Artykuły w czasopismach: „Spiking laser”

1

Ballard, S. G., i D. C. Mauzerall. "SPIKING IN N2-LASER PUMPED DYE LASERS". Photochemistry and Photobiology 39, nr 4 (2.01.2008): 535–36. http://dx.doi.org/10.1111/j.1751-1097.1984.tb03889.x.

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Kovalev, Anton V., Evgeny A. Viktorov i Thomas Erneux. "Non-Spiking Laser Controlled by a Delayed Feedback". Mathematics 8, nr 11 (20.11.2020): 2069. http://dx.doi.org/10.3390/math8112069.

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In 1965, Statz et al. (J. Appl. Phys. 30, 1510 (1965)) investigated theoretically and experimentally the conditions under which spiking in the laser output can be completely suppressed by using a delayed optical feedback. In order to explore its effects, they formulate a delay differential equation model within the framework of laser rate equations. From their numerical simulations, they concluded that the feedback is effective in controlling the intensity laser pulses provided the delay is short enough. Ten years later, Krivoshchekov et al. (Sov. J. Quant. Electron. 5394 (1975)) reconsidered the Statz et al. delay differential equation and analyzed the limit of small delays. The stability conditions for arbitrary delays, however, were not determined. In this paper, we revisit Statz et al.’s delay differential equation model by using modern mathematical tools. We determine an asymptotic approximation of both the domains of stable steady states as well as a sub-domain of purely exponential transients.

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3

Dodd, J. W., i T. C. Marshall. "'Spiking' radiation in the Columbia free electron laser". IEEE Transactions on Plasma Science 18, nr 3 (czerwiec 1990): 447–50. http://dx.doi.org/10.1109/27.55913.

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Dodd, J. W., i T. C. Marshall. "“Spiking” radiation in the Columbia free electron laser". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 296, nr 1-3 (październik 1990): 4–8. http://dx.doi.org/10.1016/0168-9002(90)91180-j.

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Russo, Nélida A., i Ricardo Duchowicz. "High frequency fiber laser emission generated by pump spiking". Optics Communications 281, nr 13 (lipiec 2008): 3532–37. http://dx.doi.org/10.1016/j.optcom.2008.03.009.

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Robertson, Joshua, Ewan Wade, Yasmin Kopp, Julian Bueno i Antonio Hurtado. "Toward Neuromorphic Photonic Networks of Ultrafast Spiking Laser Neurons". IEEE Journal of Selected Topics in Quantum Electronics 26, nr 1 (styczeń 2020): 1–15. http://dx.doi.org/10.1109/jstqe.2019.2931215.

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Jeys, Thomas H. "Suppression of laser spiking by intracavity second harmonic generation". Applied Optics 30, nr 9 (20.03.1991): 1011. http://dx.doi.org/10.1364/ao.30.001011.

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Lenstra, Daan, Lukas Puts i Weiming Yao. "First-Passage-Time Analysis of the Pulse-Timing Statistics in a Two-Section Semiconductor Laser under Excitable and Noisy Conditions". Photonics 9, nr 11 (14.11.2022): 860. http://dx.doi.org/10.3390/photonics9110860.

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A two-section semiconductor laser can exhibit excitability for certain parameter settings. When used as a photonic spiking neuron, it is relevant to investigate its sensitivity to noise due to, e.g., spontaneous emission. Under excitable conditions, the system emits irregularly timed noise-triggered pulses. Their statistics is analyzed in terms of a first-passage time distribution for the fluctuating intensity to reach the threshold for excitable response. Two analytic approximations valid for short and long times, respectively, are derived which very well explain measured and simulated pulse-repetition time distributions. This provides physical insight into the noise-triggered spiking mechanism.

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Rostro-Gonzalez, Horacio, Jesus Pablo Lauterio-Cruz i Olivier Pottiez. "Modelling Neural Dynamics with Optics: A New Approach to Simulate Spiking Neurons through an Asynchronous Laser". Electronics 9, nr 11 (5.11.2020): 1853. http://dx.doi.org/10.3390/electronics9111853.

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In this paper, we propose a novel approach for implementing spiking neurons through an optical system. Spiking neurons are a new approach to emulate the neural processes that occur in the brain, known as the third generation of artificial neural networks. They have been successfully used to build a new technology called neuromorphic engineering, which looks for a better performance than traditional computing in tasks usually performed by AI-based systems. Our optical system consists of a low-cost laser source, based on a microcontroller and a continuous-wave laser diode; the microcontroller allows producing synchronous or asynchronous pulses with complex time profiles. Here, through said system we have successfully reproduced most of the neural dynamics observed in biological neurons. These dynamics have been reproduced using a very simple optical array with a great potential for the development of neuromorphic systems. The optical system has been experimentally validated.

