bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Aging and Visual Impairment on Dynamic Visual Acuity with Telescopic Spectacles During Vertical Motion
Authors: Demer Joseph L.
Published: February 2023

Telescopic spectacles are frequently prescribed for visually impaired patients, but visual rehabilitation with these costly devices is often unsuccessful. The retinal slip hypothesis suggests that one major cause of rehabilitation failure with telescopic spectacles is the result of patients’ inability to maintain adequate stability of magnified images on the retina during unintended head movements caused by ambulation, tremor, and postural instability. The visual-vestibulo-ocular reflex (VVOR), which normally produces eye movements to compensate for head movements, is overwhelmed when the visual effects of head movements are magnified by head-mounted telescopes, permitting instability of images on the retina.1 It has been demonstrated in normally sighted2 and low vision subjects3 wearing telescopic spectacles that horizontal head motion significantly decreases dynamic visual acuity (DVA), the acuity during relative motion. However, clinical studies suggest that spontaneous vertical head motion is an important determinant of successful rehabilitation with telescopic spectacles.3,4 Although vertical optotype and head motion with telescopic spectacles have been demonstrated to impair the DVA of young, normal subjects through the mechanism of retinal image instability,5 DVA for vertical relative motion has not been similarly studied in elderly or low vision subjects. Impaired VVOR performance in these subjects would be expected to compromise DVA.
Color Improves Low-Vision Object Recognition1
Authors: Legge Gordon E. , Wurm Lee H. , Isenberg Lisa M. , Luebker Andrew
Published: February 2023

Does color improve object recognition? Is the improvement greater for images with low spatial resolution where there is less shape information? Do people with low visual acuity benefit more from color than people with high acuity? We used a reaction-time (RT) procedure to study object recognition in normal and low vision. In this paper, we will focus on the low-vision findings.
Adult-Like Spatial Mechanisms in Human Infant Vision: VEP Adaptation Evidence for Multiple Interacting Channels in Infants Aged 3 to 12 Weeks
Authors: Suter Penelope S. , Roessler Jacqueline S. , Parker Kerrie L. , Suter Steve
Published: February 2023

Spatial vision in adults is thought to be mediated by multiple bandpass spatial frequency-tuned (SF-tuned) channels with inhibitory interactions. Existing preferential looking data imply that young infants lack these channels (Banks, Stephens, & Hartmann, 1985), instead, processing spatial information with multiple lowpass channels, or a single "channel". Further, questions have been raised as to whether inhibitory systems are in place to mediate spatial vision in the infant (e.g. Morrone & Burr, 1986). Previously, we have used a SF adaptation paradigm (Blakemore & Campbell, 1969) combined with visual evoked potentials (VEPs) to demonstrate the bandpass and inhibitory nature of SF channels in adults (Suter, Armstrong, Suter, & Powers, 1991). SF adaptation decreased VEP amplitude in a bandpass manner near the adapting SF, and increased VEP responding at SFs removed from the adapting SF. Increased contrast sensitivity thresholds, reduced cortical response, and reduction of VEP amplitude after adaptation may be due to neuronal fatigue or adjustment of a local contrast gain mechanism within the adapted channel (Ohzawa, Sclar, & Freeman 1985). Following adaptation, lower contrast sensitivity thresholds at SFs removed from the adapting SF have been explained by release of inhibition on neighboring channels when SF adaptation reduced responding of the adapted channel (De Valois, 1977). The research summarized here uses the VEP with the SF adaptation paradigm to demonstrate the existence of multiple, bandpass, co-inhibitory SF-tuned channels in 3, 6, and 12 week-old infants.
A New Reading-Acuity Chart for Normal and Low Vision
Authors: Mansfield J. Stephen , Ahn Sonia J. , Legge Gordon E. , Luebker Andrew
Published: February 2023

Functional measures of visual ability can be of great value in the treatment and care of patients with low vision, or in prescribing optical corrections for patients with normal vision. One such measure is reading ability. We have designed a new reading-acuity chart that is suited for testing observers with normal and low vision. Here we describe the new chart, and report preliminary data relating it to other measures of acuity.
Yearly Rates of Rod and Cone Functional Loss in Retinitis Pigmentosa and Cone-Rod Degeneration
Authors: Birch David G. , Anderson Jane L.
Published: February 2023

