Ultrafast all-optically controlled 2×2 crossbar switch

All-optical packet switching using all-optical routing control, where both ultrafast address recognition and routing of photonic packets were all optically performed on a header with 4 picosecond bit period, was demonstrated. Packets were self-routed through a node with no need for optoelectronic conversion. Terahertz optical asymmetric demultiplexer (TOAD) was used as an optically controlled 2×2 routing switch and as an all optical routing controller. TOAD read the individual address bits in the tightly compressed packet header and set the state of the routing switch. The bit-error rate at the switching element was measured to be less than 10-9

Signal processing in high speed OTDM networks

This paper presents the design and experimental results of an optical packet-switching testbed capable of performing message routing with single wavelength TDM packet bit rates as high as 100 Gb/s

Delay dynamics of neuromorphic optoelectronic nanoscale resonators: Perspectives and applications

With the recent exponential growth of applications using artificial intelligence (AI), the development of efficient and ultrafast brain-like (neuromorphic) systems is crucial for future information and communication technologies. While the implementation of AI systems using computer algorithms of neural networks is emerging rapidly, scientists are just taking the very first steps in the development of the hardware elements of an artificial brain, specifically neuromorphic microchips. In this review article, we present the current state of the art of neuromorphic photonic circuits based on solid-state optoelectronic oscillators formed by nanoscale double barrier quantum well resonant tunneling diodes. We address, both experimentally and theoretically, the key dynamic properties of recently developed artificial solid-state neuron microchips with delayed perturbations and describe their role in the study of neural activity and regenerative memory. This review covers our recent research work on excitable and delay dynamic characteristics of both single and autaptic (delayed) artificial neurons including all-or-none response, spike-based data encoding, storage, signal regeneration and signal healing. Furthermore, the neural responses of these neuromorphic microchips display all the signatures of extended spatio-temporal localized structures (LSs) of light, which are reviewed here in detail. By taking advantage of the dissipative nature of LSs, we demonstrate potential applications in optical data reconfiguration and clock and timing at high-speeds and with short transients. The results reviewed in this article are a key enabler for the development of high-performance optoelectronic devices in future high-speed brain-inspired optical memories and neuromorphic computing. (C) 2017 Author(s).Fundacao para a Ciencia e a Tecnologia (FCT) [UID/Multi/00631/2013]European Structural and Investment Funds (FEEI) through the Competitiveness and Internationalization Operational Program - COMPETE 2020National Funds through FCT [ALG-01-0145-FEDER-016432/POCI-01-0145-FEDER-016432]European Commission under the project iBROW [645369]project COMBINA [TEC2015-65212-C3-3-PAEI/FEDER UE]Ramon y Cajal fellowshipinfo:eu-repo/semantics/publishedVersio

Singly generated quasivarieties and residuated structures

A quasivariety K of algebras has the joint embedding property (JEP) iff it is generated by a single algebra A. It is structurally complete iff the free countably generated algebra in K can serve as A. A consequence of this demand, called "passive structural completeness" (PSC), is that the nontrivial members of K all satisfy the same existential positive sentences. We prove that if K is PSC then it still has the JEP, and if it has the JEP and its nontrivial members lack trivial subalgebras, then its relatively simple members all belong to the universal class generated by one of them. Under these conditions, if K is relatively semisimple then it is generated by one K-simple algebra. It is a minimal quasivariety if, moreover, it is PSC but fails to unify some finite set of equations. We also prove that a quasivariety of finite type, with a finite nontrivial member, is PSC iff its nontrivial members have a common retract. The theory is then applied to the variety of De Morgan monoids, where we isolate the sub(quasi)varieties that are PSC and those that have the JEP, while throwing fresh light on those that are structurally complete. The results illuminate the extension lattices of intuitionistic and relevance logics

Analytical evaluation of improved access techniques in deflection routing networks

This paper presents an extension of a known analytical model for the performance evaluation of nonpriority deflection routing networks in uniform traffic. The extension allows the analysis of improved access techniques. The key features of the analytical technique are described by casting it in a very simple setting: nonpriority hot-potato in a two-connected slotted shufflenet (SN) network. Results are presented for three access techniques: transmit-no-hold (TXNH), transmit-hold (TXH), and bypass queuing (BQ

250-Gb/s self-clocked optical TDM with a polarization-multiplexed clock

In this paper we report the first demonstration of all-optical time demultiplexing at 250 Gb/s with self-clocking using polarization multiplexing of the clock and data. To achieve such high speed, an ultra high-speed device known as the Terahertz Optical Asymmetric Demultiplexer (TOAD) is used. We also demonstrate self-clocked address recognition and routing control of a photonic switch at 250 Gb/s. The bit-error rate at the switch output was measured to be less than 10-9

MINIMUM LOSS NODE STRUCTURES FOR DEFLECTION ROUTING TRANSPARENT OPTICAL NETWORKS

New node structures with a single transmitterheceiver (TW RX) using single-buffer deflection routing' are proposed here for two-connected slotted multihop networks

NEW STRUCTURES OF THE OPTICAL NODE IN TRANSPARENT OPTICAL MULTIHOP NETWORKS USING DEFLECTION ROUTING

New single-receiver/single- transmitter/single- buffer node structures for two-connected multihop transparent optical packet-switching network8 with deflection routing are introduced. A ShuBeNet topology an uniform trafic is adopted to compare various shared optical memory schemes and their control algorithms. These simple structures minimize the number of crossbar switches needed at the node and have moderate control complexity, while still yielding high throughput and low delay. Analytical results are obtained by an estension of the existing theory and verified by simulation