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Sánchez-León, José Antonio. "Parabolic approximation in Kleinman's mechanical approach to laser spiking analysis". Journal of Applied Research and Technology 14, nr 3 (czerwiec 2016): 191–94. http://dx.doi.org/10.1016/j.jart.2016.05.005.

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Eichler, H. J., W. Filter i T. Weider. "Spiking of the CW mode-locked Nd:YAG laser: mathematical model". IEEE Journal of Quantum Electronics 24, nr 6 (czerwiec 1988): 1178–80. http://dx.doi.org/10.1109/3.241.

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A. Rahman Osman, Babiker, A. M. Awadelgied i Kais Al Naimee. "Optical Fiber Communications by means of Chaos Generation". FES Journal of Engineering Sciences 7, nr 1 (6.12.2014): 12. http://dx.doi.org/10.52981/fjes.v7i1.95.

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The Chaos in the single-mode semiconductor lasers is generated by means of an optoelectronic feedback. Chaotic been generation under selected experimental initial condition of semiconductor laser model with optoelectronics feedback under appropriate conditions. MATLAB packages using to simulate the model behavior of semiconductor laser diodes with optoelectronics feedback. The Chaos in the single-mode semiconductor lasers is generated by means of an optoelectronic feedback. And result generated due to the simulated models. The existence of slow chaotic spiking sequences in the dynamics of a semiconductor laser with an optoelectronic feedback demonstrated experimentally and theoretically.

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13

Ginoux, Jean-Marc, i Riccardo Meucci. "Slow Invariant Manifold of Laser with Feedback". Symmetry 13, nr 10 (8.10.2021): 1898. http://dx.doi.org/10.3390/sym13101898.

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Previous studies have demonstrated, experimentally and theoretically, the existence of slow–fast evolutions, i.e., slow chaotic spiking sequences in the dynamics of a semiconductor laser with AC-coupled optoelectronic feedback. In this work, the so-called Flow Curvature Method was used, which provides the slow invariant manifold analytical equation of such a laser model and also highlights its symmetries if any exist. This equation and its graphical representation in the phase space enable, on the one hand, discriminating the slow evolution of the trajectory curves from the fast one and, on the other hand, improving our understanding of this slow–fast regime.

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14

Kong, H. J., S. S. Lee, H. S. Kim, K. G. Han, N. S. Kim, K. Y. Um, J. R. Park i J. Y. Lee. "High-power Nd3+:glass laser system in KAIST (Sinmyung I)". Laser and Particle Beams 15, nr 2 (czerwiec 1997): 317–24. http://dx.doi.org/10.1017/s0263034600010612.

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A high-power Nd3+:glass laser system has been constructed and tested. This system consists of a master oscillator, a four-pass amplifier for preamplification, and five-stage amplifiers. The system has been demonstrated in excess of 80 J (2 TW) at 40-ps pulse duration. Final laser beam quality was quite good due to the compensation of the polarization distortion in the four-pass preamplifier, the minimization of the diffraction effect by the image relaying, and the elimination of high spatial frequency components by the spatial filtering. This enables us to obtain high laser output power without any severe spatial spiking effects. Gains and spatial profiles of output pulses were measured after each amplifier stage.

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15

Ni, Min, Xiaodong Lin, Xi Tang, Ziye Gao, Luyao Xiao, Jun Wang, Fan Ma, Qiulan Zheng i Tao Deng. "Image Transmission Based on Spiking Dynamics of Electrically Controlled VCSEL-SA Neuron". Photonics 8, nr 7 (25.06.2021): 238. http://dx.doi.org/10.3390/photonics8070238.

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Based on the spiking dynamics of the electrically controlled vertical-cavity surface-emitting laser with an embedded saturable absorber (VCSEL-SA), we propose an image transmission system using two unidirectionally coupled VCSEL-SAs and numerically investigate the binary-to-spike (BTS) conversation characteristics and the image transmission performance. The simulation results show that, through electrically injecting the binary data to VCSEL-SA, the BTS conversation can be realized and the conversion rate of BTS highly depends on the injection strength and bias current. Thus, the image transmission can be realized in the proposed system. Moreover, the parameter mismatches between these two VCSEL-SAs have some effects on the image transmission performance, but the encoded images are still successfully decoded even under certain parameter mismatches. In addition, spiking patterns can be also stored and transmitted in the cascaded system with optoelectronic feedback loop.