Although night-blindness is typically the earliest symptom, little is known about the progression of rod loss in retinitis pigmentosa. Since detectable rod ERGs are unusual in adults with retinitis pigmentosa, despite detectable cone ERGs, it seems likely that the rate of progression is faster for rods than for cones. The ability to assess therapeutic intervention in young patients with measures that show rapid progression should enhance attempts to alter the natural history of this potentially blinding disease. We are presently conducting a prospective natural history study utilizing psychophysical and electrophysiological measures of rod function in a large sample of patients with either retinitis pigmentosa or cone-rod degeneration. The present report contains a preliminary analysis of relative rates of rod and cone ERG loss in these diseases and a summary of yearly changes in parameters of full-field rod ERGs and rod visual fields.
High-Order Diffraction Due to Two-Beam Mixing in Photorefractive SBN:Ce
Authors: Zhang Hong-Jun , Tang Ze-Sun , Moore Thomas R. , Boyd Robert W.
Published: February 2023

Experimental observation of high-order diffraction in photorefractive SBN:Ce is reported. When two beams of nearly equal intensity are crossed in the crystal at a small angle (<1°) the transmitted beam contains many diffracted orders. Results are compared to thin grating scattering theory (i.e. Raman-Nath scattering).
Experimental Study Of Forward Phase Conjugate Wave In Four Wave Mixing In LiNbO3 :Fe Crystal
Authors: Xue-hua He , Hai Tang Sing , He-yi Zhang
Published: February 2023

Forward phase-conjugate wave in four wave mixing in photorefractive crystal LiNbO3: Fe was studied. The experimental setup used here is that both pump beams I1 and I2 are perpendicular to the surface of the crystal (i.e. I1 and I2 beams are perpendicular to c-axes of the crystal), the incident angle θ of signal beam I4 is varied from 10° ~ 40°. Both the forward and the backward phase conjugate image were observed at same time. The intensity of forward phase conjugate wave Ipf is comparable to the intensity of backward phase conjugate wave Ipb. For pump beam intensity I1 = I2 and θ = 30°, the intensity ratio of J 1 2 forward phase conjugate wave and backward phase conjugate wave Ipf/Ipb = 0.37 while the phase conjugate reflectivity Rph = 1.36.
Nonlinear Dynamical Effects in the Absorption Spectra of Weak Electromagnetic Field and in Four-Wave Mixing
Authors: Pestov E. G. , Oraevsky A. N.
Published: February 2023

The new nonlinear dynamical effects due to the influence of strong laser field (LF) on relaxation processes in two-level quantum systems are investigated. The dramatic change of the dependence of the probe field absorption spectral line shape and four-wave mixing amplification coefficient of weak field on LF intensity is discussed.
Photonic Neurodynamical Systems for Learning and Cognition
Authors: Farhat Nabil H.
Published: February 2023

We consider neural networks with feedback as nonlinear dynamical systems that can perform complex computations of the kind encountered in learning, optimization, and cognition at high speed especially when implemented in appropriate analog hardware. Progress in imbedding concepts of nonlinear dynamics in photonic hardware to produce neurocomputers with learning and cognitive ability, and the potential for using electron trapping materials that furnish unique photon storage function in such systems are discussed. Bifurcation in synchronously updated networks which support more than one type of attractor is described and proposed as mechanism for feature binding and cognition
Symbolic dynamics in the Belousov-Zhabotinskii reaction: from Rössler’s intuition to experimental evidence for Shil’nikov homoclinic chaos
Authors: Arneodo A. , Argoul F. , Richetti P.
Published: February 2023

