1
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Peng Y, Liu S, Kovanis V, Wang C. Uniform spike trains in optically injected quantum cascade oscillators. CHAOS (WOODBURY, N.Y.) 2023; 33:123127. [PMID: 38127292 DOI: 10.1063/5.0177896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023]
Abstract
It has been experimentally and theoretically analyzed that noise-induced excitability in quantum well and quantum dot semiconductor laser systems usually produces sharp spike patterns of non-uniform amplitude. In this paper, we experimentally record that a quantum cascade oscillator injected externally with a monochromatic laser beam exhibits a series of highly uniform spike trains, which occur in the proximity of the saddle-node bifurcation. Theoretical analysis based on a properly designed single-mode rate equation model endowed with quantum noise reveals that this high uniformity has its primary origin in the ultrashort carrier lifetime of the quantum cascade laser gain medium that is typically close to 1 ps.
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Affiliation(s)
- Yibo Peng
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Siting Liu
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Engineering Research Center of Energy Efficient and Custom AI IC, ShanghaiTech University, Shanghai 201210, China
| | - Vassilios Kovanis
- Virginia Tech, Virginia Tech Research Center in Arlington VA, 900 N Glebe Rd, Arlington, Virginia 22203, USA
| | - Cheng Wang
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Engineering Research Center of Energy Efficient and Custom AI IC, ShanghaiTech University, Shanghai 201210, China
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2
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Dillane M, Viktorov EA, Kelleher B. Refractory times for excitable dual-state quantum dot laser neurons. Phys Rev E 2023; 107:034216. [PMID: 37073058 DOI: 10.1103/physreve.107.034216] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/17/2023] [Indexed: 04/20/2023]
Abstract
Excitable photonic systems show promise for ultrafast analog computation, several orders of magnitude faster than biological neurons. Optically injected quantum dot lasers display several excitable mechanisms with dual-state quantum lasers recently emerging as true all-or-none excitable artificial neurons. For use in applications, deterministic triggering is necessary and this has previously been demonstrated in the literature. In this work we analyze the crucially important refractory time for this dual-state system, which defines the minimum time between distinct pulses in any train.
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Affiliation(s)
- M Dillane
- School of Physics, University College Cork, T12 K8AF Cork, Ireland
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, T12 R5CP Cork, Ireland
- Centre for Advanced Photonics and Process Analysis, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| | - E A Viktorov
- ITMO University, 197101 Saint Petersburg, Russia
- Ioffe Institute, 194021 Saint Petersburg, Russia
| | - B Kelleher
- School of Physics, University College Cork, T12 K8AF Cork, Ireland
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, T12 R5CP Cork, Ireland
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3
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Dillane M, Viktorov EA, Kelleher B. Inhibitory and excitatory integration with a quantum dot laser neuron. OPTICS LETTERS 2023; 48:21-24. [PMID: 36563358 DOI: 10.1364/ol.475805] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 11/20/2022] [Indexed: 06/17/2023]
Abstract
Neuromorphic computing has garnered a lot of attention in recent years. Excitable photonic systems in particular demonstrate great potential for ultrafast, controllable spike processing. Optically injected quantum dot lasers display several distinct excitable regimes. We demonstrate here that optically injected dual-state quantum dot lasers can display the classic leaky integrate-and-fire mechanism where the integration of several sub-threshold perturbations can yield an effective supra-threshold perturbation. Intriguingly, a contrasting integrate-and-inhibit mechanism is demonstrated in this work where the integration of two supra-threshold perturbations yields an effective sub-threshold perturbation similar to the pre-pulse inhibition mechanism of biological neurons. This is the first such mechanism in neuromorphic photonics to the best of our knowledge.