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16

OTSUKA, KENJU, i JYH-LONG CHERN. "VARIATION OF LYAPUNOV EXPONENTS ON A STRANGE ATTRACTOR FOR SPIKING LASER OSCILLATION". International Journal of Bifurcation and Chaos 04, nr 04 (sierpień 1994): 1053–60. http://dx.doi.org/10.1142/s0218127494000769.

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We analyze temporal variations in local Lyapunov exponents for chaotic spiking lasers in terms of standard deviation and Allan variance as a function of integral time τ. We show that standard deviations for local Lyapunov exponents become saturated in short τ regimes. The calculated Allan variance and power spectrum analysis suggest that the transition between stationary and nonstationary chaos takes place around the relaxation oscillation period of lasers, and that local Lyapunov exponents become nonstationary in time in the short τ regime.

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17

Caloi, R. M. "One-dimensional analysis of the spiking behavior in a free-electron laser". Physical Review A 46, nr 12 (1.12.1992): 7934–41. http://dx.doi.org/10.1103/physreva.46.7934.

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Liu, Yun, i Junji Ohtsubo. "Regenerative spiking oscillation in a semiconductor laser with a nonlinear delayed feedback". Physical Review A 47, nr 5 (1.05.1993): 4392–99. http://dx.doi.org/10.1103/physreva.47.4392.

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19

Kolmykov, R. P. "Determination of Boron, Lithium and Some Metals in Fly Ash by Laser Ablation ‒ Inductively Coupled Plasma ‒ Optical Emission Spectr ometry". Eurasian Chemico-Technological Journal 24, nr 2 (25.07.2022): 123. http://dx.doi.org/10.18321/ectj1324.

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To avoid potentially harmful wet sample preparation is offered to use laser ablation (LA) ‒ inductively coupled plasma ‒ optical emission spectrometry (ICP-OES) as a method for the elemental analysis of fly ash for boron, lithium, and some metals. For this purpose, synthetic samples were prepared by spiking with dissolved standards. As a result, great stability of calibration curves was achieved. It was found that a particle diameter less than 80 μm in fly ash is enough to have a satisfying homogeneity for successful calibration in the method of standard additions. The average recovery test for reference materials used in the study was 16–77% of the certified values for the elements observed. The low results might be the effect of spiking with calibration samples in the liquid state. This type of analysis requires further investigation. According to the results of elemental analysis, the content of boron and lithium was determined for ZUK-2 and SO-1, which was not previously noticed in other papers.

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20

Ricci, Leonardo, Alessio Perinelli, Michele Castelluzzo, Stefano Euzzor i Riccardo Meucci. "Experimental Evidence of Chaos Generated by a Minimal Universal Oscillator Model". International Journal of Bifurcation and Chaos 31, nr 12 (25.09.2021): 2150205. http://dx.doi.org/10.1142/s0218127421502059.

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Detection of chaos in experimental data is a crucial issue in nonlinear science. Historically, one of the first evidences of a chaotic behavior in experimental recordings came from laser physics. In a recent work, a Minimal Universal Model of chaos was developed by revisiting the model of laser with feedback, and a first electronic implementation was discussed. Here, we propose an upgraded electronic implementation of the Minimal Universal Model, which allows for a precise and reproducible analysis of the model’s parameters space. As a marker of a possible chaotic behavior the variability of the spiking activity that characterizes one of the system’s coordinates was used. Relying on a numerical characterization of the relationship between spiking activity and maximum Lyapunov exponent at different parameter combinations, several potentially chaotic settings were selected. The analysis via divergence exponent method of experimental time series acquired by using those settings confirmed a robust chaotic behavior and provided values of the maximum Lyapunov exponent that are in very good agreement with the theoretical predictions. The results of this work further uphold the reliability of the Minimal Universal Model. In addition, the upgraded electronic implementation provides an easily controllable setup that allows for further developments aiming at coupling multiple chaotic systems and investigating synchronization processes.

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21

DOEDEL, EUSEBIUS J., BART E. OLDEMAN i CARLOS L. PANDO L. "BIFURCATION STRUCTURES IN A MODEL OF A CO2 LASER WITH A FAST SATURABLE ABSORBER". International Journal of Bifurcation and Chaos 21, nr 01 (styczeń 2011): 305–22. http://dx.doi.org/10.1142/s021812741102843x.

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We consider a new mathematical model of a CO 2 laser with a fast saturable absorber. The system exhibits isolas of periodic solutions, along with their bifurcations, as the main parameter, the incoherent pump of the laser, is changed. The characteristic feature of these lasers is their spiking behavior; the spikes, passive Q-switching pulses, correspond to stable periodic solutions on the isolas. We also study the changes in the solution structure as a second parameter varies, namely, the one that is responsible for the extent of nonlinear losses. In particular, we determine what happens to the isolas and to the stability properties of the periodic solutions along them.

