227 research outputs found
"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 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. 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
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