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4
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Tamura M, Morison H, Shastri BJ. Inducing optical self-pulsation by electrically tuning graphene on a silicon microring. NANOPHOTONICS 2022; 11:4017-4025. [PMID: 36081448 PMCID: PMC9394513 DOI: 10.1515/nanoph-2022-0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
A mechanism for self-pulsation in a proposed graphene-on-silicon microring device is studied. The relevant nonlinear effects of two photon absorption, Kerr effect, saturable absorption, free carrier absorption, and dispersion are included in a coupled mode theory framework. We look at the electrical tunability of absorption and the Kerr effect in graphene. We show that the microring can switch from a stable rest state to a self-pulsation state by electrically tuning the graphene under constant illumination. This switching is indicative of a supercritical Hopf bifurcation since the frequency of the pulses is approximately constant at 7 GHz and the amplitudes initial grow with increasing Fermi level. The CMOS compatibility of graphene and the opto-electronic mechanism allows this to device to be fairly easily integrated with other silicon photonic devices.
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Affiliation(s)
- Marcus Tamura
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Canada
| | - Hugh Morison
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Canada
| | - Bhavin J. Shastri
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Canada
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5
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Peng YB, Zhao BB, Wang C. Nonlinear dynamics of a quantum cascade laser with optical injection. OPTICS EXPRESS 2022; 30:27593-27601. [PMID: 36236927 DOI: 10.1364/oe.459225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/10/2022] [Indexed: 06/16/2023]
Abstract
This work presents the nonlinear dynamics of a quantum cascade laser subject to optical injection. Within the stable locking regime, the optical power shows a hysteresis behavior as a function of the detuning frequency. Outside the stable locking regime, the laser mostly produces periodic oscillations. However, the laser pumped at a high pump current also generates spiking pulsations with uniform amplitude, which occur in the vicinity of the negative locking boundary.
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6
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Mapping the Stability and Dynamics of Optically Injected Dual State Quantum Dot Lasers. PHOTONICS 2022. [DOI: 10.3390/photonics9020101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Optical injection is a key nonlinear laser configuration both for applications and fundamental studies. An important figure for understanding the optically injected laser system is the two parameter stability mapping of the dynamics found by examining the output of the injected laser under different combinations of the injection strength and detuning. We experimentally and theoretically generate this map for an optically injected quantum dot laser, biased to emit from the first excited state and optically injected near the ground state. Regions of different dynamical behaviours including phase-locking, excitability, and bursting regimes are identified. At the negatively detuned locking boundary, ground state dropouts and excited state pulses are observed near a hysteresis cycle for low injection strengths. Higher injection strengths reveal μs duration square wave trains where the intensities of the ground state and excited state operate in antiphase. A narrow region of extremely slow oscillations with periods of several tens of milliseconds is observed at the positively detuned boundary. Two competing optothermal couplings are introduced and are shown to reproduce the experimental results extremely well. In fact, the dynamics of the system are dominated by these optothermal effects and their interplay is central to reproducing detailed features of the stability map.
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Kelleher B, Dillane M, Viktorov EA. Optical information processing using dual state quantum dot lasers: complexity through simplicity. LIGHT, SCIENCE & APPLICATIONS 2021; 10:238. [PMID: 34840328 PMCID: PMC8628007 DOI: 10.1038/s41377-021-00670-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 09/03/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
We review results on the optical injection of dual state InAs quantum dot-based semiconductor lasers. The two states in question are the so-called ground state and first excited state of the laser. This ability to lase from two different energy states is unique amongst semiconductor lasers and in combination with the high, intrinsic relaxation oscillation damping of the material and the novel, inherent cascade like carrier relaxation process, endows optically injected dual state quantum dot lasers with many unique dynamical properties. Particular attention is paid to fast state switching, antiphase excitability, novel information processing techniques and optothermally induced neuronal phenomena. We compare and contrast some of the physical properties of the system with other optically injected two state devices such as vertical cavity surface emitting lasers and ring lasers. Finally, we offer an outlook on the use of quantum dot material in photonic integrated circuits.
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Affiliation(s)
- Bryan Kelleher
- Department of Physics, University College Cork, Cork, Ireland.