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Otsuka, Kenju, Hiroaki Utsu, Ryoji Kawai, Kazuyoshi Ohki, Yusuke Asakawa, Siao-Lung Hwong, Jing-Yuan Ko i Jyh-Long Chern. "Self-Induced Spiking Oscillations and Associated Instabilities in a Laser-Diode-Pumped Three-Mode Nd:YVO 4 Laser". Japanese Journal of Applied Physics 38, Part 2, No. 9A/B (15.09.1999): L1025—L1028. http://dx.doi.org/10.1143/jjap.38.l1025.

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Ding, Shengyuan, Shannon G. Matta i Fu-Ming Zhou. "Kv3-Like Potassium Channels Are Required for Sustained High-Frequency Firing in Basal Ganglia Output Neurons". Journal of Neurophysiology 105, nr 2 (luty 2011): 554–70. http://dx.doi.org/10.1152/jn.00707.2010.

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The GABA projection neurons in the substantial nigra pars reticulata (SNr) are key output neurons of the basal ganglia motor control circuit. These neurons fire sustained high-frequency, short-duration spikes that provide a tonic inhibition to their targets and are critical to movement control. We hypothesized that a robust voltage-activated K+ conductance that activates quickly and resists inactivation is essential to the remarkable fast-spiking capability in these neurons. Semi-quantitative RT-PCR (qRT-PCR) analysis on laser capture-microdissected nigral neurons indicated that mRNAs for Kv3.1 and Kv3.4, two key subunits for forming high activation threshold, fast-activating, slow-inactivating, 1 mM tetraethylammonium (TEA)-sensitive, fast delayed rectifier ( IDR-fast) type Kv channels, are more abundant in fast-spiking SNr GABA neurons than in slow-spiking nigral dopamine neurons. Nucleated patch clamp recordings showed that SNr GABA neurons have a strong Kv3-like IDR-fast current sensitive to 1 mM TEA that activates quickly at depolarized membrane potentials and is resistant to inactivation. IDR-fast is smaller in nigral dopamine neurons. Pharmacological blockade of IDR-fast by 1 mM TEA impaired the high-frequency firing capability in SNr GABA neurons. Taken together, these results indicate that Kv3-like channels mediating fast-activating, inactivation-resistant IDR-fast current are critical to the sustained high-frequency firing in SNr GABA projection neurons and hence movement control.

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24

Rasheed, Banaz O., Parekhan M. Aljaff, Kais A. Al Naimee, Mahdi H. Al Hasani i Riccardo Meucci. "High chaotic spiking rate in a closed loop semiconductor laser with optical feedback". Results in Physics 6 (2016): 401–6. http://dx.doi.org/10.1016/j.rinp.2016.07.006.

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Grigorieva, E. V., i S. A. Kaschenko. "Multistability of Spiking Regimes in a Model of a Laser with Delayed-Feedback". Radiophysics and Quantum Electronics 61, nr 8-9 (styczeń 2019): 614–22. http://dx.doi.org/10.1007/s11141-019-09921-w.

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Fu, Chentao, Shuiying Xiang, Yanan Han, Ziwei Song i Yue Hao. "Multilayer Photonic Spiking Neural Networks: Generalized Supervised Learning Algorithm and Network Optimization". Photonics 9, nr 4 (25.03.2022): 217. http://dx.doi.org/10.3390/photonics9040217.

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We propose a generalized supervised learning algorithm for multilayer photonic spiking neural networks (SNNs) by combining the spike-timing dependent plasticity (STDP) rule and the gradient descent mechanism. A vertical-cavity surface-emitting laser with an embedded saturable absorber (VCSEL-SA) is employed as a photonic leaky-integrate-and-fire (LIF) neuron. The temporal coding strategy is employed to transform information into the precise firing time. With the modified supervised learning algorithm, the trained multilayer photonic SNN successfully solves the XOR problem and performs well on the Iris and Wisconsin breast cancer datasets. This indicates that a generalized supervised learning algorithm is realized for multilayer photonic SNN. In addition, network optimization is performed by considering different network sizes.

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27

Chizhevsky, V. N., V. A. Kulchitsky i S. Ya Kilin. "Artificial spiking neuron based on a single-photon avalanche diode and a microcavity laser". Applied Physics Letters 119, nr 4 (26.07.2021): 041107. http://dx.doi.org/10.1063/5.0055392.

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Fetzer, Florian, Haoyue Hu, Peter Berger, Rudolf Weber, Peter Eberhard i Thomas Graf. "Fundamental investigations on the spiking mechanism by means of laser beam welding of ice". Journal of Laser Applications 30, nr 1 (luty 2018): 012009. http://dx.doi.org/10.2351/1.4986641.

