D. Apostolopoulos

0.48Tb/s (12x40Gb/s) WDM transmission and high-quality thermo-optic switching in dielectric loaded plasmonics

We demonstrate Wavelength Division Multiplexed (WDM)-enabled transmission of 480Gb/s aggregate data traffic (12x40Gb/s) as well as high-quality 1x2 thermo-optic tuning in Dielectric-Loaded Surface Plasmon Polariton Waveguides (DLSPPWs). The WDM transmission characteristics have been verified through BER measurements by exploiting the heterointegration of a 60 μm-long straight DLSPPW on a Silicon-on-Insulator waveguide platform, showing error-free performance for six out of the twelve channels. High-quality thermo-optic tuning has been achieved by utilizing Cycloaliphatic-Acrylate-Polymer as an efficient thermo-optic polymer loading employed in a dual-resonator DLSPPW switching structure, yielding a 9 nm wavelength shift and extinction ratio values higher than 10 dB at both output ports when heated to 90°C.

All-optical 3-bit counter using two cascaded stages of SOA-MZI-based T-flip-flops

We present a 3-bit all-optical counter comprising two cascaded stages of a novel optical T-Flip-Flop that employs one SOA-MZI and a feedback loop. Experimental verification is demonstrated at 8MHz using a fiber-based feedback loop implementation.

Agile photonic integrated systems-on-chip enabling WDM terabit networks

The ICT-APACHE research project is focusing on the development of cost-effective, compact, scalable and agile integrated components capable of generating, regenerating and receiving multi-level encoded data signals for high capacity (>100 Gb/s) WDM optical networks. APACHE technology relies on InP active, monolithic chips, hybridly integrated on silica-on-silicon planar lightwave platforms in order to achieve cost-efficiency, high yield, low power consumption and device scaling beyond the level commercially available today. The APACHE integration approach is implemented in a two-dimensional plan, horizontally and vertically, in order to enable multi-functionality and increased capacity, respectively. The final goal of the APACHE project is the fabrication of integrated arrays of transmitters, receivers and regenerators that will operate with 100 Gb/s OOK, DPSK and DQPSK modulated signals, allowing for 1 Terabit/s on-chip capacity. In this paper, we will review the latest results from the system-level characterization of the developed components and will outline the roadmap for future endeavours.

40-Gb/s 3R Burst Mode Regenerator Using Four Integrated MZI Switches

We demonstrate an all-optical 3R burst mode regenerator operating error-free with 40-Gb/s data packets. It is comprised of a sequence of four hybridly integrated semiconductor optical amplifier Mach-Zehnder interferometric switches and is shown to operate with short, variable length and asynchronous data packets, with a dynamic range of 9.3 dB

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.

Packet-level synchronization scheme for optical packet switched network nodes

We demonstrate an all-optical, self-synchronization scheme for optical packet switched network nodes. It provides both the packet clock signal and the packet beginning, marker pulse. The circuit uses two hybridly integrated MZI switches and has been evaluated with synchronous, asynchronous and variable length, data packets at 10 Gb/s. It is compact and requires relatively low energies to operate.

40 Gb/s NRZ wavelength conversion with enhanced 2R regeneration characteristics using a differentially-biased SOA-MZI switch

We present error-free 40 Gb/s NRZ signal wavelength conversion with a differential biasing scheme in a SOA-Mach Zehnder interferometer. Experimental performance analysis shows 1.7 dB negative power penalty and enhanced 2R regenerative characteristics.

Packet clock recovery at 40 Gb/s and beyond, using a Fabry-Pérot filter and an optical power limiter based on a bismuth oxide fibre

In the present paper, the authors demonstrated successful CR from short optical packets at 40 Gb/s, using a recently introduced technique that allows in principle for operation at ultra-high bit rates far beyond 40 Gb/s. The technique is based on the previously reported scheme that uses a Fabry-Perot Filter (FPF) for producing a clock resembling signal, followed by an optical power limiter in order to remove the strong peak power variation of the FPFs output, and thus provide a clock signal of high quality. Unlikely to the previous implementations of the scheme, the power limiting functionality is not based on semiconductor-based devices, but rather on the use of a nonlinear fiber, erasing in principle any operational bit rate limitations of the scheme.

Field-trial demonstration of an extended-reach GPON-supporting 60-GHz indoor wireless access

The 5G era is nearly upon us, and poses several challenges for system designers; one important question is how the (soon to be standardized) mmWave bands of wireless mobile access can coexist harmoniously with optical links in fixed telecom networks. To this end, we present a Radio-over-Fiber (RoF) backhauling concept, interfaced to a 60-GHz indoor femto-cell via a field-installed optical fiber link. We successfully demonstrate generation of a RoF signal up to 1 Gb/s and transmit it optically over 43 km of deployed Single Mode Fiber (SMF), as well as investigate the performance of the 60-GHz access link as a function of distance. The optical link introduces negligible degradation, contrasting the effect of multipath fading in the 60-GHz wireless channel; the latter requires adaptive equalization using offline DSP. The proposed scheme is further validated by demonstration of a 60-GHz Remote Antenna Unit (RAU) concept, handling real traffic from commercial Gigabit Passive Optical Network (GPON) equipment. Proper RAU operation at 1.25 Gb/s is achieved, accommodating true data packets from a Media Converter emitting at 1310 nm through an in-building fiber link. System performance is confirmed through Bit Error Rate (BER) and Error Vector Magnitude (EVM) measurements. EVMs of ~11 and 19% are achieved with BPSK signals, for distances of 1 and 2 m respectively. As standardization of mmWave technologies moves from 5G testbeds to field-trial prototypes, successful demonstration of such 60-GHz wireless access scenarios over a telecom operator’s commercial fiber infrastructure is even more relevant.

Eight-channel second-order ring resonator based SOI multiplexers/demultiplexers for optical interconnects

We demonstrate two 8×1 silicon ring-based multiplexers for dual stream multiplexing. All resonances were thermo-optically tuned and spaced by 100GHz having >40GHz bandwidth. Error-free performance without significant signal degradation was obtained for two 4-channel streams at 10Gb/s.