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland.
| | - Michael Dillane
- Department of Physics, University College Cork, Cork, Ireland
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
- Centre for Advanced Photonics & Process Analysis, Munster Technological University, Bishopstown, Cork, T12 P928, Ireland
| | - Evgeny A Viktorov
- National Research University of Information Technologies, Mechanics and Optics, Kronverksky Pr. 49, St. Petersburg, 197101, Russia
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8
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Crnjanski J, Krstić M, Totović A, Pleros N, Gvozdić D. Adaptive sigmoid-like and PReLU activation functions for all-optical perceptron. OPTICS LETTERS 2021; 46:2003-2006. [PMID: 33929404 DOI: 10.1364/ol.422930] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
We present an approach for the generation of an adaptive sigmoid-like and PReLU nonlinear activation function of an all-optical perceptron, exploiting the bistability of an injection-locked Fabry-Perot semiconductor laser. The profile of the activation function can be tailored by adjusting the injection-locked side-mode order, frequency detuning of the input optical signal, Henry factor, or bias current. The universal fitting function for both families of the activation functions is presented.
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9
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Prants WT, Bonatto C. Triple point of synchronization, phase singularity, and excitability along the transition between unbounded and bounded phase oscillations in a forced nonlinear oscillator. Phys Rev E 2021; 103:032201. [PMID: 33862802 DOI: 10.1103/physreve.103.032201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 02/08/2021] [Indexed: 11/07/2022]
Abstract
We report the discovery of a codimension-two phenomenon in the phase diagram of a second-order self-sustained nonlinear oscillator subject to a constant external periodic forcing, around which three regimes associated with the synchronization phenomenon exist, namely phase-locking, frequency-locking without phase-locking, and frequency-unlocking states. The triple point of synchronization arises when a saddle-node homoclinic cycle collides with the zero-amplitude state of the forced oscillator. A line on the phase diagram where limit-cycle solutions contain a phase singularity departs from the triple point, giving rise to a codimension-one transition between the regimes of frequency unlocking and frequency locking without phase locking. At the parameter values where the critical transition occurs, the forced oscillator exhibits a separatrix with a π phase jump, i.e., a particular trajectory in phase space that separates two distinct behaviors of the phase dynamics. Close to the triple point, noise induces excitable pulses where the two variants of type-I excitability, i.e., pulses with and without 2π phase slips, appear stochastically. The impacts of weak noise and some other dynamical aspects associated with the transition induced by the singular phenomenon are also discussed.
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Affiliation(s)
- Willian T Prants
- Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Brazil
| | - Cristian Bonatto
- Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Brazil
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10
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Dillane M, Lingnau B, Viktorov EA, Dubinkin I, Fedorov N, Kelleher B. Asymmetric excitable phase triggering in an optically injected semiconductor laser. OPTICS LETTERS 2021; 46:440-443. [PMID: 33449048 DOI: 10.1364/ol.410085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
One of the defining characteristics of excitability is the existence of an excitable threshold: the minimum perturbation amplitude necessary to produce an excitable response. We analyze an optically injected dual state quantum dot laser, previously shown to display a dual state stochastic excitable dynamic. We show that deterministic triggering of this dynamic can be achieved via optical phase perturbations. Further, we demonstrate that there are in fact two asymmetric excitable thresholds in this system corresponding to the two possible directions of optical phase perturbations. For fast enough perturbations, an excitable interval arises, and there is a limit to the perturbation amplitude, above which excitations no longer arise, a phenomenon heretofore unobserved in studies of excitability.
