Query: optical reservoir for communications

Candidate papers:

abstract: During the last decade reservoir computing (RC) has proven to be a powerful machine learning concept using recurrent networks to process sequential information streams [1] Lately, the concept of RC was drastically simplified to reduce hardware requirements, thus making machine learning concepts more obtainable to apply in actual physical systems [2] RC has been implemented in photonic configurations and has efficientiy processed analog optical signals following simple schemes and minimal training overhead. Especially the realization using a semiconductor laser with time delayed optical feedback has shown the potential of all optical machine learning, utilizing signals with transient states at the GHz regime [3]
author_names: Apostolos Argyris

Julian Bueno

Miguel C Soriano

Inga Fischerv
title: Improving detection in optical communications using all optical reservoir computing
venue: 2017 Conference on Lasers and Electro Optics Europe European Quantum Electronics Conference (CLEO/Europe EQEC)
year: 2017

abstract: The cloud edge data center will enable reliable and low latency options for the network, and the interconnection among these data centers will demand a scalable low complexity scheme. An intensity modulated and directed detected transmission system is an attractive solution, but chromatic dispersion is the main limitation for higher symbol rate systems. To overcome this challenge, we have proposed and experimentally demonstrated a receiver with shared complexity between optical and digital domains that enables 80 km transmission reach below KP4 FEC limit for a 32 GBd on off keying signal. The optical stage consists of optical filters that slices the signal into smaller sub bands and each is detected by a photodetector. A feedforward neural network and reservoir computing are compared to reconstruct the full signal from the slices and mitigate the chromatic dispersion. Both equalizers have shown similar performance with the advantage of the reservoir computing requiring fewer inputs and easier training process. In this work, we have compared the linear and nonlinear activation functions in the feedforward neural network to investigate the gain of using a nonlinear equalizer. The maximum transmission reach is reduced almost to half, \approx$45 km, when using the linear. The performance is also reduced if a reduced number of slices is used in the receiver, as we have demonstrated. In this case, using 2 slices to reduce the complexity of the system, instead of the total 4, we have shown a \approx$55 km transmission reach below KP4 FEC limit. In this work we have also provided a numerical comparison with 4x8 GBd subcarriers system. The results have shown a 40 km increase in transmission reach compared to the proposed optoelectronic system. The trade off between performance and complexity should be analyzed for each case, as a different hardware is required in each situation.
author_names: Stenio M Ranzini

Roman Dischler

Francesco Da Ros

Henning Bulow

Darko Zibar
title: Experimental Investigation of Optoelectronic Receiver With Reservoir Computing in Short Reach Optical Fiber Communications
venue: Journal of Lightwave Technology
year: 2021

abstract: An opto electronic reservoir computer based on a light valve, multimode fiber speckle, and a camera combined with back end signal processing experimentally performs blind signal classification for return to zero and non return to zero communications signals at low signal to noise ratio.
author_names: Marta Luengo-Kovac

Uttam Paudel

T Justin Shaw

George C Valley
title: Speckle Based Optical Waveguide Reservoir Computer for Blind Signal Classification
venue: 2020 Conference on Lasers and Electro Optics (CLEO)
year: 2020

abstract: We present the design and numerical study of a nonlinear equalizer for optical communications based on silicon photonics and reservoir computing. The proposed equalizer leverages the optical information processing capabilities of integrated photonic reservoirs to combat distortions both in metro links of a few hundred kilometers and in high speed short reach intensity modulation direct detection links. We show nonlinear compensation in unrepeated metro links of up to 200 km that outperform electrical feedforward equalizers based equalizers, and ultimately any linear compensation device. For a high speed short reach 40 Gb/s link based on a distributed feedback laser and an electroabsorptive modulator, and considering a hard decision forward error correction limit of $0.2 \times 10^ 2} we can increase the reach by almost 10 km. Our equalizer is compact (only 16 nodes) and operates in the optical domain without the need for complex electronic DSP, meaning its performance is not bandwidth constrained. The approach is, therefore, a viable candidate even for equalization techniques far beyond 100G optical communication links.
author_names: Andrew Katumba

Xin Yin

Joni Dambre

Peter Bienstman
title: A Neuromorphic Silicon Photonics Nonlinear Equalizer For Optical Communications With Intensity Modulation and Direct Detection
venue: Journal of Lightwave Technology
year: 2019

abstract: Machine learning techniques have proven very efficient in assorted classification tasks. Nevertheless, processing time dependent high speed signals can turn into an extremely challenging task, especially when these signals have been nonlinearly distorted. Recently, analogue hardware concepts using nonlinear transient responses have been gaining significant interest for fast information processing. Here, we introduce a simplified photonic reservoir computing scheme for data classification of severely distorted optical communication signals after extended fibre transmission. To this end, we convert the direct bit detection process into a pattern recognition problem. Using an experimental implementation of our photonic reservoir computer, we demonstrate an improvement in bit error rate by two orders of magnitude, compared to directly classifying the transmitted signal. This improvement corresponds to an extension of the communication range by over 75% While we do not yet reach full real time post processing at telecom rates, we discuss how future designs might close the gap.
author_names: Apostolos Argyris

