Reservoir computing is a brain-inspired machine learning framework that employs signal-driven dynamical system, in particular harnessing common-signal-induced synchronization which widely observed nonlinear phenomenon. Basic understanding of working principle reservoir can be expected to shed light on how information stored and processed systems, potentially leading progress broad range sciences. As first step toward this goal, from the viewpoint physics theory, we study memory-nonlinearity...

We experimentally demonstrate random bit generation using multi-bit samples of bandwidth-enhanced chaos in semiconductor lasers. Chaotic fluctuation laser output is generated a with optical feedback and the chaotic injected into second to obtain intensity signal bandwidth enhanced up 16 GHz. The converted an 8-bit digital by sampling oscilloscope at 12.5 Giga per (GS/s). Random bits are bitwise exclusive-OR operation on corresponding its time-delayed signal. Statistical tests verify...

We propose a secure key distribution scheme based on correlated physical randomness in remote optical scramblers driven by common random light. The security of the depends practical difficulty completely observing phenomena. describe particular realization using synchronization semiconductor lasers injected with light randomly varying phase. experimentally demonstrate feasibility over distance 120 km.

Photonic reservoir computing is a new paradigm for performing high-speed prediction and classification tasks in an efficient manner. The major challenge the miniaturization of photonic need use integrated circuits. Herein, we experimentally demonstrate using circuit with semiconductor laser short external cavity. We propose method to increase number virtual nodes delayed feedback node intervals outputs from multiple delay times. perform time-series nonlinear channel equalization circuit....

We point out that for an oscillator subjected to noise the conventional phase equation is not a proper approximation even weak noise. present reduction method valid white Gaussian Numerical evidence demonstrates properly approximates dynamics of original oscillator. Moreover, we show that, in general, causes shift frequency and discuss its effects on entrainment.

It is shown that broadband chaos suitable for fast nondeterministic random-bit generation in small devices can be achieved a semiconductor laser with short external cavity. The design of the device based on theoretical model by amplification microscopic noise. Moreover, it demonstrated bit sequences passing common tests statistical randomness at rates up to 2.08 Gbits/s generated using on-chip lasers monolithically integrated cavity, amplifiers, and photodetector.

We propose a scheme for fast random number generation with bandwidth-enhanced chaotic semiconductor lasers. Chaotic laser intensity output and its time-delayed signal are sampled at 50 GigaSample per second converted into eight-bit values. The order of the samples is reversed, bitwise exclusive-or operation executed between bit-order-reversed original samples. With this method, it not necessary to eliminate any bits in obtain good-quality bit sequences. equivalent rate 8×50 Gb/s achieved an...

Random number generators are essential for applications in information security and numerical simulations. Most optical-chaos-based random produce bit sequences by offline post-processing with large optical components. We demonstrate a real-time hardware implementation of fast physical generator photonic integrated circuit field programmable gate array (FPGA) electronic board. generate 1-Tbit evaluate their statistical randomness using NIST Special Publication 800-22 TestU01. All the...

We investigate the characteristics of fast random bit generation using chaotic semiconductor lasers. The optical amplitudes two lasers with oscillations induced by feedback are each sampled at a fixed rate to extract binary sequences which then combined an exclusive-OR operation obtain single sequence. Bit generated 1 Giga per second verified pass statistical tests randomness. describe dependence randomness on laser parameters, in particular injection current, external cavity length and...

We report a novel chaos semiconductor laser chip in which distributed feedback (DFB) laser, two optical amplifiers (SOAs) and photodiode (PD) are monolithically integrated with passive ring waveguide. The ring-type structure the separate SOAs achieves stronger delayed compared to previous chips use linear waveguide facet-reflection. PD allows efficient detection of signal low loss. A rich variety dynamical behaviors signals can be selectively generated via injection currents SOAs. In...

It has been proposed that a secure key distribution scheme using correlated random bit sequences can be implemented common random-signal induced synchronization of semiconductor laser systems. In this it is necessary to use systems consisting multiple cascaded lasers against powerful eavesdropper. paper, we report the results an experimental study demonstrate possible in We also show generated synchronized used create information-theoretically between two legitimate users.

