Tiago Silveira

Highly Linear Integrated Optical Transmitter for Subcarrier Multiplexed Systems

A highly linear optical transmitter for radio-over-fiber subcarrier-multiplexed systems is presented. An integrated dual Mach-Zehnder modulator (MZM) is utilized to combine an optical carrier suppressed signal with an optical carrier. The proposed transmitter enables more than 10-dB improvement in the carrier-to-interference ratio compared to a quadrature biased MZM, and similar results to low biased MZM considering similar insertion loss. Negligible radio-frequency power dependence with temperature-induced bias drift is reported, while the low biased MZM is penalized by more than 12 dB for a 15% bias drift. The proposed transmitter reduces the minimum error vector magnitude from 4.2% to 3.5%, when compared to quadrature biased MZM, for a 54-Mb/s orthogonal frequency-division-multiplexed signal.

Simulation and Experimental Characterization of SOA-MZI-Based Multiwavelength Conversion

We present, for the first time, extensive simulation and experimental characterizations of single SOA-MZI-based multiwavelength conversion (MWC) of NRZ data at 10 Gb/s and RZ data at 40 Gb/s under various parametric conditions deploying ITU standard 100- and 200-GHz channel spacing. We analyze, in particular, the physical performance impairments caused by high-order four-wave mixing interference. Our simulation results indicate the promising performance of the MWC up to eight channels with 200-GHz channel spacing. We further experimentally demonstrate four-channel 10-Gb/s error-free MWC with signal regeneration possibilities and 40-Gb/s MWC with moderate penalties, based on commercially available integrated SOA-MZIs. We obtained clear, open converted eye diagrams and achieved negligible difference in channel performance among all MWC channels at both bit rates. Our results proved the excellent performance of a simple scheme for various future network and system applications, such as all-optical wavelength multicast and grid networking.

All-Optical Conversion From RZ to NRZ Using Gain-Clamped SOA

An all-optical converter from return-to-zero (RZ) pulses to the nonreturn-to-zero (NRZ) format is presented. The converter operates in two stages: the laser generated in a gain-clamped semiconductor optical amplifier (SOA) is modulated with the data signal; afterwards this signal is wavelength-converted by cross-gain modulation in a common SOA. The setup is noninverting and can feature wavelength conversion. Experimental error-free conversion from 5- and 40-ps RZ pulses to NRZ format is presented at 10 Gb/s using a 211-1 bit sequence

Electrical dispersion compensation at 10 Gb/s optical single sideband transmission systems

We report different strategies for electrical chromatic dispersion compensation of optical single sideband transmission systems. The performance of the different compensation schemes are evaluated and compared.

All-Optical Vestigial Sideband Generation Using a Semiconductor Optical Amplifier

An all-optical setup to generate vestigial sideband signals based on self-phase modulation in a semiconductor optical amplifier is experimentally demonstrated at 10 Gb/s. Sideband suppressions higher than 15 dB are reported with improved eye opening. Wavelength-independent operation over 26 nm is demonstrated. Increased chromatic dispersion tolerance is verified: a receiver sensitivity penalty of 5.3 dB, relative to back-to-back, is obtained after transmission over 2720 ps/nm; whereas conventional double sideband is penalized by 4.0 dB after 1360 ps/nm

Optical Multicast Technologies by Multi-Wavelength Conversion for Optical Routers

Internet Protocol layer multicast by means of electronic processing is going to be the bottleneck of the next generation optical networks. Optical routers with optical layer multicast capability will become the new focus to overcome the speed limit and simplify the logical network stack structure. In this paper, optical multicast technologies by multi-wavelength conversion are reviewed and assessed with regards to their suitability for optical routers. Furthermore, experimental performance validation of four potential multi-wavelength conversion techniques is demonstrated. Finally, promising technologies for optical multicast routers are suggested.

Mitigation of chromatic dispersion effects on optical single sideband signals by Butterworth filtering

We present a study on the application of electrical dispersion compensation on optical single sideband signals using Butterworth filters, which are optimized for this purpose. Three schemes are studied: pre-equalization, post-equalization and dual-equalization.

All-optical switching with SOA based devices

In this paper, we observe all-optical switching capabilities of semiconductor optical amplifiers. Their most common properties and parameters used for all-optical switching are discussed and described. Some of the common implementations are presented and their advantages, drawbacks and enhancement techniques referred and discussed.

Highly Linear Single Sideband Transmitter for Radio-Over-Fiber Systems

A wavelength-independent single sideband (SSB) transmitter for high-performance radio-over-fiber links is proposed. Third order intermodulation distortion improvement of 9 dB is experimentally verified in back-to-back comparing to a conventional SSB transmitter. Simulation results demonstrate dispersion-independent performance of the proposed transmitter, while the conventional transmitter is further penalized by 8 dB.

Optical Multicasting Performance Evaluation using Multi-Wavelength Conversion by Four-Wave Mixing in DSF at 10/20/40 Gb/s

Transparent optical multicast by multi-wavelength conversion has revealed a brand-new way for performing data multicast function directly in the optical domain without bypassing any electronic processing. Wavelength conversion by four-wave-mixing (FWM) is suitable for high-bitrate data transmission and offers strict transparency to any modulation format. In this paper, experimental results of performance evaluation of multi- wavelength conversion at 10/20/40 Gb/s by FWM in dispersion-shifted fiber are presented and discussed.