Dario Zeolla

Experimental validation of an analytical model for nonlinear propagation in uncompensated optical links.

We present an experimental validation over different fiber types of an analytical model for nonlinear propagation in uncompensated optical transmission links. An ultra-dense WDM scenario was analyzed, transmitting a comb of ten 120-Gb/s PM-QPSK signals.

Comparison of Different Modulation Formats for 1-Gb/s SI-POF Transmission Systems

In the framework of the currently ongoing effort to find the best transmission solution for Gigabit Ethernet over step-index polymer optical fiber (SI-POF), we give a novel contribution through the comparison of three possible modulation formats: pulse amplitude modulation (PAM)-2, PAM-4, and duobinary, all coupled with electronic equalization at the receiver. We show that on a 50-m SI-POF link using resonant cavity light-emitting diode (RC-LED), duobinary gives the best performance, followed by PAM-2 and then by PAM-4. All evaluations were performed by offline processing experiments.

A New Physical Layer Capable of Record Gigabit Transmission Over 1 mm Step Index Polymer Optical Fiber

In this paper we present the latest results from the POF-PLUS EU Project, demonstrating record transmission of a Gigabit Ethernet compliant stream over 75m of 1mm PMMA SI-POF with 2.5 dB system margin, and over 50 m with 7 dB system margin, in both cases using commercial RC-LED. We believe this is an unprecedented results, showing for the first time that the target distance of 50 meters is reachable with a large system margin. The results were made possible by a careful optimization of the physical layer architecture, which is explained in detail in this paper. The system is experimentally demonstrated over realistic digital stream at the transmitter and real time processing at the receiver.

First demonstration of real-time LED-based Gigabit Ethernet transmission on 50m of A4a.2 SI-POF with significant system margin

We present the first experimental demonstration of a Gigabit Ethernet transmission system capable of reaching 50m on A4a.2 POF (standard 1mm PMMA Step-Index Plastic Optical Fiber) with high system margin (6.5 dB) under real Ethernet traffic flowing between two workstations.

DFE Versus MLSE Electronic Equalization for Gigabit/s SI-POF Transmission Systems

In this letter, we compare three different types of electronic equalization techniques to compensate the limited bandwidth of gigabit/s step-index polymer optical fiber (SI-POF) transmission systems. In particular, we experimentally analyze the performance of a feed-forward equalizer (FFE), a feed-forward plus decision feedback equalizer (FFE+DFE), and a maximum likelihood sequence estimator (MLSE) equalizer in an optical link composed of a resonant cavity light-emitting diode (RC-LED), 50 m of SI-POF, and a photodiode. The investigation is carried out on a real hardware experiment based on available POF optoelectronics, while the equalization is implemented in software using an off-line processing approach. We show that the FFE+DFE solution pays only a limited penalty versus the much more complex MLSE algorithm. Our result shows that the FFE+DFE solution is a very good compromise between performance and complexity for a gigabit/s SI-POF system.

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We report on a transmission experiment over high-performance pure silica core fiber (PSCF) of 16 Nyquist wavelength-division-multiplexed (Nyquist-WDM) channels at a symbol rate of 15.625 GBaud, using polarization-multiplexed (PM) 16 symbols quadrature amplitude modulation (16QAM), resulting in a per-channel raw bit rate of 125 Gb/s. The channel spacing is 16 GHz, corresponding to 1.024 times the symbol rate. The interchannel crosstalk penalty is drastically reduced through the confinement of the signal spectrum within a near-Nyquist bandwidth, achieved with digital filtering and digital-to-analog converters (DACs) operating at 1.5 samples/symbol. The optical line is a recirculating loop composed of two spans of high-performance PSCF with erbium-doped fiber amplifiers only. The transmission distance of 3590 km at a target line bit-error rate (BER) of 1.5 10-2 is achieved at a raw spectral efficiency (SE) of 7.81 b/s/Hz. Assuming a commercial hard forward error correction with 20.5% redundancy, capable of handling the target BER, the net SE is 6.48 b/s/Hz, the highest so far reported for multithousand kilometer transmission of PM-16QAM at ≥ 100 Gb/s per channel. These results demonstrate the feasibility of very high SE DAC-enabled ultra-long-haul quasi-Nyquist-WDM transmission using PM-16QAM with current technologies and manageable digital signal processing complexity.

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We introduce an improved Figure of Merit for comparing different uncompensated fiber links for coherent transmission. The role of fiber dispersion in enhancing system performance is shown and verified by simulations and experiments.

125 Gb/s Quasi-Nyquist DAC-Generated PM-16QAM Transmission Over 3590 km of PSCF

In this paper we demonstrate 1Gb/s bidirectional transmission over a single SI-POF, over the record distance of 75m. We successfully tested our system running real time Gigabit Ethernet traffic generated by a router tester.

Novel figure of merit to compare fibers in coherent detection systems with uncompensated links.

This paper presents a proposal for a new PHY to implement Gigabit Ethernet over SI-POF. The block diagram and rationale of the proposed PHY is described, and its excellent performance is demonstrated in laboratory experiments.

Real-time Gigabit Ethernet bidirectional transmission over a single SI-POF up to 75 meters

We demonstrated a Gigabit Ethernet bidirectional transmission over a single POF. The solution is attractive for very low cost consumer electronic short-distance cabling at high data rate requiring extremely simple installation.