Enhanced 10 Gb/s operations of directly modulated reflective semiconductor optical amplifiers without electronic equalization

We report enhanced 10 Gb/s operation of directly modulated bandwidth-limited reflective semiconductor optical amplifiers. By using a single suitable arrayed waveguide grating we achieve simultaneously WDM demultiplexing and optical equalization. Compared to previous approaches, the proposed system results significantly more tolerant to seeding wavelength drifts. This removes the need for wavelength lockers, additional electronic equalization or complex digital signal processing. Uniform C-band operations are obtained experimentally with < 2 dB power penalty within a wavelength drift of 10 GHz (which doubles the ITU-T standard recommendations)

Polarization Independent self-seeding of Fabry-Peròt laser diodes for WDM-PONs

We obtain stable 1.25 Gb/s self-seeded operation of directly-modulated Fabry-Peròt laser diodes without polarization control, at several wavelengths. Benefits against self-seeded Reflective-SOAs are also discussed

Effective homodyne optical phase locking to PSK signal by means of 8b10b line coding

We demonstrate a novel technique that allows effective homodyne optical phase locking to a phase shift keying (PSK) signal with a residual carrier. We exploit 8b10b coding of the signal in order to reduce its low frequency spectral content, suppressing the data-to-phase crosstalk effect. In a transmission experiment on a 10 Gb/s binary PSK signal (8 Gb/s before coding), we achieved transmission over 215 km of dispersion-compensated, installed single-mode fibre, with no penalty compared to back-to-back at a bit error ratio of 10(-3). The proposed solution is applicable to other modulation formats, including multi-level amplitude and/or phase modulation formats

Uncooled and Polarization IndependentOperation of Self-Seeded Fabry–PérotLasers for WDM-PONs

— We present for the first time an experimental characterization of uncooled and polarization-insensitive operations of directly modulated self-seeded Fabry–Pérot laser diodes (FP-LDs) for wavelength division multiplexed passive optical networks (WDM-PONs). Polarization-insensitive operations are achieved through the combination of nonreciprocal optical elements placed both at the FP-LD and the WDM distribution node, which is placed within the PON. Compared to self-seeded reflective semiconductor optical amplifiers, the FP-LDs show narrower emission linewidth, resulting in improved resilience to chromatic dispersion. The 1.25-Gb/s WDM system operation is assessed on 32 channels in the C-band over a 100-GHz grid and in a wide range of ambient temperature (0 °C–60 °C). The results shown in this letter promote the self-seeded uncooled FP-LDs to a potential candidate for WDM-PON deployments

Modulation Format Transparent Subcarrier Reuse by Feed Forward Current Injection in a Reflective SOA

We experimentally demonstrate remodulation of a 2.4GHz microwave channel by using feed-forward current injection in a reflective-SOA. We tested the scheme with different modulation formats (BPSK, 16-QAM, 64-QAM) at 155Mbaud

Symmetric 10 Gb/s WDM-PON based on a cross wavelength-reusing scheme to avoid rayleigh backscattering and maximize band usage

We demonstrate a 10 Gb/s symmetrical WDM-PON exploiting a cross seeding scheme to enable wavelength reusing. It avoids reflection-induced penalties, and effectively removes any extinction-ratio constraint by means of DPSK modulation format in the downlink

Enhancing Resilience to Rayleigh Crosstalk by means of Line Coding and Electrical Filtering

We demonstrate a technique that ameliorates the performance of bidirectional systems impaired by in-band Rayleigh crosstalk, which is common in passive optical access networks based on centralized remote wavelength feeding. The technique is based on the combined use of a suitable line coding and ad hoc postdetection electrical filtering. Therefore, it can be seamless implemented in optical access systems and it is easily scalable with the data rate. We experimentally assess the technique by using a 8B10B coded 1.25-Gb/s signal. We report an increased tolerance to the signal-to-crosstalk ratio by about 5 dB

Single feeder bidirectional WDM-PON with enhanced resilience to Rayleigh-backscattering

We report a system demonstration of 6dB-enhanced tolerance to distributed reflections for WDM-PONs using commercial 1.25Gb/s SFP reflective transceivers. The scheme, based on 8B10Bcoding and high-pass electrical filtering, works with CW or 10Gb/s downstream seeding