We generate random bit sequences from chaotic temporal waveforms by using photonic integrated circuits (PICs) with different external cavity lengths. investigate the condition for generating bits at sampling rates of single-bit generation method PICs. succeed in certified PIC 3, 4, 5, or 10-mm-long cavity, whereas cannot pass all statistical tests randomness when 1 2 mm-long is used.

We experimentally and numerically observe synchronization of two semiconductor lasers commonly driven by a chaotic laser subject to optical feedback. Under condition that the relaxation oscillation frequency is matched between response lasers, but mismatched drive we show it possible strongly correlated even when correlation low. also cross responses larger than over wide parameter region.

We experimentally achieve common-signal-induced synchronization in two photonic integrated circuits with short external cavities driven by a constant-amplitude random-phase light. The degree of can be controlled changing the optical feedback phase circuits. change leads to significant redistribution spectral energy and RF spectra, which is unique characteristic PICs cavity. matching spectra necessary between PICs, stable obtained over an hour presence feedback. succeed generating...

We analyze the time for growth of bit entropy when generating nondeterministic bits using a chaotic semiconductor laser model. The mechanism is modeled as 1-bit sampling intensity light output. Microscopic noise results in an ensemble trajectories whose increases with time. entropy, called memory time, depends on both strength and dynamics. It shown that average decreases logarithmically increase strength. argued ratio change logarithm can be used to estimate intrinsic dynamical rate this...

We theoretically show that completely stochastic fast physical random bit generation at a rate of more than one gigabit per second can be realized by using lasers with optical delayed feedback which creates high-dimensional chaos laser light outputs. The theory is based on the mixing property chaos, transduces microscopic quantum noise spontaneous emission in into transitions between discrete macroscopic states.

We investigate the dynamics of two semiconductor lasers with separate optical feedback when they are driven by a common signal injected from chaotic laser under condition non-identical drive and response. experimentally numerically show conditions which outputs can be highly correlated each other even though correlation is low. In particular, effects phase light on characteristics described. The maximum between response obtained matched lasers, while minimum observed difference in pi. On...

A high speed physical random bit generator is applied for the first time to a gigahertz clocked quantum key distribution system. Random phase-modulation in differential-phase-shift (DPS-QKD) system performed using 1-Gbps signal which generated by with chaotic semiconductor lasers. Stable operation demonstrated over one hour, and sifted keys are successfully at rate of 9.0 kbps error 3.2% after 25-km fiber transmission.

We experimentally show that a random optical pulse train can be generated by modulating bistable semiconductor ring laser. When the laser is switched from monostable to regime, it randomly selects one of two different stable unidirectional lasing modes, clockwise or counterclockwise modes. Non-deterministic sequences are driving switch parameter, injection current, with periodic signal. The origin nondeterministic randomness amplified spontaneous emission noise coupled counter-propagating...

We present a particular type of one-dimensional nonlinear lattice that supports smoothly propagating discrete breathers. The is constructed by imposing symmetry on its potential function. This crucially affects the profile and motion traveling breather. show any breather truly localized with no tail can propagate constant velocity. Theoretical analysis using an average Lagrangian explains this numerical observation.

We considered the general sampling form for estimate of Allan variance which is proposed measure frequency stability in time domain, and we defined a variable proportional to difference between average fractional fluctuations over interval τ derive autocorrelation coefficient process belongs. Calculations estimated proved that it may be convergent its true value with infinite sample number spectral densities noise. also applied results estimations measurements know influence considered. In...

We consider discrete breathers in one-dimensional diatomic Fermi–Pasta–Ulam type lattices. A breather the limit of zero mass ratio, i.e. anti-continuous limit, consists a finite number in-phase or anti-phase excited light particles, separated by particles at rest. The existence is proved for small ratio continuation from limit. prove that are all unstable near except those continued solutions consisting alternating particles.

We present an experimental method for directly observing the amplification of microscopic intrinsic noise in a high-dimensional chaotic laser system, with delayed feedback. In experiment, system is repeatedly switched from stable lasing state to state, and time evolution ensemble states starting same initial measured. It experimentally demonstrated that noises amplified by dynamics are transformed into macroscopic fluctuating signals, probability density output light intensity actually...