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Richman, Bruce A., J. M. J. Madey i Eric Szarmes. "First observation of spiking behavior in the time domain in a free-electron laser". Physical Review Letters 63, nr 16 (16.10.1989): 1682–84. http://dx.doi.org/10.1103/physrevlett.63.1682.

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Lin, Li-Yi, T. C. Marshall i M. A. Cecere. "A solitary wave theory for spiking pulses emitted by a Raman free electron laser". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 341, nr 1-3 (marzec 1994): 265–68. http://dx.doi.org/10.1016/0168-9002(94)90361-1.

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31

Bian, Qi, Jun-Wei Zuo, Chuan Guo, Chang Xu, Yu Shen, Nan Zong, Yong Bo i in. "Spiking suppression of high power QCW pulse 1319 nm Nd:YAG laser with different intracavity doublers". Laser Physics 26, nr 9 (1.08.2016): 095005. http://dx.doi.org/10.1088/1054-660x/26/9/095005.

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Salleh, Ali Syariati Mohd, Haza Nuzly Abdul Hamed, Mohd Adham Isa i Habibollah Haron. "Hydrofluoroether Impurities—Chemical Detection Using a Deep Learning Laser Speckle Contrast Evolving Spiking Neural Network". IEEE Access 8 (2020): 216419–36. http://dx.doi.org/10.1109/access.2020.3040895.

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Komarov, A. K., A. K. Dmitriev, K. P. Komarov i F. Sanchez. "Passive mode-locking of a fiber laser operating in the regime of undumped regular spiking". Optics and Spectroscopy 121, nr 6 (grudzień 2016): 925–29. http://dx.doi.org/10.1134/s0030400x16120146.

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Grigorieva, E. V., i S. A. Kaschenko. "Chaotic spiking induced by variable delayed optoelectronic feedback in a model of class B laser". Optics Communications 407 (styczeń 2018): 9–16. http://dx.doi.org/10.1016/j.optcom.2017.08.069.

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35

Merlin, Jacques, C. Oliveira i Jia Cai Li. "Relation between Shape and 'Spiking' of a Laser Beam Profile and the Induced Superficial Temperature". Key Engineering Materials 46-47 (styczeń 1991): 175–88. http://dx.doi.org/10.4028/www.scientific.net/kem.46-47.175.

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Chen, Zih-Ling, Chao-Hsien Wu, Pouyan Shen i Shuei-Yuan Chen. "Pulse Laser Ablation in Water Fragmentation of Amorphous Silica in Water with Optional NaCl Spiking". Journal of Nanoscience and Nanotechnology 12, nr 9 (1.09.2012): 7066–74. http://dx.doi.org/10.1166/jnn.2012.6560.

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KARANTONIS, ANTONIS, MICHAEL PAGITSAS, YASUYUKI MIYAKITA i SEIICHIRO NAKABAYASHI. "SYNCHRONIZATION PHENOMENA IN NETWORKS OF COUPLED RELAXATION ELECTROCHEMICAL OSCILLATIONS". International Journal of Bifurcation and Chaos 16, nr 07 (lipiec 2006): 1951–60. http://dx.doi.org/10.1142/s0218127406015817.

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Networks of weakly coupled discrete electrochemical oscillators have the ability of synchronizing rapidly in-phase or out-of-phase, depending on the network geometry. It is shown that a network consisting of N relaxation electrochemical oscillators, coupled through inhibitory connections, can have (N - 1)! coexisting out-of-phase states, each state being a permutation of a periodic spiking sequence. The out-of-phase states can be modified by shots of laser pulse perturbations and the phase relation is stored as a coded spatiotemporal pattern. The ability of the network to function as a re-writable memory of (N - 1)! different spatiotemporal patterns is demonstrated experimentally for N = 4.

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Ahmadian, Yashar, Adam M. Packer, Rafael Yuste i Liam Paninski. "Designing optimal stimuli to control neuronal spike timing". Journal of Neurophysiology 106, nr 2 (sierpień 2011): 1038–53. http://dx.doi.org/10.1152/jn.00427.2010.

