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Integrated magneto-optic (MO) modulators are an attractive but not fully explored alternative to electro-optic (EO) modulators. They are current driven, structurally simple, and could potentially achieve high efficiency in cryogenic and room temperature environments where fJ bit−1 optical interfaces are needed. In this paper, the performance and energy efficiency of a novel MO modulator at room temperature are for the first time assessed. First, a model of the micro-ring-based modulator is implemented to investigate the design parameters and their influence on the performance. Then, a fabricated device is experimentally characterized to assess its performance in terms of bit rate and energy efficiency. The model shows efficient operation at 1.2 Gbps using a 16 mA drive current, consuming only 155 fJ bit−1. The experimental results show that the MO effect is suitable for modulation, achieving error-free operation above 16 mA with a power consumption of 258 fJ bit−1 at a transient limited data rate of 1.2 Gbps.

[EN] We investigate partial response signaling (PRS) as a way of increasing the transmission length achievable by direct detection optical systems. The performance of the duobinary and PRS modulations is evaluated against that of conventional on-off-keying (OOK). We prove by simulation and experimentally that duobinary increases the link distance by up to 1.5 times and PRS by up to 3 times, when no signal processing is employed. The gain is preserved even when equalization is used. PRS is employed also with 4-level pulseamplitude modulation (PAM-4) and is shown to improve the transmission distance by almost 3 times.

[EN] We investigate partial response signaling (PRS) as a way of increasing the transmission length achievable by direct detection optical systems. The performance of the duobinary and PRS modulations is evaluated against that of conventional on-off-keying (OOK). We prove by simulation and experimentally that duobinary increases the link distance by up to 1.5 times and PRS by up to 3 times, when no signal processing is employed. The gain is preserved even when equalization is used. PRS is employed also with 4-level pulseamplitude modulation (PAM-4) and is shown to improve the transmission distance by almost 3 times.

[EN] We investigate two trellis-coded modulation (TCM) schemes for use in next-generation low-cost 400G optical networks. Their performance is evaluated against that of four-level pulse amplitude modulation (PAM-4). We experimentally demonstrate that TCM outperforms PAM-4 at bit rates between 56 and 80 Gbps and thus is a valid candidate for 8¿ × 50G implementations of future 400G wave division multiplexing (WDM) networks. Due to the severe bandwidth limitations of the experimental setup, the feed-forward equalizer and the maximum likelihood sequence estimation equalizer are employed in order to achieve bit error rates below the KP4 threshold of 3 × 10¿4 . We also show that, at 56 Gbps and 1300 nm wavelength, TCM enables optical links of up to 40 km, whereas PAM-4 can only provide transmissions of up to 30 km. We observe that TCM performance degrades faster than that of PAM-4 when we increase the bit rate. For rates higher than 80 Gbps, TCM is not able to improve upon PAM-4 anymore. Thus, only PAM-4 is fit for 4¿ × 100G WDM networks, unless higher bandwidth components are used.

[EN] We investigate two trellis-coded modulation (TCM) schemes for use in next-generation low-cost 400G optical networks. Their performance is evaluated against that of four-level pulse amplitude modulation (PAM-4). We experimentally demonstrate that TCM outperforms PAM-4 at bit rates between 56 and 80 Gbps and thus is a valid candidate for 8¿ × 50G implementations of future 400G wave division multiplexing (WDM) networks. Due to the severe bandwidth limitations of the experimental setup, the feed-forward equalizer and the maximum likelihood sequence estimation equalizer are employed in order to achieve bit error rates below the KP4 threshold of 3 × 10¿4 . We also show that, at 56 Gbps and 1300 nm wavelength, TCM enables optical links of up to 40 km, whereas PAM-4 can only provide transmissions of up to 30 km. We observe that TCM performance degrades faster than that of PAM-4 when we increase the bit rate. For rates higher than 80 Gbps, TCM is not able to improve upon PAM-4 anymore. Thus, only PAM-4 is fit for 4¿ × 100G WDM networks, unless higher bandwidth components are used.

[EN] We propose a PAM-4 modulation scheme with unequally spaced levels in order to mitigate chirp effects caused by IQ modulators. Experimental results of 56 Gb/s transmission over 25 km link demonstrate the robustness of this modulation concept.

[EN] We propose a PAM-4 modulation scheme with unequally spaced levels in order to mitigate chirp effects caused by IQ modulators. Experimental results of 56 Gb/s transmission over 25 km link demonstrate the robustness of this modulation concept.

We experimentally study the transmission performance of 10-Gb/s NRZ-DPSK through concatenated AWG MUX/DMUXs and SOAs employed in an optimized 64×64 optical supercomputer interconnect architecture. NRZ-DPSK offers 9-dB higher dynamic range compared to conventional IM/DD.

We report on an extensive experimental study for adaptive allocation of 16-QAM and QPSK signals inside spectrum flexible heterogeneous superchannel. Physical-layer performance parameters are extracted for use in resource allocation mechanisms of future flexible networks.

In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; the rest of the network was designed according to the channel distribution over the optical spectra required by the optical switch. An experimental validation was also conducted. The experiment consists of a four wavelength division multiplexed (WDM) channel system operating on a WiMax frequency band, and employing an orthogonal frequency-division multiplexing (OFDM) modulation at 625 Mbit/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a one-by-sixteen active optical switch. The results show a negligible power penalty on each channel, for both the best and the worst case in terms of inter-channel crosstalk., QC 20171107

We report on an extensive experimental study for adaptive allocation of 16-QAM and QPSK signals inside spectrum flexible heterogeneous superchannel. Physical-layer performance parameters are extracted for use in resource allocation mechanisms of future flexible networks.

We experimentally study the transmission performance of 10-Gb/s NRZ-DPSK through concatenated AWG MUX/DMUXs and SOAs employed in an optimized 64×64 optical supercomputer interconnect architecture. NRZ-DPSK offers 9-dB higher dynamic range compared to conventional IM/DD.

We experimentally study the transmission performance of 10-Gb/s NRZ-DPSK through concatenated AWG MUX/DMUXs and SOAs employed in an optimized 64×64 optical supercomputer interconnect architecture. NRZ-DPSK offers 9-dB higher dynamic range compared to conventional IM/DD.

We report on an extensive experimental study for adaptive allocation of 16-QAM and QPSK signals inside spectrum flexible heterogeneous superchannel. Physical-layer performance parameters are extracted for use in resource allocation mechanisms of future flexible networks.

We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved for air transmission distances up to 120 cm., QC 20171107

We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved for air transmission distances up to 120 cm.

We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved for air transmission distances up to 120 cm.