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11
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Chen YF, Lee CC, Hsiao JQ, Huang HY, Tsou CH, Liang HC, Huang KF. Exploiting a monolithic passively Q-switched Nd:YAG laser to mimic a single neuron cell under periodic stimulation. OPTICS LETTERS 2020; 45:4032-4035. [PMID: 32667347 DOI: 10.1364/ol.399253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/20/2020] [Indexed: 06/11/2023]
Abstract
A monolithic passively Q-switched Nd:YAG laser under periodic pulse pumping is originally exploited to emulate the response of a single neuron cell stimulated by periodic pulse inputs. Experimental results reveal that the output characteristics of the monolithic passively Q-switched laser can analogously manifest not only the firing patterns but also the frequency-locked plateaus of the single neuron cell. Moreover, the sine circle map is innovatively used to generate the output pulse sequences that can exactly correspond to experimental firing patterns. The present exploration indicates that a monolithic passively Q-switched solid-state laser is highly feasible to be developed as a compact artificial neuron cell.
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12
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Robertson J, Hejda M, Bueno J, Hurtado A. Ultrafast optical integration and pattern classification for neuromorphic photonics based on spiking VCSEL neurons. Sci Rep 2020; 10:6098. [PMID: 32269249 PMCID: PMC7142074 DOI: 10.1038/s41598-020-62945-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/19/2020] [Indexed: 11/24/2022] Open
Abstract
In today’s data-driven world, the ability to process large data volumes is crucial. Key tasks, such as pattern recognition and image classification, are well suited for artificial neural networks (ANNs) inspired by the brain. Neuromorphic computing approaches aimed towards physical realizations of ANNs have been traditionally supported by micro-electronic platforms, but recently, photonic techniques for neuronal emulation have emerged given their unique properties (e.g. ultrafast operation, large bandwidths, low cross-talk). Yet, hardware-friendly systems of photonic spiking neurons able to perform processing tasks at high speeds and with continuous operation remain elusive. This work provides a first experimental report of Vertical-Cavity Surface-Emitting Laser-based spiking neurons demonstrating different functional processing tasks, including coincidence detection and pattern recognition, at ultrafast rates. Furthermore, our approach relies on simple hardware implementations using off-the-shelf components. These results therefore hold exciting prospects for novel, compact and high-speed neuromorphic photonic platforms for future computing and Artificial Intelligence systems.
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Affiliation(s)
- Joshua Robertson
- Institute of Photonics, University of Strathclyde, 99 George St, Glasgow, G11RD, United Kingdom
| | - Matěj Hejda
- Institute of Photonics, University of Strathclyde, 99 George St, Glasgow, G11RD, United Kingdom
| | - Julián Bueno
- Institute of Photonics, University of Strathclyde, 99 George St, Glasgow, G11RD, United Kingdom
| | - Antonio Hurtado
- Institute of Photonics, University of Strathclyde, 99 George St, Glasgow, G11RD, United Kingdom.
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13
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Dillane M, Dubinkin I, Fedorov N, Erneux T, Goulding D, Kelleher B, Viktorov EA. Excitable interplay between lasing quantum dot states. Phys Rev E 2019; 100:012202. [PMID: 31499912 DOI: 10.1103/physreve.100.012202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Indexed: 06/10/2023]
Abstract
The optically injected semiconductor laser system has proven to be an excellent source of experimental nonlinear dynamics, particularly regarding the generation of excitable pulses. Typically for low-injection strengths, these pulses are the result of a small above-threshold perturbation of a stable steady state, the underlying physics is well described by the Adler phase equation, and each laser intensity pulse is accompanied by a 2π phase rotation. In this article, we show how, with a dual-state quantum dot laser, a variation of type I excitability is possible that cannot be described by the Adler model. The laser is operated so that emission is from the excited state only. The ground state can be activated and phase locked to the master laser via optical injection while the excited state is completely suppressed. Close to the phase-locking boundary, a region of ground-state emission dropouts correlated to excited-state pulses can be observed. We show that the phase of the ground state undergoes bounded rotations due to interactions with the excited state. We analyze the system both experimentally and numerically and find excellent agreement. Particular attention is devoted to the bifurcation conditions needed for an excitable pulse as well as its time evolution.