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Recent advances in experimental stimulation methods have raised the following important computational question: how can we choose a stimulus that will drive a neuron to output a target spike train with optimal precision, given physiological constraints? Here we adopt an approach based on models that describe how a stimulating agent (such as an injected electrical current or a laser light interacting with caged neurotransmitters or photosensitive ion channels) affects the spiking activity of neurons. Based on these models, we solve the reverse problem of finding the best time-dependent modulation of the input, subject to hardware limitations as well as physiologically inspired safety measures, that causes the neuron to emit a spike train that with highest probability will be close to a target spike train. We adopt fast convex constrained optimization methods to solve this problem. Our methods can potentially be implemented in real time and may also be generalized to the case of many cells, suitable for neural prosthesis applications. With the use of biologically sensible parameters and constraints, our method finds stimulation patterns that generate very precise spike trains in simulated experiments. We also tested the intracellular current injection method on pyramidal cells in mouse cortical slices, quantifying the dependence of spiking reliability and timing precision on constraints imposed on the applied currents.

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Šindelářová, Anna, Pavel Pořízka, Pavlína Modlitbová, Lucie Vrlíková, Kateřina Kiss, Milan Kaška, David Prochazka, Jakub Vrábel, Marcela Buchtová i Jozef Kaiser. "Methodology for the Implementation of Internal Standard to Laser-Induced Breakdown Spectroscopy Analysis of Soft Tissues". Sensors 21, nr 3 (29.01.2021): 900. http://dx.doi.org/10.3390/s21030900.

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The improving performance of the laser-induced breakdown spectroscopy (LIBS) triggered its utilization in the challenging topic of soft tissue analysis. Alterations of elemental content within soft tissues are commonly assessed and provide further insights in biological research. However, the laser ablation of soft tissues is a complex issue and demands a priori optimization, which is not straightforward in respect to a typical LIBS experiment. Here, we focus on implementing an internal standard into the LIBS elemental analysis of soft tissue samples. We achieve this by extending routine methodology for optimization of soft tissues analysis with a standard spiking method. This step enables a robust optimization procedure of LIBS experimental settings. Considering the implementation of LIBS analysis to the histological routine, we avoid further alterations of the tissue structure. Therefore, we propose a unique methodology of sample preparation, analysis, and subsequent data treatment, which enables the comparison of signal response from heterogenous matrix for different LIBS parameters. Additionally, a brief step-by-step process of optimization to achieve the highest signal-to-noise ratio (SNR) is described. The quality of laser–tissue interaction is investigated on the basis of the zinc signal response, while selected experimental parameters (e.g., defocus, gate delay, laser energy, and ambient atmosphere) are systematically modified.

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Al Husseini, H., SF Abdalah, KAM Al Naimee, R. Meucci i FT Arecchi. "Exploring phase control in a quantum dot light-emitting diode". Nanomaterials and Nanotechnology 8 (1.01.2018): 184798041878238. http://dx.doi.org/10.1177/1847980418782389.

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We report phase control in a periodically driven chaotic nanosystem consisting of a quantum dot light-emitting diode. Such a dynamical system is a class C laser, whence the charactering features are intrinsically chaotic. Phase control relies on the addition of small parametric harmonic perturbations with adjustable phase. Phase control is demonstrated by changing both frequency and strength of the controlling perturbations. Our results show that phase control has two crucial effects on a quantum dot light-emitting diode. First, it can enhance the spiking behavior in either regular or chaotic regimes; second, it is able to turn periodic behavior to chaotic behavior with a minimal perturbation when a resonance condition at half of the driving frequency is achieved.

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Vanzetta, Ivo, Corey Flynn, Anton I. Ivanov, Christophe Bernard i Christian G. Bénar. "Investigation of Linear Coupling Between Single-Event Blood Flow Responses and Interictal Discharges in a Model of Experimental Epilepsy". Journal of Neurophysiology 103, nr 6 (czerwiec 2010): 3139–52. http://dx.doi.org/10.1152/jn.01048.2009.

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A successful outcome of epilepsy neurosurgery relies on an accurate delineation of the epileptogenic region to be resected. Functional magnetic resonance imaging (fMRI) would allow doing this noninvasively at high spatial resolution. However, a clear, quantitative description of the relationship between hemodynamic changes and the underlying epileptiform neuronal activity is still missing, thereby preventing the systematic use of fMRI for routine epilepsy surgery planning. To this aim, we used a local epilepsy model to record simultaneously cerebral blood flow (CBF) with laser Doppler (LD) and local field potentials (LFP) in rat frontal cortex. CBF responses to individual interictal-like spikes were large and robust. Their amplitude correlated linearly with spike amplitude. Moreover, the CBF response added linearly in time over a large range of spiking rates. CBF responses could thus be predicted by a linear model of the kind currently used for the interpretation of fMRI data, but including also the spikes’ amplitudes as additional information. Predicted and measured CBF responses matched accurately. For high spiking frequencies (above ∼0.2 Hz), the responses saturated but could eventually recover, indicating the presence of multiple neurovascular coupling mechanisms, which might act at different spatiotemporal scales. Spatially, CBF responses peaked at the center of epileptic activity and displayed a spatial specificity at least as good as the millimeter. These results suggest that simultaneous electroencephalographic and blood flow-based fMRI recordings should be suitable for the noninvasive precise localization of hyperexcitable regions in epileptic patients candidate for neurosurgery.

