Rui Meleiro

All-Optical Burst-Mode Power Equalizer Based on Cascaded SOAs for 10-Gb/s EPONs

This letter proposes a new power equalization scheme based on cascaded semiconductor optical amplifiers, for 10-Gb/s ethernet passive optical networks with uneven topology. For networks with a large number of subscribers, the proposed equalization scheme enables a 16-dB reduction of the receiver dynamic range.

OTDM-to-WDM Conversion based on Wavelength Conversion and Time Gating in a Single Optical Gate

OTDM-to-WDM conversion from 128.1Gbit/s to 3x42.7Gbit/s is achieved by wavelength conversion using side filtering of SPM broadened spectrum in HNLF, followed by a single electro-absorption modulator based optical gate. A maximum 2dB penalty was achieved.

Impact of Self-Phase Modulation on In-Band Crosstalk Penalties

We investigate the performance of a signal impaired by in-band crosstalk, when the shape of the crosstalk signal is distorted. The optical signal-to-noise ratio (OSNR) penalty increases up to 0.5 dB comparing cases with and without distortion due to self-phase modulation in the crosstalk signal. Furthermore, the OSNR penalty significantly depends on the accumulated dispersion of the considered dispersion map of the crosstalk signal. If optimum accumulated dispersion is considered for the crosstalk signal, the crosstalk-induced penalties are higher than expected.

Optically-Addressable Packet Timeslot Interchanger Using a Quadruple Switch Array

We propose and demonstrate a wavelength converter-based time-slot-interchanger architecture consisting of cascaded programmable delay stages. It uses an integrated quadruple switch array of HMZI switches and operated error-free with 10 Gb/s NRZ packets.

In-band crosstalk penalties in optical networks with narrow optical and electric filtering.

Optical cross-connects (OXC) introduce crosstalk and intersymbolic interference due to filtering in the optical signal. We show experimentally and by simulation that higher optical signal-to-noise ratio (OSNR) penalties are obtained for the combined effect of both impairments compared to the sum of the penalties taken independently. Furthermore, the Modified Chernoff Bound is applied for performance estimation, with good accuracy and fast computation time. By using the correct OSNR penalty, the maximum number of cascaded OXC is reduced by 17% relatively to when the penalties are considered separately, for a 2 dB maximum penalty.

Challenges and trends in optical networking: A bottom-up approach

Future bandwidth-intensive services, which will have a wide impact on our daily lives, from entertainment, to business and health-care, demand high capacity, flexible, resilient and secure underlying networks. Simultaneously, rising energy costs and climate change concerns are increasing the pressure to adopt power-efficient solutions in communication networks. Most of these requirements are best fulfilled with optical networks, which are expected to provide the targeted high capacities together with an increasing number of functionalities, leaving behind the label of ldquodumb piperdquo associated to them in early deployments. This paper presents an overview of the challenges and some of the trends in optical networking, covering developments in multiple layers of the protocol stack, from the physical up to the application layer, and aimed at different network segments, from the access to the core network.

All-optical RZ-DPSK packet compressor and decompressor based on MZI-quantum-dot-SOA

All-optical circuits for packet compression and decompression are proposed for compressing and decompressing differential phase shift keyed (DPSK) packets, using optical delay lines and quantum-dot semiconductor optical amplifier (QDSOA) devices in Mach-Zehnder interferometer (MZI) structures. Packet compression and decompression are simulated between 40 Gb/s and 160 Gb/s and an eye opening penalty (EOP) below 0.4 dB is obtained for packets of size up to 1024 bits. For 64 bit packets, the same packet can be consecutively compressed and decompressed 4 times and an EOP of less than 1 dB is obtained.

Application of Fabry-Perot Bragg Grating cavities to optical networks

The growth of bandwidth demand due to increasing number of users and available services, led to development of optical networks. In order to reduce its complexity and cost, Fabry-Perot Bragg Grating (FPBG) based devices are strong candidates to be used in these networks. In the presented work, the same device is able to provide functionalities like optical carrier recovery in a wavelength division multiplexing passive optical network (WDM-PON) and all-optical clock recovery in an all-optical long-haul network. This is aligned with the convergence between metro and long-haul equipment provided by systems integrators, which is currently observed. In order to reduce complexity and cost of the wavelength division multiplexing passive optical network (WDM-PON), the reuse of the downstream carrier by the upstream channel has been suggested [1–4]. On the other hand, all-optical signal processing is a step forward in the development of the next generation optical networks and different techniques to perform all-optical clock recovery have been proposed by several authors [5–8].

Performance Study of a Time Slot Interchanger Based on a MZI-SOA in the Switch Configuration

In this paper we assess the performance of a MZI-SOA based time slot interchanger (TSI). The MZI-SOA operates as a switch that selects the amount of delay to be introduced in the signal at each TSI stage. We analytically calculate the power penalty of the time slot interchanger considering the crosstalk and amplified spontaneous emission noise generated at each MZI-SOA switch. We compare two TSI configurations, one that uses less MZI-SOA switches, and a second that uses one extra switch but significantly reduces crosstalk, which is found to be the main impairment. The results show that power penalties lower than 2.8 dB could be obtained for the 3 stages TSI, for the configuration with one extra switch and an alpha-factor of 6.

40 Gb/s CS-RZ to RZ format conversion using a MZI-SOA integrated switch

Error free carrier suppressed return-to-zero (CS-RZ) to return-to-zero (RZ) modulation and wavelength conversion at 40 Gb/s is demonstrated using a SOA based Mach-Zehnder interferometer (MZI-SOA) integrated switch. CS-RZ to RZ conversion penalty is only 0.3 dB larger than that of RZ wavelength conversion, under the same MZI-SOA operating conditions.