponding to the low end of the range and a high sub-band corresponding to the high end of the range. The two sub-bands are separately amplified and optimized, and then recombined without significant competition between the two sub-bands. In addition, an equalizing filter, such as a specialized Bragg filter or interferential filter, is applied to the low sub-band instead of the entire band of channels, thus greatly reducing any equalization need or unequalization effects. In an optical line amplifier for the system, the wide band is amplified in a first stage of a fiber amplifier that operates in a linear condition, the wide band is split into the two sub-bands, and one or the two sub-bands is amplified with the second stage of the fiber amplifier that operates in a saturation condition.

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Cinisello Balsamo, Italy

Gianpaolo Barozzi