L. Stampoulidis

IST-LASAGNE: towards all-optical label swapping employing optical logic gates and optical flip-flops

The Information Society Technologies-all-optical LAbel SwApping employing optical logic Gates in NEtwork nodes (IST-LASAGNE) project aims at designing and implementing the first, modular, scalable, and truly all-optical photonic router capable of operating at 40 Gb/s. The results of the first project year are presented in this paper, with emphasis on the implementation of network node functionalities employing optical logic gates and optical flip-flops, as well as the definition of the network architecture and migration scenarios.

40 Gb/s all-optical packet clock recovery with ultrafast lock-in time and low inter-packet guardbands

We demonstrate a 40 Gb/s self-synchronizing, all-optical packet clock recovery circuit designed for efficient packet-mode traffic. The circuit locks instantaneously and enables sub-nanosecond packet spacing due to thelow clock persistence time. A low-Q Fabry-Perot filter is used as a passive resonator tuned to the line-rate that generates a retimed clock-resembling signal. As a reshaping element, an optical power-limiting gate is incorporated to perform bitwise pulse equalization. Using two preamble bits, the clock is captured instantly and persists for the duration of the data packet increased by 16 bits. The performance of the circuit suggests its suitability for future all-optical packet-switched networks with reduced transmission overhead and fine network granularity.

The Design of an Allo-Optical Packet Switching Network

Recent advances in the all-optical signal processing domain report high-speed and nontrivial functionality directly implemented in the optical layer. These developments mean that the all- optical processing of packet headers has a future. In this article we address various important control plane issues that must be resolved when designing networks based on all-optical packet-switched nodes.

Monolithic GaAs Electro-Optic IQ Modulator Demonstrated at 150 Gbit/s With 64QAM

We report on the experimental demonstration of a GaAs IQ modulator. The device consists of two “nested” Mach-Zehnder modulators for the inphase and quadrature component and is operated at a symbol rate of 25 GBd. Using QPSK, 16QAM, 32QAM and 64QAM, data rates of up to 150 Gbit/s were encoded on a single carrier in one polarization. The individual Mach-Zehnder modulators, and hence, the IQ-modulator have an electro-optic 3 dB bandwidth of 27 GHz and a 6 dB bandwidth larger than 35 GHz. The extinction ratio of the Mach-Zehnder exceeds 20 dB. The devices exhibit small footprint of 2 mm × 40 mm and can be integrated on large-area GaAs wafers using high-yield fabrication processes while providing performance similar to established lithium niobate devices.

Ultra-high Speed, all-optical wavelength converters using single SOA and SOI photonic integrated circuits

We report a new family of ultra-fast all-optical wavelength converters. The device architecture employs a single SOA and filtering elements integrated in silicon-on-insulator substrates. These schemes enable high-integration density and low power consumption.

First demonstration of WDM-enabled all-optical wavelength conversion with a SOA and a 2 nd order micro-ring resonator ROADM

We present the RAWC, the first Ring Resonator Assisted Wavelength Converter employing a SOA and a tunable, Si<inf>3</inf>N<inf>4</inf>-SiO<inf>2</inf> micro-ring resonator ROADM. We demonstrate inverted, non-inverted and WDM-enabled wavelength conversion with low power penalties.

Fabrication and experimental demonstration of the first 160 Gb/s hybrid silicon-on-insulator integrated all-optical wavelength converter

We present a hybrid integrated photonic circuit on a silicon-on-insulator substrate that performs ultra high-speed all-optical wavelength conversion. The chip incorporates a 1.25 mm non-linear SOA mounted on the SOI board using gold-tin bumps as small as 14 μm. Τhe device performs chirp filtering and signal polarity inversion with two multi-mode interference (MMI) - based cascaded delay interferometers (DIs) monolithically integrated on the same SOI substrate. Full free spectral range (FSR) tuning of the DIs is accomplished by two independently tuneable on-chip thermal heaters. We demonstrate 160Gb/s all-optical wavelength conversion with power penalties of less than 4.6dB.

All-Optical Contention Resolution in Space and Wavelength Domain with Ultra-Fast Packet Envelope Detection and Integrated Optical Gates

We present a packet-by-packet contention resolution scheme compatible with both NRZ and RZ modulation formats. 10 Gb/s NRZ and 40 Gb/s RZ error-free operation is shown using integrated optical gates.

Efficient burst reservation protocol: a hybrid signaling protocol for efficient burst-level reservations and quality-of-service differentiation in optical burst switching networks

In this paper we present the efficient burst reservation protocol (EBRP) suitable for bufferless optical burst switching (OBS) networks. The EBRP protocol is a two-way reservation scheme that employs timed and in-advance reservation of resources. In the EBRP protocol timed reservations are relaxed, introducing a reservation time duration parameter that is negotiated during call setup phase. This feature allows bursts to reserve resources beyond their actual size to increase their successful forwarding probability and can be used to provide quality-of-service (QoS) differentiation. The EBRP protocol is suitable for OBS networks and can guarantee a low blocking probability for bursts that can tolerate the round-trip delay associated with the two-way reservation. We present the main features of the proposed protocol and describe in detail the timing considerations regarding the call setup phase and the actual reservation process. Furthermore, we show evaluation results and compare the EBRP performance against two other typical reservation schemes, a tell-and-wait and a tell-and-go (just-enough-time) like protocol. EBRP has been developed for the control plane of the IST-LASAGNE project.

Generation of 40-GHz control signals from flag pulses for switching all-optical gates for use with optical packets

We demonstrate an all-optical circuit capable of generating 40-GHz control signals from flag pulses that can be used to define the switching state of all-optical gates for use with optical packets. The circuit comprises a Fabry-Perot filter and a semiconductor optical amplifier, and with a single pulse it can generate 12 control pulses with 0.64-dB amplitude modulation. With two and three flag pulses the number of control pulses becomes 36 and 54, respectively.