"WDM-DPSK Detection by means of Frequency-Periodic Gaussian Filtering"

A single frequency-periodic narrow filter converts DPSK to intensity modulation in a high number of WDM channels. It also strongly enhances their tolerance to chromatic dispersion and is exploited in a 16x10 Gbit/s transmission over 240 km G.652 fibre with no chromatic dispersion compensation

A novel scheme to detect optical DPSK signals

We propose and demonstrate a novel approach to detect optical differential phase-shift keying signals. The technique is based on differential phase-to-polarization conversion in a polarization-maintaining fiber, so that the polarization-modulated signal can be detected by using a polarizer and a common intensity modulation receiver

High-Speed Bi-directional Optical Wireless System in Non-Directed Line-of-Sight Configuration

We propose and experimentally demonstrate the first bi-directional optical wireless link operating in non-direct line-of-sight (Nd-LOS). The system is based on visible light emitting diode (LED) for downlink and infrared LED for uplink. We achieve around 250 Mbit/s for both downstream and upstream transmission, with the ambient light noise of usual indoor illumination level (500 lx), produced by warm-white LED. 100 Mbit/s are guaranteed inside 12 m$^{2}$ of a common room scenario, without LOS tracking. An optimized discrete multi-tone modulation gives bit-error-ratios always below of the common forward-error-correction threshold of 1.5 ×10$^{-3}$. These results indicate that this scheme has great potential for practical VLC system implementation

PBS-free Polarization-Independent PON Coherent Receiver

We introduce a coherent receiver that, without DSP and/or polarization coding at the transmitter, requires no Polarization Beam Splitter and still is polarization-independent. It is experimentally demonstrated at 10 Gbit/s with a sensitivity of −37.6 dBm at FEC level. It can also be operated at higher bit-rates and finds application in high-speed access and datacenter networks

All-Optical Clock Recovery for NRZ-DPSK Signals

We experimentally demonstrate an optical clock recovery scheme for nonreturn-to-zero differential phase shifting keying (NRZ-DPSK) data. By using an optical circuit made by a proper fiber Bragg filter and a Fabry-Pérot based clock extraction circuit, we obtain a stable and low jitter 10-GHz optical clock signal. This signal shows comparable performance with the original electrical clock in bit-error-rate measurements and oscilloscope triggering operation

Single and Multicast Wavelength Conversion at 40 Gb/s by means of Fast Nonlinear-Polarization-Switching in an SOA

We experimentally demonstrate all-optical wavelength conversion of a 40-Gb/s nonreturn-to-zero signal by means of nonlinear polarization switching in a single semiconductor optical amplifier (SOA). Using a highly nonlinear SOA optimized for very fast gain recovery time, we observe no appreciable penalty for the conventional (single) wavelength conversion. We also obtain, for the first time by using this technique, the simultaneous multiconversion to different wavelengths (four on a 200-GHz frequency grid) of an input signa