The Belousov-Zhabotinskii reaction has revealed most of the well-known scenarios to chaos including period-doubling, intermittency, quasiperiodicity, frequency locking, fractal torus …. However, although the data have been shown to display unambiguous features of deterministic chaos, the understanding of the nature and the origin of the observed behavior has been incomplete. In 1976, Rössler suggested an intuitive interpretation to explain chemical chaos. His feeling was that nonperiodic wandering trajectories might arise in chemical systems from a pleated slow manifold (Fig. 1a), if the flow on the lower surface of the pleat had the property of returning trajectories to a small neighborhood of an unstable focus lying on the upper surface. In this communication, we intend to revisit the terminology introduced by Rössler of “spiral-type”, “screw-type” and “funnel-type” strange attractors in terms of chaotic orbits that occur in nearly homoclinic conditions. According to a theorem by Shil’nikov, there exist uncountably many nonperiodic trajectories in systems which display a homoclinic orbit biasymptotic to a saddle-focus O, providing the following condition is fulfilled: ρ/λ < 1, where the eigenvalue of O are (−λ, ρ ± iω). This subset of chaotic trajectories is actually in one to one correspondance with a shift automorphism with an infinite number of symbols. Since homoclinic orbits are structurally unstable objects which lie on codimension-one hypersurfaces in the constraint space, one can reasonably hope to cross these hypersurfaces when following a one-parameter path. The bifurcation structure encountered near homoclinicity involves infinite sequences of saddle-node and period-doubling bifurcations. The aim of this paper is to provide numerical and experimental evidences for Shil’nikov homoclinic chaos in nonequilibrium chemical systems.
Transient Chaotic Mode Competition in Nd3+-Doped Fiber Lasers
Authors: Le Flohic M. , Francois P. L. , Allain J. Y. , Sanchez F. , Stephen G.
Published: February 2023

The study of transient oscillations in Nd3+-doped fiber lasers shows that a chaotic spiking is obtained either for high pumping rates and/or at low temperatures. An improved laser model is proposed to understand this irregular behaviour. Using a multimode formalism, we show that a small homogeneous to inhomogeneous linewidths ratio leads to a strongly irregular spiking. The spectra of the laser emission reveal then a high number of active cavity modes.
Instabilities in Ultrashort Pulse Dye Lasers
Authors: MacFarlane Duncan L.
Published: February 2023

Pulse train instabilities have been reported in a large number of mode-locked lasers. We review the experimental work to date for ultrafast dye lasers and present a simple, analytic model that qualitatively describes certain phenomenology present in synchronously pumped mode-locked dye lasers.
Statistics for the Switch-On of a Laser with Injected Signal
Authors: Balle Salvador , San Miguel M. , De Pasquale F.
Published: February 2023

The passage time distribution associated with the switch-on of a laser with injected signal is calculated, yielding a scaling form with a single important parameter.
Nonlinear Dynamics Description of a Discretized Hybrid Optically Bistable Device
Authors: Mancini H. L. , Izaguirre E. , Alonso E. M. , D’Angelo R. J.
Published: February 2023

An analysis of the non-linear behavior of an hybrid bistable optical device (BOD) implemented with electrooptic modulators is presented in the limit when the input laser beam is pulsed and a one period delay is introduced in the feedback loop.

Experimental and numerical results are described showing period doubling route to chaos, type I intermittence and bi- and multi-stability, when the feedback loop parameters are changed.

Input optical pulse shape is preserved even when the system is operating in chaotic mode. Electronic delays only limit the maximum repetition rate.
Homoclinic Bifurcations in Thermo-optical Bistability with Localized Absorption
Authors: Roseli Joan I. , Pi Francese , Boixader Francese , Herrero Ramon , Farjas Jordi , Orriols Gaspar
Published: February 2023

We present numerical and experimental evidence of homoclinic bifurcations in opto-thermal bistable cavities with an absorbing mirror and a transparent bilayer spacer of opposite thermo-optic materials.
Super-Narrow Spectral Peaks: New Critical Phenomena in Optically Bistable Systems
Authors: Dykman M. I. , Mannella R. , McClintock P. V. E. , Stocks N. G.
Published: February 2023

Fluctuation-induced transitions between coexisting attractors in a periodically driven nonlinear system have been investigated theoretically and with an analogue electronic circuit model. Calculations and measurements of power spectral densities of fluctuations have revealed superimposed twin-peaked partial spectra and a super-narrow spectral peak whose intensity depends critically on the distance from the phase transition.
Singularity Spectra of the Free-Running Thermal Blooming Instability at Saturation
Authors: Viecelli J. A.
Published: February 2023

Computations of the f(α) -spectrum of the saturated optical intensity pattern produced by small scale thermal blooming show that the irradiance does not follow a log-normal distribution.
Instabilities and Chaos in the Free-Electron Laser
Authors: Rai Suranjana , Rai Jagdish
Published: February 2023

The dynamics of the free-electron laser are studied using the Heisenberg equations of motion. The laser emission is found to show regions of instabilities and chaos.
Applicability of Bifurcation to Chaos: Experimental Demonstration of Methods for Switching Among Multistable Modes in a Nonlinear Resonator
Authors: Aida Tahito , Davis Peter
Published: February 2023

