Monolithic integration of a phase noise based quantum random number generator on InP platform

We present the experimental characterization of a fully integrated InP-based quantum random number generator chip composed from a single gain switched DBR laser and two Mach Zehnder interferometers. We demonstrate high degree of randomness by testing the QRNG output in the NIST Statistical Test Suite

High-performance end-to-end deep learning IM/DD link using optics-informed neural networks

: In this paper, we introduce optics-informed Neural Networks and demonstrate experimentally how they can improve performance of End-to-End deep learning models for IM/DD optical transmission links. Optics-informed or optics-inspired NNs are defined as the type of DL models that rely on linear and/or nonlinear building blocks whose mathematical description stems directly from the respective response of photonic devices, drawing their mathematical framework from neuromorphic photonic hardware developments and properly adapting their DL training algorithms. We investigate the application of an optics-inspired activation function that can be obtained by a semiconductor-based nonlinear optical module and is a variant of the logistic sigmoid, referred to as the Photonic Sigmoid, in End-to-End Deep Learning configurations for fiber communication links. Compared to state-of-the-art ReLU-based configurations used in End-to-End DL fiber link demonstrations, optics-informed models based on the Photonic Sigmoid show improved noise- and chromatic dispersion compensation properties in fiber-optic IM/DD links. An extensive simulation and experimental analysis revealed significant performance benefits for the Photonic Sigmoid NNs that can reach below BER HD FEC limit for fiber lengths up to 42 km, at an effective bit transmission rate of 48 Gb/s

Geotechnical Characterization of Fine-Grained Spoil Material from Surface Coal Mines

Coal mines produce large amounts of excavated waste soils, known as spoils. These materials can cover vast areas, are typically dumped in heaps without any treatment and are difficult to exploit for engineering purposes because of their significant variability. Efficient exploitation of spoil heaps poses engineering challenges, related mainly to the involved degree of uncertainty. A small number of studies have attempted to characterize the geotechnical properties of spoil material; however, there remains a considerable gap in understanding how to deal with spoil materials in the context of sustainable development and civil infrastructure design. In this work, a systematic effort is made to quantify the uncertainty of the geotechnical properties of a particular spoil heap. Laboratory test results based on an extended investigation of a spoil material originating from lignite coal mines are gathered in one database and thoroughly analyzed. The results reveal and quantify the significant spoil material variability, which is contrasted against data for common soils, while a systematic approach is proposed for spoil material characterization

3D Numerical Analysis for the Valorization Potential of Spoil Heaps by Shallow Foundations

Coal has been an energy source exploited for several decades, with its extraction being linked to creating wastes. Surface mines’ overburden and interburden materials are typically dumped in spoil heaps, many times without considering their future use. Nowadays, sustainability and circular economy principles demand the efficient valorization of these areas. In that vein, this work investigates alternatives from a geotechnical perspective with shallow foundations for the reclamation of a massive spoil heap. Initially, the installation with a raft foundation of a wind turbine was investigated through a serviceability limit envelope employing 3D finite element analysis. However, the spoil material is too soft to withstand such a massive superstructure, and more advanced foundation techniques are needed. Moreover, the installation of supportive constructions was examined, i.e., buildings with shallow isolated footings using a similar approach and 3D finite element analysis. The soil-footing response is much dependent on the constitutive model, and the potential of small buildings requires further attention. Overall, for the appropriate valorization of the spoil heap, it appears that ground improvement or deep foundations are necessary. This conclusion stands for many similar spoil heaps globally due to the material’s nature

Geotechnical Characterization of Fine-Grained Spoil Material from Surface Coal Mines

Coal mines produce large amounts of excavated waste soils, known as spoils. These materials can cover vast areas, are typically dumped in heaps without any treatment, and are difficult to exploit for engineering purposes because of their significant variability. Efficient exploitation of spoil heaps poses engineering challenges, related mainly to the involved degree of uncertainty. A small number of studies have attempted to characterize the geotechnical properties of spoil material; however, there remains a considerable gap in understanding how to deal with spoil materials in the context of sustainable development and civil infrastructure design. In this work, a systematic effort is made to quantify the uncertainty of the geotechnical properties of a particular spoil heap. Laboratory test results based on an extended investigation of a spoil material originating from lignite coal mines are gathered in one database and thoroughly analyzed. The results reveal and quantify the significant spoil material variability, which is contrasted against data for common soils, while a systematic approach is proposed for spoil material characterization.This material may be downloaded for personal use only. Any other use requires prior permission of the American Society of Civil Engineers. This material may be found at https://ascelibrary.org/doi/10.1061/%28ASCE%29GT.1943-5606.0002550

Long term experimental verification of a single chip quantum random number generator fabricated on the InP platform

This work presents the results from the experimental evaluation of a quantum random number generator circuit over a period of 300 minutes based on a single chip fabricated on the InP platform. The circuit layout contains a gain switched laser diode (LD), followed by a balanced Mach Zehnder Interferometer for proper light power distribution to the two arms of an unbalanced MZI incorporating a 65.4 mm long spiral waveguide that translates the random phase fluctuations to power variations. The LD was gain-switched at 1.3 GHz and the chip delivered a min-entropy of 0.5875 per bit after removal of the classical noise, resulting a total aggregate bit rate of 6.11 Gbps. The recoded data set successfully passed the 15-battery test NIST statistical test suite for all data sets

480 Gbps WDM Transmission Through an Al2O3:Er3+ Waveguide Amplifier

The increasing need for more efficient communication networks has been the main driving force for the development of complex photonic integration circuits combining active and passive building blocks towards advanced functionality. However, this perpetual effort comes with the cost of additive power losses and the research community has resorted to the investigation of different materials to establish efficient on chip amplification. Among the different proposals, erbium doped waveguide amplifiers appear to be a promising solution for high performance transmission in the C-band band with low fabrication cost, due to their CMOS compatibility and integration potential with the silicon\silicon nitride photonic platforms. In this paper we provide a holistic study for high-speed WDM transmission capabilities of a monolithically integrated Al2O3:Er3+ spiral waveguide amplifier co-integrated with Si3N4 components, providing a static characterization and a dynamic evaluation for (a) 440 Gbps, (b) 840 Gbps and (c) 860 Gbps WDM transmissions achieving clearly open eye diagram in all cases. The active region of the erbium doped waveguide amplifier consists of a 5.9 cm Al2O3:Er3+ spiral adiabatically coupled to passive Si3N4 waveguides combined with on chip 980 nm/1550 nm WDM Multiplexers/Demultiplexers. Experimental results reveal bit error rate values below the KR4 FEC limit of 210-5 for all channels, without any DSP applied on the transmitter or receiver side for a 440 Gbps and 840 Gbps data stream transmission