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Semiconductor quantum dots are often proposed as an ideal means to achieve non-linear interactions and photon switching in semiconductor integrated circuits. We examine here the use of the electron spin degree of freedom as a means to achieve a controllable quantum switching of single photons and trains of photons. We examine some types of spin-based quantum switches, and the design principles upon...
Single photon detectors based on superconductor nanowires (SNSPDs) provide high efficiency and good timing performance, as well as broad optical detection bandwidth. To move towards applications in high bandwidth quantum communication and processing, ultrafast detectors with high efficiency are needed. We realize compact SNSPDs with sub-micrometer effective length by aligning the nanowire perpendicular...
Tripartite entangled states, such as Greenberger-Horne-Zeilinger (GHZ) and W states, are appealing for tests of fundamental aspects of quantum mechanics, as well as for implementations of quantum communication protocols. While the information is typically encoded in the polarization or path of the photons, we propose a feasible scheme to generate W states that are entangled in the energy degree of...
We present switching experiments performed on pillar microcavities containing a collection of quantum dots (QDs). Switching events are probed using QD luminescence, after ultrafast optical injection of free carriers. We observe large switching amplitudes (by as much as 20 linewidths), as well as differential switching of the pillar modes under inhomogeneous pumping. Through transient coupling of QDs...
The ever-increasing demand for capacity in optical networks is driving the development of transponders capable of achieving spectral efficiencies of up to 8 bit/s/Hz using advanced modulation formats and coherent-detection. However, operating at the highest spectral efficiency is accomplished at the expense of shorter transparent reach, potentially requiring the deployment of additional expensive...
We demonstrate real-time CD equalization (CDE) for coherent optical transmission systems using a low complexity time-domain (TD) multiplierless finite-impulse response (FIR)-based equalizer, based on a field-programmable gate array (FPGA) implementation. The real-time operation is performed for a single-channel 2.5 Gb/s QPSK optical signal with a performance penalty of only ∼0.15 dB with respect to...
We report on the design, fabrication and electro-optical characterization at T = 2.9 K of a photon number resolving detector designed to obtain a pulse-position resolution. This pulse-position-resolving detector (PPRD) is based on the spatial multiplexing of four superconducting nanowire avalanche photodiodes (SNAPs) [8, 9] connected in series. We choose to exploit the 2-SNAP configuration (i.e.,...
Other than merely a bandwidth pipe, current and future network applications will have other requirements such as maximum end-to-end latency and the type of recovery from failure. The added complexity will require a central intelligence such as a software-defined networking (SDN) orchestrator to compute and keep track of the resources allocated to such applications. In such an SDN-orchestrated network,...
In this paper, we report on a field trial, demonstrating the seamless wireless extension of a real-world 2.5 Gbit/s Gigabit passive optical network (GPON) using a hybrid fiber wireless (HFW) bridge. Direct optic-to-RF conversion using a novel coherent photonic mixer (CPX) and direct RF-to-optic radio access units (RAU) were developed and employed to extend the reach of the GPON network using a 455...
In this paper, a data-center network (DCN) system that distinguishes Hadoop job types and allocates optical/electrical circuits to data flows depending on the types automatically is proposed. The proposed system calculates the predicted shuffle value (PSV) of the Hadoop job and determines which type of flow is allocated by comparing the PSV and the threshold value. The PSV can be calculated from a...
In the framework of the EU-funded research project “FABULOUS” we experimentally demonstrate an innovative FDMA-PON architecture whose upstream transmission is based on a reflective Mach-Zehnder modulator, reaching an overall upstream capacity of 32 Gbps per wavelength over 31 dB ODN loss in several previously published experiments targeting 1 Gbps per user and using 16-QAM as a modulation format....
This paper describes the concept of sensor over fibres (SoF), consisting of many sensor heads connected by fibre networks. SoF transfer waveforms from the sensor heads and performs joint signal processing to achieve high-resolution and agile imaging, while wireless sensor networks are digital networks to collect measured data at small sensors. SoF can compile information from sensor heads coherently...
We describe low end-to-end latencies of 6.69 ms in the 5G CHARISMA network, that has been optimised for both device and system technologies speed, as well as with its virtualised, hierarchical and distributed, edge-centric architecture, that processes data as near as possible to their source and destination. Such an ultra-high speed 5G network can be utilised in intelligent transport system (ITS)...
Coherent optical systems offer enhanced possibilities to increase data transmission capacity. To implement these systems, optical demodulators are required to decode the data. In this context, optical demodulators for a Quadrature Phase Shift Keying (QPSK) modulation based on 90° hybrid couplers are presented. The devices were produced by direct UV-laser patterning on sol-gel derived organic-inorganic...
The report observes the results of radar signatures investigating and the road objects radar images (RI) statistical characteristics analysis in relation to automobile radar system (ARS) of collisions preventing. The results of applying the method for investigating in the processing of the RI of the road situation, obtained as a result of full-scale tests of the ARS model, are presented. Road objects...
The unified program architecture of real time vision system (VS) with several fields of view construction is described. The offered architecture provides both onboard and stationary usage. In case of stationary usage, it provides determination of location and trajectory of objects movement in the ordered system of co-ordinates. Principles of open architecture, componential technology and use of standard...
VANETs are playing an increasing role in the development of communication and traffic assistance in transportation. Therefore mobility simulations are needed to predict the impact of new ideas on the VANET. But the interest in adding new applications to vehicles may differ largely according to the traffic scenarios. It seems too complicated to have one integrated mobility simulator that deals with...
The development of advanced InP-based transmitter PICs of increasing complexity and integrating periodically capacitive-loaded (CL) Travelling Wave Electrode (TWE) Mach-Zehnder modulators is reported and discussed in examples.
We propose and demonstrate signal encryption schemes using digital chaos for orthogonal frequency division multiplexing (OFDM) signals, where discrete Fourier transform (DFT) and Walsh-Hadamard transform (WHT) are applied as chaotic precoder for peak-to-average power ratio (PAPR) reduction. The physical-layer security during transmission is enhanced, where a huge key space is created by digital chaos...
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