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Bian, Qi, Yong Bo, Jun-wei Zuo, Chuan Guo, Chang Xu, Wei Tu, Yu Shen i in. "High-power QCW microsecond-pulse solid-state sodium beacon laser with spiking suppression and D_2b re-pumping". Optics Letters 41, nr 8 (6.04.2016): 1732. http://dx.doi.org/10.1364/ol.41.001732.

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Sánchez-Esteva, Sara, Maria Knadel, Rodrigo Labouriau, Gitte H. Rubæk i Goswin Heckrath. "Total Phosphorus Determination in Soils Using Laser-Induced Breakdown Spectroscopy: Evaluating Different Sources of Matrix Effects". Applied Spectroscopy 75, nr 1 (24.08.2020): 22–33. http://dx.doi.org/10.1177/0003702820949560.

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Laser-induced breakdown spectroscopy (LIBS) is a potential alternative to wet chemical methods for total soil phosphorus determination, but matrix effects related to physical and chemical sample properties need to be further understood. The aim of this study was to explore matrix effects linked to particle size distribution and chemical form of phosphorus on LIBS response and the ability of LIBS to predict total phosphorus in a range of different soil types. Univariate calibration curves were developed by spiking the soils with increasing doses of phosphorus, and limits of detection for LIBS determined phosphorous (P) (LIBS-P) were calculated. Different particle size distributions in otherwise identical soils were obtained by four milling treatments and effects of chemical form of phosphorus were examined by spiking soils with identical amounts of phosphorus in different chemical compounds. The LIBS-P response showed a high correlation (R2 > 0.99) with total phosphorus for all soils. Yet, the sensitivity of LIBS differed significantly among soils, as the slope of the calibration curves increased with increasing sand content, resulting in estimated limits of detection of 10 mg kg−1 for the sandiest and 122 mg · kg−1 for the most clayey soils. These limits indicate that quantitative evaluation of total phosphorus in sandy and loamy sandy soils by LIBS is feasible, since they are lower than typical total phosphorus concentrations in soil. A given milling treatment created different particle size distributions depending on soil type, and consequently different LIBS-P results. Thus, procedures that specify the required degree of homogenization of soil samples prior to analysis are needed. Sieving after milling could be an option, but that should be tested. The soils spiked with Fe(III) phosphate, potassium phosphate and phytic acid had similar LIBS-P, except for soils with hydroxyapatite, which resulted in markedly lower response. These results suggested that matrix effects related to the chemical nature of phosphorus would be minor for non-calcareous soils in humid regions, where apatites comprise only a small fraction of total phosphorus. Strategies to overcome matrix effects related to particle size and content of apatite-phosphorus by combining multivariate models and soil type groupings should be further investigated.

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Shirvani, H., i S. Jafari. "Quantum regime of a plasma-wave-pumped free-electron laser in the presence of an axial magnetic field". Journal of Synchrotron Radiation 25, nr 2 (14.02.2018): 316–22. http://dx.doi.org/10.1107/s1600577517018124.

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The quantum regime of a plasma-whistler-wave-pumped free-electron laser (FEL) in the presence of an axial-guide magnetic field is presented. By quantizing both the plasma whistler field and axial magnetic field, anN-particle three-dimensional Hamiltonian of quantum-FEL (QFEL) has been derived. Employing Heisenberg evolution equations and introducing a new collective operator which controls the vertical motion of electrons, a quantum dispersion relation of the plasma whistler wiggler has been obtained analytically. Numerical results indicate that, by increasing the intrinsic quantum momentum spread and/or increasing the axial magnetic field strength, the bunching and the radiation fields grow exponentially. In addition, a spiking behavior of the spectrum was observed with increasing cyclotron frequency which provides an enormous improvement in the coherence of QFEL radiation even in a limit close-to-classical regime, where an overlapping of these spikes is observed. Also, an upper limit of the intrinsic quantum momentum spread which depends on the value of the cyclotron frequency was found.

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Kovalev, Valeri I., i Robert G. Harrison. "The dynamics of a SBS fibre laser: the nature of periodic spiking at harmonics of the fundamental oscillation frequency". Optics Communications 204, nr 1-6 (kwiecień 2002): 349–54. http://dx.doi.org/10.1016/s0030-4018(02)01190-2.