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Affiliation(s)
- M Dillane
- Department of Physics, University College Cork, Cork, Ireland
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
| | - I Dubinkin
- National Research University of Information Technologies, Mechanics and Optics, Saint Petersburg, Russia
| | - N Fedorov
- National Research University of Information Technologies, Mechanics and Optics, Saint Petersburg, Russia
| | - T Erneux
- Optique Nonlinéaire Théorique, Campus Plaine, CP 231, 1050 Bruxelles, Belgium
| | - D Goulding
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
- Centre for Advanced Photonics and Process Analysis, Cork Institute of Technology, Cork, Ireland
- Department of Mathematics, Cork Institute of Technology, Cork, Ireland
| | - B Kelleher
- Department of Physics, University College Cork, Cork, Ireland
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
| | - E A Viktorov
- National Research University of Information Technologies, Mechanics and Optics, Saint Petersburg, Russia
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14
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Dillane M, Tykalewicz B, Goulding D, Garbin B, Barland S, Kelleher B. Square wave excitability in quantum dot lasers under optical injection. OPTICS LETTERS 2019; 44:347-350. [PMID: 30644906 DOI: 10.1364/ol.44.000347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
Quantum dot lasers display many unique dynamic phenomena when optically injected. Bistability has been predicted in a region of high injection strength. Experimentally, we show that a square wave phenomenon, rather than a phase-locked bistability, is observed in this region. The squares can manifest as a periodic train but also as noise-driven Type II excitable events. We interpret the appearance of the square waves as a thermally induced breaking of the bistability. Indeed, we find experimentally that over the duration of a square, the relative detuning between the master and the slave evolves deterministically. A relatively simple, physically motivated, rate equation model is presented and displays excellent agreement with the experiment.
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15
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Garbin B, Javaloyes J, Barland S, Tissoni G. Interactions and collisions of topological solitons in a semiconductor laser with optical injection and feedback. CHAOS (WOODBURY, N.Y.) 2017; 27:114308. [PMID: 29195338 DOI: 10.1063/1.5006751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present experimental and numerical results about dynamical interactions of topological solitons in a semiconductor laser with coherent injection and feedback. We show different kind of interactions such as repulsion, annihilation, or formation of soliton bound states, depending on laser parameters. Collisions between single structures and bound states conserve momentum and charge.
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Affiliation(s)
- B Garbin
- The Dodd-Walls Centre for Photonic and Quantum Technologies, and Physics Department, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - J Javaloyes
- Departament de Física, Universitat de les Illes Balears, Cra. De Valldemossa, km 7.5, E-07122 Palma, Spain
| | - S Barland
- Université Côte d'Azur, CNRS, Institut de Physique de Nice, 1361 Route des Lucioles, 06560 Valbonne, France
| | - G Tissoni
- Université Côte d'Azur, CNRS, Institut de Physique de Nice, 1361 Route des Lucioles, 06560 Valbonne, France
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16
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Robertson J, Deng T, Javaloyes J, Hurtado A. Controlled inhibition of spiking dynamics in VCSELs for neuromorphic photonics: theory and experiments. OPTICS LETTERS 2017; 42:1560-1563. [PMID: 28409798 DOI: 10.1364/ol.42.001560] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report experimentally and theoretically on the controllable inhibition of spiking regimes in a 1300 nm wavelength vertical-cavity surface-emitting laser. Reproducible suppression of spiking dynamics is demonstrated at fast operation speeds (up to sub-ns rates) and with total control on the temporal duration of the spiking inhibition windows. This Letter opens new paths toward a photonic inhibitory neuronal model system for use in future neuromorphic photonic information processing modules and which are able to operate at speeds up to 8 orders of magnitude faster than biological neurons.
