This study addresses the issues of geographical distance and security vulnerability in conventional PONs during broadcast downlink transmission. We experimentally demonstrated that IQ-imbalanced and phase-encrypted 4ASK downlink transmission between two ONU groups, separated by a distance of 10 km, can achieve highly secure point-to-multipoint communication.
A thermal RC-network is presented for compact modelling of self-heating in a Si photonic ring modulator. The model captures the non-linear thermo-optical dynamics at low frequencies (<1 GHz), and accurately reproduces nanosecond-scale variations in optical transmission as observed in experiments.
We investigate the theoretical properties of a novel all-optical switch design consisting of a saturable absorber in an add-drop ring resonator. Using a modified transfer matrix method we demonstrate nonvolatile switching, where the routing persists even after the control signal is deactivated.
Photonic hardware represents a promising alternative to speed-up Neural Network (NN) computations, outperforming electronic counterparts in terms of speed, energy consumption and computing density. In this paper we exploit a Photonic-Aware Neural Network (PANN) architecture with unipolar and bipolar weight implementations, considering ReLU and photonic sigmoid as candidate activation functions to solve a heartbeat sound classification task. Results indicate that increasing the bitwidths during quantization improves the F1-score. The use of bipolar implementation for weight choice demonstrates better performance. ReLU is identified as a better nonlinearity. Finally, a multi-resolution scenario in the bipolar photonic-sigmoid experiment is evaluated, revealing that incorporating multi-resolution does not enhance the model's generalization ability if the bitwidth for the first layer remains fixed. However, the importance of the highest bitwidth at the NN inputs is highlighted.
We introduce the concept of GTE-assisted double-pass MZI and its operation using photon number states, based on quantum-optical formalism. We also theoretically show impressive interferometric fringes for different combinations of N-photon states as circuit inputs.
We derive the information-theoretic limit to phase-shift efficiency of universal multiport interferometers, and propose an architecture that approaches this limit to within a factor of 2×, approximately a 10× improvement over the prior art.
We designed a DRL-based routing, modulation, spectrum, and core assignment algorithm to fully exploit the core switching capabilities of space division multiplexing networks with multi-core fibres. The proposed method shows up to 53% better blocking probability performance compared to RMSCA benchmarks in different traffic loads.
The eigenvalue of the eigenvalue equation associated to the nonlinear Schrödinger equation is constant regardless of the propagation distance, so it's an ideal information carrier that is not affected by the dispersion and the nonlinearity of optical fiber. For this reason, optical eigenvalue modulation has been proposed as a communication method using eigenvalues. However, the eigenvalue is affected by bandwidth limitation of the receiver and the sampling rate for demodulating eigenvalues. In this paper, we analyze the influence of bandwidth limitation on eigenvalues by theoretical analysis and show that the result is consistent with the results obtained by computer simulation and experiment.
The training process of a feed-forward neural network is typically power- and time-consuming because it requires optimization of the output response through a gradient descent algorithm. An alternative to these approaches is the extreme learning machine, which is a feed-forward neural network composed of a single hidden layer in which training occurs only in the readout. Here, we propose and experimentally validate an extreme learning machine architecture based on an array of 18 silicon microresonators. We provide a proof-of-concept demonstration of the network by solving the nonlinear logic operation XOR, the iris flower classification, and banknote authentication.
We propose a novel Spatially-Diverse Point-to-MultiPoint (SDPtMP) approach for the fronthaul, utilizing sharp interleaver filter network instead of traditional splitters. This approach leads to distribution of subcarrier groupings from multiple sources to each antenna site in lossless fashion, offering enhanced functionality and higher energy efficiency as it eliminates the need for signal amplification which complements splitters-based architectures. The proposed architecture enables diverse connectivity among multiple Radio Units of a Radio Access Network through spatial, wavelength and subcarrier degrees of networking. According to the simulation results conducted in this study, the optimal values for the subcarrier baud rate is within the range of 3.125 GHz to 3.5 GHz, when spaced at 4 GHz and confined within the sharp interleavers. The proposed architecture offers an overall capacity of 336Gbps per wavelength and spatial dimension.