We demonstrate two complementary control methods of nonlinear oscillation modes in a simple electro-optical nonlinear ring resonator for novel optical signal processing. Modes correspond to harmonics with a variety of discrete peak level modulation patterns. Modes with bit capacity up to about 265 bits have been observed to stably oscillate. The first method, seed signal injection method, selectively excites stable nonlinear modes using input digital codes. The second method, chaotic search method, stochastically switches to the modes using features. Modes with up to 21-bit capacity have been switched , demonstrating the feasibility of using this novel dynamical phenomena for optical signal processing.
Periodic and aperiodic pulsations in a sodium-filled resonator: experiment and model
Authors: Lange W. , Möller M. , Iwankiw K. , Oestreich M. , Nalik J.
Published: February 2023

Studies of instabilities in nonlinear optical resonators form a counterpart to studies on instabilities in lasers. The prototype of experimental systems is a sodium-filled resonator. In some experimental schemes very special conditions have been provided in order to allow a treatment of the sodium atoms as two-level systems; in these experiments the range of dynamic phenomena is very restricted [1]. In other experiments very interesting phenomena have been observed, but a detailed theoretical analysis was not feasible [2].
Dynamics of Lateral Modes in Semiconductor Laser Arrays
Authors: Wang Shawe-Shiuan , Winful Herbert G.
Published: February 2023

A continuum model is presented for the dynamics of semiconductor laser arrays. Simulations of both gain-guided and index-guided arrays yield stable or unstable outputs, depending on array parameters.
Transverse Instabilities in Laser Diode Arrays Under Free-Running and Injection-Locking Conditions
Authors: Jakobsen P. K. , Indik R. A. , Newell A. C. , Moloney J. V.
Published: February 2023

New classes of phase-locked solutions, their stability and instability in free-running or injection locking mode are discussed for multi-element laser diode arrays.
Cylindrical Symmetry Restoring by Noise in Spontaneous Pattern Formation in Lasers
Authors: Colet P. , Miguel M. San , Brambilla M. , Lugiato L. A.
Published: February 2023

The effect of noise in a pattern forming instability with a continously degenerate stationary solution is analyzed. Symmetry restoring and transient dynamics are discussed.
Chaotic Attractor in Dynamics of Thermal Lens Pattern
Authors: Meunier-Guttin S. , Gouesbet G. , Maheu B. , Caputo J. G.
Published: February 2023

Thermal lens oscillations have been studied and characterized by periodicity, quasiperiodicity, period doubling, frequency locking and chaos, with control parameters of temperature, laser power and geometry. An embedded chaotic attractor theory has been developed using fluid dynamics and nonlinear dynamics. The paper reports preliminary characterization of the experimental chaotic attractor and main features of the theoretical model.
Noise Power Spectrum Reduction Below Short-Noise Limit Due to the Radiation of a Laser with Intracavity Second-Harmonic Generation
Authors: Zhiliba A.
Published: February 2023

A source for generation of amplitude-squeezed states of the electromagnetic field in the process of the second harmonic generation (SHG) in the laser cavity is investigated. Amplitude squeezed states are resulted from the interaction of the laser mode whis a nonlinear cristal that is plased within the cavity of the laser.
Wave Competition, Squeezed States of Light, and Photon Superbunching in DFB System
Authors: Alodjants A. P. , Arakelian S. M. , Gevorkian L. P. , Chilingarian Yu. S.
Published: February 2023

A new method of formation of quantum states of the light in the linear system at dynamic diffraction is discussed for the first time. The approach gives a new opportunities for a verification of quantum properties of the light in experiment.
Explosive Absorption of IR Laser Radiation in Semiconductors
Authors: Protsenko I. E. , Oraevsky A. N. , Bundy D. K.
Published: February 2023

The necessary conditions for hysteresis in optical resonance absorbers with thermal equilibrium are found for arbitrary temperature dependencies on the absorption coefficient and the relaxation rate. The possibility of hysteresis for IR intravalence band semiconductor resonance is shown. The properties of nonlinear auto - waves in the systems with "explosive absorption" is discussed.
Coherent Effects in Ultrashort Pulse Generation by a Semiconductor Injection Laser
Authors: Belenov Edward M. , Vasil’ev Peter P.
Published: February 2023