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17
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Garbin B, Dolcemascolo A, Prati F, Javaloyes J, Tissoni G, Barland S. Refractory period of an excitable semiconductor laser with optical injection. Phys Rev E 2017; 95:012214. [PMID: 28208426 DOI: 10.1103/physreve.95.012214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Indexed: 06/06/2023]
Abstract
Injection-locked semiconductor lasers can be brought to a neuronlike excitable regime when parameters are set close to the unlocking transition. Here we study experimentally the response of this system to repeated optical perturbations and observe the existence of a refractory period during which perturbations are not able to elicit an excitable response. The results are analyzed via simulations of a set of dynamical equations which reproduced adequately the experimental results.
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Affiliation(s)
- B Garbin
- Université Côte d'Azur-CNRS, Institut Non Linéaire de Nice, France
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, Auckland 1142, New Zealand
| | - A Dolcemascolo
- Université Côte d'Azur-CNRS, Institut Non Linéaire de Nice, France
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, via Valleggio 11, I-22100 Como, Italy
| | - F Prati
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, via Valleggio 11, I-22100 Como, Italy
- CNISM, Research Unit of Como, via Valleggio 11, I-22100 Como, Italy
| | - J Javaloyes
- Departament de Física, Universitat de les Illes Baleares, C/ Valldemossa km 7.5, 07122 Mallorca, Spain
| | - G Tissoni
- Université Côte d'Azur-CNRS, Institut Non Linéaire de Nice, France
| | - S Barland
- Université Côte d'Azur-CNRS, Institut Non Linéaire de Nice, France
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18
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Chen CY, Cheng CH, Lin FY. Single-sideband photonic microwave generation with an optically injected quantum-dot semiconductor laser. OPTICS EXPRESS 2016; 24:30537-30546. [PMID: 28059401 DOI: 10.1364/oe.24.030537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We studied single-sideband (SSB) photonic microwave generation with a high sideband rejection ratio (SRR) based on the period-one dynamical states of an optically injected quantum-dot (QD) semiconductor laser and demonstrated that the SSB signals have SRRs of approximately 15 dB higher than those generated with a conventional quantum-well semiconductor laser under conditions of optimal microwave power. The enhancement of SRR in the QD laser, which is important in mitigating the power penalty effect in applications such as radio-over-fiber optical communications, could be primarily attributed to a lower carrier decay rate in the dots, smaller linewidth enhancement factor, and reduced photon decay rate.
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19
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Wang C, Raghunathan R, Schires K, Chan SC, Lester LF, Grillot F. Optically injected InAs/GaAs quantum dot laser for tunable photonic microwave generation. OPTICS LETTERS 2016; 41:1153-1156. [PMID: 26977657 DOI: 10.1364/ol.41.001153] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present an experimental investigation on the period-one dynamics of an optically injected InAs/GaAs quantum dot laser as a photonic microwave source. It is shown that the microwave frequency of the quantum dot laser's period-one oscillation is continuously tunable through the adjustment of the frequency detuning. The microwave power is enhanced by increasing the injection strength providing that the operation is away from the Hopf bifurcation, whereas the second-harmonic distortion of the electrical signal is well reduced by increasing the detuning frequency. Both strong optical injection and high detuning frequency are favorable for obtaining a single sideband optical signal. In addition, particular period-one oscillation points of low sensitivity to the frequency detuning are found close to the Hopf bifurcation line.
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Otto C, Lingnau B, Schöll E, Lüdge K. Manipulating coherence resonance in a quantum dot semiconductor laser via electrical pumping. OPTICS EXPRESS 2014; 22:13288-13307. [PMID: 24921523 DOI: 10.1364/oe.22.013288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Excitability and coherence resonance are studied in a semiconductor quantum dot laser under short optical self-feedback. For low pump levels, these are observed close to a homoclinic bifurcation, which is in correspondence with earlier observations in quantum well lasers. However, for high pump levels, we find excitability close to a boundary crisis of a chaotic attractor. We demonstrate that in contrast to the homoclinic bifurcation the crisis and thus the excitable regime is highly sensitive to the pump current. The excitability threshold increases with the pump current, which permits to adjust the sensitivity of the excitable unit to noise as well as to shift the optimal noise strength, at which maximum coherence is observed. The shift adds up to more than one order of magnitude, which strongly facilitates experimental realizations.