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Eichler, H. J., I. G. Koltchanov i B. Liu. "Numerical study of the spiking instability caused by modulation frequency detuning in an actively mode-locked solid-state laser". Applied Physics B Laser and Optics 61, nr 1 (lipiec 1995): 81–88. http://dx.doi.org/10.1007/bf01090976.

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Tyszka, Krzysztof, Magdalena Furman, Rafał Mirek, Mateusz Król, Andrzej Opala, Bartłomiej Seredyński, Jan Suffczyński i in. "Leaky Integrate‐and‐Fire Mechanism in Exciton–Polariton Condensates for Photonic Spiking Neurons (Laser Photonics Rev. 17(1)/2023)". Laser & Photonics Reviews 17, nr 1 (styczeń 2023): 2370001. http://dx.doi.org/10.1002/lpor.202370001.

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Fang, Wei, Jian Lei, Pengda Zhang, Fei Qin, Meiling Jiang, Xufeng Zhu, Dejiao Hu, Yaoyu Cao i Xiangping Li. "Multilevel phase supercritical lens fabricated by synergistic optical lithography". Nanophotonics 9, nr 6 (18.04.2020): 1469–77. http://dx.doi.org/10.1515/nanoph-2020-0064.

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AbstractThe advent of planar metalenses, including the super-oscillatory lens (SOL) and the supercritical lens (SCL) with distinctive interference properties, has profoundly impacted on the long-lasting perception of the far-field optical diffraction limit. In spite of its conspicuous success in achieving marvelously small focal spots, the planar metalens still faces tough design and fabrication challenges to realize high focusing efficiency. In this work, we demonstrated a dual-mode laser fabrication technique based on two-photon polymerization for realizing the multilevel phase SCL with focusing efficiency spiking. Synergistically controlling two types of movement trajectory, which is implemented with the piezo stage and the scanning galvo mirror, enables the fabrication of complicated structures with sub-diffraction-limit feature size. By utilizing such advantage, SCLs with discretized multilevel phase configurations are explicitly patterned. The experimental characterization results have shown that a four-level phase SCL can focus light into a sub-diffraction-limit spot with the lateral size of 0.41 λ/NA (NA is the numerical aperture), while achieve the focal spot intensity and the energy concentration ratio in the focal region 7.2 times and 3 times that of the traditional binary amplitude-type SCL with the same optimization conditions, respectively. Our results may release the application obstacles for the sub-diffraction-limit planar metalens and enable major advances in the fields from label-free optical super-resolution imaging to high precision laser fabrication.

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Fernández, Beatriz, Fanny Claverie, Christophe Pécheyran i Olivier F. X. Donard. "Solid-spiking isotope dilution laser ablation ICP-MS for the direct and simultaneous determination of trace elements in soils and sediments". J. Anal. At. Spectrom. 23, nr 3 (2008): 367–77. http://dx.doi.org/10.1039/b711247e.

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Lam, Ying-Wan, i S. Murray Sherman. "Mapping by Laser Photostimulation of Connections Between the Thalamic Reticular and Ventral Posterior Lateral Nuclei in the Rat". Journal of Neurophysiology 94, nr 4 (październik 2005): 2472–83. http://dx.doi.org/10.1152/jn.00206.2005.

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We used laser scanning photostimulation through a focused UV laser of caged glutamate in an in vitro slice preparation through the rat’s somatosensory thalamus to study topography and connectivity between the thalamic reticular nucleus and ventral posterior lateral nucleus. This enabled us to focally stimulate the soma or dendrites of reticular neurons. We were thus able to confirm and extend previous observations based mainly on neuroanatomical pathway tracing techniques: the projections from the thalamic reticular nucleus to the ventral posterior lateral nucleus have precise topography. The reticular zone, which we refer to as a “footprint,” within which photostimulation evoked inhibitory postsynaptic currents (IPSCs) in relay cells, was relatively small and oval, with the long axis being parallel to the border between the thalamic reticular nucleus and ventral posterior lateral nucleus. These evoked IPSCs were large, and by using appropriate GABA antagonists, we were able to show both GABAA and GABAB components. This suggests that photostimulation strongly activated reticular neurons. Finally, we were able to activate a disynaptic relay cell-to-reticular-to- relay cell pathway by evoking IPSCs in relay cells from photostimulation of the region surrounding a recorded relay cell. This, too, suggests strong responses of relay cells, responses strong enough to evoke spiking in their postsynaptic reticular targets. The regions of photostimulation for these disynaptic responses were much larger than the above-mentioned reticular footprints, and this suggests that reticulothalamic axon arbors are less widespread than thalamoreticular arbors, that there is more convergence in thalamoreticular connections than in reticulothalamic connections, or both.

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