A digital model of a dual-polarization IQ ultra-wideband indium phosphide Mach-Zehnder modulator is obtained through machine learning techniques. The model is used to test optimization algorithms that automatically set the modulator control voltages under different operative conditions finding the optimum bias point. ©2023 The Author(s)
We propose an ultra-compact silicon photonics (SiPh) crossbar chip for implementing optical pass-through (OPT) links for high performance computing applications. We conduct high-speed measurements for a single-wavelength OPT link and evaluate the bit error rate performance from 8 Gbps to 32 Gbps under the effect of an aggressor channel as well.
A line controller architecture for partially disaggregated optical networks is presented, providing automation and interoperability in the use of multi-vendor equipment. Downstream of the architectural definition, the results obtained in an implementation operated on experimental equipment are shown regarding the functioning of the designed interfaces.
In resource allocation in space-division multiplexing elastic optical networks with multi-core fibers (MCFs), indirect inter-core crosstalk (IC-XT) has been ignored because of being negligible. However, in very dense MCFs, there is a potential concern that the indirect XT may become non-negligible. We propose a new IC-XT evaluation method considering the indirect IC-XT. Simulation results demonstrate that the performance of the conventional core prioritization scheme can be negatively affected by the indirect IC-XT in some cases. Furthermore, we indicate the conditions under which the indirect IC-XT is negligible.
Programmable unitary converters are powerful tools for realizing unitary transformations, advancing fields of computing and communication. The accuracy of these unitary transformations is crucial for maintaining high fidelity in such applications. However, various physical artifacts can impair the accuracy of the synthesized transformations. A commonly employed approach uses the system's gradient to restore accuracy. Although this gradient can indeed be physically measured using external equipment, it leads to a rather complex optical system. In this study, we propose a standalone method for measuring matrix norm gradients, where `standalone' means that no additional optical equipment is needed. This method is based on the mathematical fact that the central difference, which is generally used for the approximation of differentiation, can yield exact differentiation for any unitary transformer. Furthermore, we introduce a new matrix distance that is suitable for optimizing unitary converters which use intensity detectors at the output. Numerical analysis demonstrates that our method exhibits orders of magnitude higher tolerance to measurement noise than prior similar approaches.
In bufferless Optical packet switching (OPS) network, packet loss occurs when multiple packets arrive at the output port in relay node at the same timing even if there is no congestion. We propose a novel paradigm of transport protocol which has mechanism to autonomously control the burst transmission timing and interval. Differently from a large number of conventional modifications of TCP, such as congestion avoidance mechanisms, window control mechanisms, pacing mechanisms and so on, our proposal completely keeps burst packets transfer every constant time interval determined in a per-flow stepwise manner. Extensive simulation results confirmed that our proposal attains more than 7.0 times larger network throughput compared to conventional TCP.
In this paper, we present a compact and efficient structure designed to extract optical output from a multimode waveguide (MMW), which facilitates the propagation of multiple waveguide modes. Our focus is on its application in reservoir computing systems. Through extensive simulations and parameter adjusting, we demonstrate that the average loss across all guided modes can be effectively reduced to as low as 0.3 dB. Our proposed structure is specifically designed for a 25 μm wide MMW implemented on a silicon photonics platform.
This paper proposes a fast and nondisruptive reconfiguration algorithm for topology migration in optical datacom networks. The proposed algorithm models the dependency between links to be removed as conflict graphs (CGs) and jointly optimizes the reconfiguration speed and traffic disruption by iteratively solving the maximum clique problems with the CGs. Numerical results show that the proposed algorithm can reduce the number of disrupted connections by ×74.5 with just 2.7 more reconfiguration stages on average compared with a baseline performing one-shot reconfiguration.
We propose a new concept of high-capacity WDM transmitter with 8-wavelength laser sources, 8 semiconductor optical amplifiers, and 128 x 112-Gb/s PAM4 micro-ring modulators, potentially a bandwidth of up to 12.8 Tb/s within the footprint of 8 mm 2 by suppressing SOA-induced nonlinearities.
This paper presents viable solutions for the control of a multi-band optical network. NETCONF and augmented OpenConfig YANG data models are adopted to configure and monitor the state of network devices. Both connection provisioning and Quality of transmission estimation account for Stimulated Raman Scattering.