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21
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Lingnau B, Chow WW, Lüdge K. Amplitude-phase coupling and chirp in quantum-dot lasers: influence of charge carrier scattering dynamics. OPTICS EXPRESS 2014; 22:4867-4879. [PMID: 24663826 DOI: 10.1364/oe.22.004867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate the dependence of the amplitude-phase coupling in quantum-dot (QD) lasers on the charge-carrier scattering timescales. The carrier scattering processes influence the relaxation oscillation parameters, as well as the frequency chirp, which are both important parameters when determining the modulation performance of the laser device and its reaction to optical perturbations. We find that the FM/AM response exhibits a strong dependence on the modulation frequency, which leads to a modified optical response of QD lasers when compared to conventional laser devices. Furthermore, the frequency response curve changes with the scattering time scales, which can allow for an optimization of the laser stability towards optical perturbations.
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Garbin B, Goulding D, Hegarty SP, Huyet G, Kelleher B, Barland S. Incoherent optical triggering of excitable pulses in an injection-locked semiconductor laser. OPTICS LETTERS 2014; 39:1254-1257. [PMID: 24690720 DOI: 10.1364/ol.39.001254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We experimentally study the response of an injection-locked quantum dot semiconductor laser in the excitable regime to perturbations from an external, incoherent laser. We show that excitable pulses may be triggered both for perturbation wavelengths close to that of the quantum dot device and wavelengths detuned even by a few tens of nanometers.
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Turconi M, Garbin B, Feyereisen M, Giudici M, Barland S. Control of excitable pulses in an injection-locked semiconductor laser. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:022923. [PMID: 24032917 DOI: 10.1103/physreve.88.022923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Indexed: 06/02/2023]
Abstract
In spite of numerous theoretical and experimental reports of excitability in lasers with injected signal based on the locking-unlocking transition, the response of the system to controlled external perturbations (which is at the basis of the definition of excitable systems) has not been experimentally studied yet. In the following, we analyze the response of an injection-locked semiconductor laser to different external perturbations. We demonstrate the existence of a perturbation threshold beyond which the response of the system is independent of the strength of the stimulation and, thus, demonstrate its excitable character. We show that optically perturbing such an excitable system via the control of the phase of the injection beam can be useful for optical pulse generation.
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Affiliation(s)
- M Turconi
- Université de Nice, CNRS UMR 7335, Institut Non Linéaire de Nice, 1361 route des lucioles 06560 Valbonne, France
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Lingnau B, Lüdge K, Chow WW, Schöll E. Failure of the α factor in describing dynamical instabilities and chaos in quantum-dot lasers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:065201. [PMID: 23367994 DOI: 10.1103/physreve.86.065201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Indexed: 06/01/2023]
Abstract
We show that the long-established concept of a linewidth-enhancement factor α to describe carrier-induced refractive index changes in semiconductor lasers breaks down in quantum-dot (QD) lasers when describing complex dynamic scenarios, found, for example, under high-excitation or optical injection. By comparing laser simulations using a constant α factor with results from a more complex nonequilibrium model that separately treats gain and refractive index dynamics, we examine the conditions under which an approximation of the amplitude-phase coupling by an α factor becomes invalid. The investigations show that while a quasiequilibrium approach for conventional quantum well lasers is valid over a reasonable parameter range, allowing one to introduce an α factor as a constant parameter, the concept is in general not applicable to predict QD laser dynamics due to the different time scales of the involved scattering processes.
