Simple and Low Cost 10 Gb/s Coherent Transmission for Long Reach PON

131 km transmission (typical LR-PON distance) at 10Gb/s over G.652 fiber is demonstrated exploiting a direct modulated (DM) DFB laser, coherent receiver and electrical filtering obtaining an innovative chirp managed approach. No dispersion compensation (optical or DSP) is exploited

Ultra-Dense WDM-PON 6.25 GHz spaced 8x1 Gb/s based on a simplified coherent-detection scheme

We demonstrate experimentally a novel type of coherent low cost Gigabit-to-the-User Ultra-Dense-Wavelength Division Multiplexing (UD-WDM) PON, featuring 6.25 GHz channel spacing and long reach. Polarization-independent coherent detection is achieved by exploiting a novel scheme which requires only a 3×3 coupler, three photodiodes, basic analogue processing and a common DFB as local oscillator (LO). This avoids the conventional polarization diversity approach. The DFB LO is free running, i.e. not locked in frequency, and is tuned to detect any of the eight channels by simply changing its temperature in a range of 2° C. We achieve 70 km long-reach transmission plus 30 dB attenuation, for a total of > 45 dB optical distribution network loss. This indicates that this solution could be effectively exploited to overlay existing PON infrastructures by UD-WDM

System feasibility of using stimulated Brillouin scattering in self coherent detection schemes

We demonstrate the first self-coherent detection of 10 Gbit/s BPSK signals based on narrow-band amplification of the optical carrier by means of Stimulated Brillouin effect in a common fiber. We found that this technique is very effective only if it is combined with proper line coding and high-pass electrical filtering at the receiver. In this case we obtain OSNR-performance close to the ideal coherent receiver. (C) 2010 Optical Society of Americ

Investigation of the Effects of Chirped RZ Signals in Reducing the Transmission Impairments in R-SOA-Based Bidirectional PONs

Distributed and concentrated reflections represent the two main limitations in reflective-semiconductor optical amplifier (R-SOA)-based passive optical networks (PONs). In this paper, we experimentally discuss how the use of chirped signals in centralized light seeding bidirectional PON can increase the resilience of the system against those two types of reflections. An experimental comparison of the performance of a highly chirped return to zero (RZ) modulation format and the nonreturn to zero is given. Error-free operation is achieved down to 10 dB of signal to crosstalk ratio in presence of distributed reflection, when the upstream signal is highly chirped RZ signal. The same chirped modulation leads to a tolerance of more than dB network return loss due to concentrated reflections. Finally, we assess also the system feasibility of a R-SOA-based full-duplex PON where both the upstream and the downstream are modulated signals

A simple and low-power optical limiter for multi-GHz pulse trains

We study the limiting-amplification capability of a saturated Semiconductor Optical Amplifier (SOA) followed by an optical band-pass filter. We experimentally demonstrate that this simple optical circuit can be effectively exploited to realize a low-power optical limiter for amplitude-modulated pulse trains at multi-GHz repetition rate. We report very large amplitude-modulation-reduction factors for the case of 20 and 40 GHz pulse trains that are super-imposed with modulating frequencies ranging from 100kHz to several GHz. (C) 2007 Optical Society of America

Hybrid Radio over Fiber and Visible Light (RoF-VLC)Communication System

We experimentally demonstrate the integration of Radio-over-Fiber and Visible Light Communication technologies, into a hybrid system for indoor communication. The system, realized according to IEEE 802.11g standard, works effectively at typical office luminance level

A simple and low-power optical limiter for multi-GHz pulse trains

We study the limiting-amplification capability of a saturated Semiconductor Optical Amplifier (SOA) followed by an optical band-pass filter. We experimentally demonstrate that this simple optical circuit can be effectively exploited to realize a low-power optical limiter for amplitudemodulated pulse trains at multi-GHz repetition rate. We report very large amplitude-modulation-reduction factors for the case of 20 and 40 GHz pulse trains that are super-imposed with modulating frequencies ranging from 100 kHz to several GHz

All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency

All-optical self-routing of 40 Gb/s DPSK packets

We demonstrate a self-routing all-optical circuit for switching 40 Gb/s DPSK packets. In our scheme, an all-optical header processor feeds a set-reset flip-flop that drives a coherent wavelength converter. We report an overall limited power penalty