Julian Bueno

Ingo Fischer
title: Photonic machine learning implementation for signal recovery in optical communications
venue: Scientific Reports
year: 2018

abstract: A novel approach to achieving ultrafast real time user localization in optically controlled beam steering wireless communications (OWC) is proposed and demonstrated in this letter. Ultrafast wavelength encoded user localization at 50 MHz rate is achieved based on photonic time stretch concept and a passive beam scanner using a 45deg tilted fibre grating (TFG) Not only the angular separation but also the linear distance from the access point can be determined simultaneously. More importantly, challenging instantaneous optical wavelength identification within nanosecond range is successfully achieved through chirped microwave frequency encoding and reservoir computing (RC) based frequency identification. A proof of concept experiment was carried out to verify the proposed approach. The results show that RC is more efficient in frequency chirp identification than the conventional short time Fourier transform approach.
author_names: Chaitanya Kumar Mididoddi

Ning Jing
title: Reservoir Computing Assisted Ultrafast User Localization in Beam Steering Optical Wireless System
venue: IEEE Photonics Technology Letters
year: 2021

abstract: Photonic reservoir computing (RC) enables us to introduce artificial neural networks (ANNs) as a deployable hardware based processing unit beyond the von Neumann architecture. Its unique approach to consider only the output layer weights as adaptive, reduces training complexity and enables the use of ANNs in time sensitive areas like optical communications. In this paper, we numerically investigate and evaluate the requirements of a photonic RC using an active silicon micro ring resonator as a photonic integrated circuit (PIC) based reservoir system to compensate for transmission impairments such as chromatic dispersion and nonlinear effects occurring in optical transmission systems. We compare the performance of this RC with results from digital signal processing using Kramers Kronig reception of distorted PAM 4 symbols from a 56 GBaud WDM transmission experiment over 100 km uncompensated SSMF.
author_names: Shi Li

Sourav Dev

Sebastian Kuhl

Kambiz Jamshidi

Stephan Pachnicke
title: Micro Ring Resonator Based Photonic Reservoir Computing for PAM Equalization
venue: IEEE Photonics Technology Letters
year: 2021

abstract: Detection of wideband RF signals has applications in sensing and communications. When the signals of interest are sparse, compressive sensing (CS) provides a sub Nyquist sampling strategy with potential size, weight, and power savings. The critical element in a CS receiver is the device that produces the wideband CS measurement matrix (MM) a MxN matrix with M N satisfying certain properties [1] We have shown that passive optical speckle in multimode waveguides provides excellent MMs for CS. The M rows of the MM are obtained from M photodetectors placed at different locations within the output speckle pattern. A range of algorithms can be used to recover the sparse input signal from the resulting measurement vector. We have experimentally demonstrated two speckle based CS systems: (1) a real time system with M 16 implemented using multimode fiber (MMF) that recovers RF frequency, amplitude, and phase, and (2) a simplified spectrometer system implemented using a multimode planar waveguide on a silicon photonic chip that detects only RF frequency and amplitude.
author_names: George A Sefler

Uttam Paudel

T Justin Shaw

Daniele M Monahan

Adam C Scofield

S Estella

Leif A Johansson

George C Valley
title: Laser Speckle in Multimode Waveguides for Random Projections in Compressive Sensing and Reservoir Computing
venue: 2019 IEEE Photonics Conference (IPC)
year: 2019

abstract: It is well known that optical feedback in a laser system, such as the semiconductor laser based one shown schematically in fig.1, can either stabilise or destabilise its output power and spectral characteristics. Semiconductor lasers have a level of sensitivity to optical feedback that is far greater than most lasers [1 3] The current interest in using semiconductor laser with optical feedback systems, including versions implemented as integrated devices, in, for example, random number generation, reservoir computing and secure communications [1 3] sustains vigorous research activity in the field. The high, and increasing, potential for making strong connections between the predictions of increasingly sophisticated theoretical models of these complex systems and experimental measurements also reinforces the sustained activity in the field.
author_names: Mindaugas Radziunas

Douglas J Little

Deborah M Kane
title: A new approach to modelling the coherence of optical feedback in dynamical semiconductor laser systems
venue: 2018 Conference on Optoelectronic and Microelectronic Materials and Devices (COMMAD)
year: 2018

abstract: Micro pixelated InGaN LED arrays operating at 560 and 600 nm, respectively, are demonstrated for what the authors believe to be the first time. Such devices offer applications in areas including bioinstrumentation, visible light communications and optoelectronic tweezers. The devices reported are based on new epitaxial structures, retaining conventional (0 0 0 1) orientation, but incorporating electron reservoir layers which enhance the efficiency of radiative combination in the active regions. A measured output optical power density up to 8 W cm 2 (4.4 W cm 2) has been achieved from a representative pixel of the yellow green (amber) LED array, substantially higher than that from conventional broad area reference LEDs fabricated from the same wafer material. Furthermore, these micro LEDs can sustain a high current density, up to 4.5 kA cm 2, before thermal rollover. A significant blueshift of the emission wavelength with increasing injection current is observed, however. This blueshift saturates at 45 nm (50 nm) for the yellow green (amber) LED array, and numerical simulations have been used to gain insight into the responsible mechanisms in this microstructured format of device. In the relatively low current density regime <3.5 kA cm 2) the blueshift is attributable to both the screening of the piezoelectric field by the injected carriers and the band filling effect, whereas in the high current regime, it is mainly due to band filling. Further development of the epitaxial wafer material is expected to improve the current dependent spectral stability.
author_names: Zheng Gong

N Y Liu

Yadong Tao

David Massoubre

Enyuan Xie

Xiaodong Hu

Zi Zhen Chen

G Y Zhang

Y B Pan

M S Hao

Ian M Watson

Erdan Gu

Martin D Dawson
title: Electrical, spectral and optical performance of yellow green and amber micro pixelated InGaN light emitting diodes
year: 2012