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Affiliation(s)
- Benjamin Lingnau
- Institut für Theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
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Toomey JP, Nichkawde C, Kane DM, Schires K, Henning ID, Hurtado A, Adams MJ. Stability of the nonlinear dynamics of an optically injected VCSEL. OPTICS EXPRESS 2012; 20:10256-10270. [PMID: 22535116 DOI: 10.1364/oe.20.010256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Automated protocols have been developed to characterize time series data in terms of stability. These techniques are applied to the output power time series of an optically injected vertical cavity surface emitting laser (VCSEL) subject to varying injection strength and optical frequency detuning between master and slave lasers. Dynamic maps, generated from high resolution, computer controlled experiments, identify regions of dynamic instability in the parameter space.
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Affiliation(s)
- J P Toomey
- Department of Physics and Astronomy, Macquarie University, Sydney NSW 2109 Australia.
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Kelleher B, Goulding D, Pascual BB, Hegarty SP, Huyet G. Bounded phase phenomena in the optically injected laser. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:046212. [PMID: 22680561 DOI: 10.1103/physreve.85.046212] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/03/2012] [Indexed: 06/01/2023]
Abstract
Two routes to phase-locking in the optically injected laser system are investigated both involving limit cycles where the phase of the slave laser is unlocked but is nevertheless bounded. We use an experimental phase-resolving technique to unambiguously demonstrate the phenomenon via explicit phasors for the slave laser electric field. Theoretical considerations show that for locking mechanisms involving Hopf bifurcations, such limit cycles of bounded phase are generic. For weakly damped devices, such as quantum well lasers, this can involve an excited resonance at the relaxation oscillation frequency. For highly damped devices there is no such excitation but the bounded phase behavior must persist. Phasor portraits for other regimes are also obtained including a chaotic regime.
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Affiliation(s)
- B Kelleher
- Centre for Applied Photonics and Process Analysis, Cork Institute of Technology, Cork, Ireland
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Bonatto C, Kelleher B, Huyet G, Hegarty SP. Transition from unidirectional to delayed bidirectional coupling in optically coupled semiconductor lasers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:026205. [PMID: 22463298 DOI: 10.1103/physreve.85.026205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 11/15/2011] [Indexed: 05/31/2023]
Abstract
We investigate the transition from unidirectional to delayed bidirectional coupling of semiconductor lasers. By tuning the coupling strength in one direction we show how the locking region evolves as a function of the detuning and coupling strength. We consider two representative values of the relaxation oscillation damping: one where the relaxation oscillations are very underdamped and one where they are very overdamped. Qualitatively different dynamical scenarios are shown to emerge for each case. Several features of the delayed bidirectional system can be seen as remaining from the unidirectional system while others clearly arise due to the delayed coupling and are similar to effects seen in delayed feedback configurations.
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Affiliation(s)
- Cristian Bonatto
- Centre for Advanced Photonics and Process Analysis, Cork Institute of Technology, Bishopstown, Cork, Ireland
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Kelleher B, Goulding D, Huyet G, Viktorov EA, Erneux T, Hegarty SP. Dimensional signature on noise-induced excitable statistics in an optically injected semiconductor laser. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:026208. [PMID: 21929082 DOI: 10.1103/physreve.84.026208] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 06/14/2011] [Indexed: 05/31/2023]
Abstract
Noise-induced excitability is a prevalent feature in many nonlinear dynamical systems. The optically injected semiconductor laser is one of the simplest such systems and is readily amenable to both experimental and theoretical analysis. We show that the dimensionality of this system may be tuned experimentally and that this has a strong signature on the interspike statistics. The phase of the slave laser is resolved experimentally in the frame of the master laser, allowing an examination of the dynamics at extremely low injection strengths where intensity measurements alone cannot determine the dynamics fully. Generic phase equations are found for the different dimensional scenarios. When the dimensionality is greater than 1, we show that a precursor of a homoclinic bifurcation generates a noise-induced frequency and that the homoclinic bifurcation admits a bistability in the system.
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Affiliation(s)
- B Kelleher
- Centre for Applied Photonics and Process Analysis, Cork Institute of Technology, Cork, Ireland
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