Effects of coherent interaction of ultrashort pulses with an injection laser active medium are investigated both theoretically and experimentally. A breakup of the picosecond pulse envelop into subpulses and a train of coherent pulses with a repetition rate nearly 100 GHz are observed for the first time. The theoretical treatment of the laser dynamics is based on the Maxwell-Bloch equation taking into account the dependence of the intraband relaxation time on the electromagnetic field amplitude of the picosecond pulse, the inhomogenious line brodening mechanism and Raman scattering within the laser cavity.
Mechanisms of Amplification with Inversion
Authors: Kocharovskaya Olga
Published: February 2023

We analyze the physical origin of the gain in all schemes of inversionless amplification proposed to date and define two different mechanisms responsible for this process.
Polarization-Sensitive Population Trapping in an Optically Pumped Laser
Authors: Roldán E. , Vilaseca R. , de Valcárcel G. J. , Arjona M. , Pujol J. , Corbalán R.
Published: February 2023

As we have shown recently /1/, the efficiency of an optically pumped laser is strongly sensitive to the structure of the atomic (or molecular) levels involved in the amplifying process, in particular to M-degeneracy. Specifically, when the common level b shared by the pump and laser transitions in a typical three-level configuration (Fig.1) has two sublevels m=±1 and the pump and laser fields are both linearly polarized (such as in the case, for instance, of the ammonia farinfrared laser /2/), there is a large difference in the dynamics of the laser when the pump and laser field polarizations are parallel or orthogonal /1,2/.
Fast and slow self-phase modulation induced pulse shaping of subpicosecond pulses in semiconductor laser amplifiers
Authors: Dienes A. , Hong M. Y. , Heritage J. P.
Published: February 2023

Self- and cross-phase modulation (SPM, XPM) of picosecond pulses due to gain saturation in semiconductor laser amplifiers has been investigated, both theoretically and experimentally.1,2,3 Because of the large value of the so-called linewidth enhancement factor α, these effects can result in considerable nonlinear sweep and spectral broadening. The spectrally broadened pulses can be partially compressed1,2 by providing dispersion externally. It has also been shown3 that the quadratic shape of the gain spectrum can result in considerable positive second-order phase dispersion. For pulse durations of about 1 ps or shorter (and input energies in the 0.1-1 pj range) the fast n2 must also be considered. The gain saturation induced “slow” self phase modulation (SSPM) is an integrating, energy dependent effect. On the other hand, the fast n2 responds to the instantaneous intensity of the pulse, resulting in “fast” self phase modulation (FSPM). The interplay of saturation, two kinds of SPM and dispersion will result in complicated pulse shaping. In this paper, we investigate the evolution of subpicosecond pulses in semiconductor amplifiers using a differential equation similar to one used for studying saturated dye laser amplifiers.4 Under certain conditions, soliton-like compression effects are predicted.
Time inverted type-I intermittency of a single mode laser
Authors: Tang D. Y. , Weiss C. O.
Published: February 2023

Among the three well-known routes to chaos in nonlinear dissipative dynamical systems, onset of chaos via intermittency has been extensively studied. Different types of intermittency have been revealed experimentally /1-3/. Recently intermittent transition to chaos through type-II and type-III intermittency have also been observed in optical systems /4,5/. To our knowledge, however, type-I intermittency has not been observed in optical systems so far.
Dynamics of Monovelocity Atomic Beam Maser
Authors: Oraevsky A.N. , Sarkissian T.V. , Jones D. J. , Bandy D.K.
Published: February 2023

The dynamics of a beam maser, the first device in quantum electronics, was the subject of attention more than thirty years ago[1-4]. However, the interest in a beam masers has increased recently due to their applications in the study of fine quantum effects of atom interaction with the cavity field[5-6]. One of the most important feature of the presently used maser is a monovelocity atomic beam. A theory of a monovelocity beam maser was developed by Filipowicz et al.[7] and Guzman et al[8].
Interferometric Configurations For Laser Mode-Locking Using a Nonlinear Active Medium
Authors: Cormier Jean-François , Piché Michel
Published: February 2023

The generation of femtosecond optical pulses using the feedback from an external nonlinear cavity is now a well established technique. The principle consists of interfering a reference pulse with a chirped version of itself, where the chirping is due to self-phase modulation (SPM) in a Kerr-like material. By adjusting the relative phase between the pulses, it is possible to achieve pulse shortening at each round-trip and positive differential gain for the short pulse.
Pulse Train Instabilities and Pulse Structure Evolution in Nd:Yag Laser with Active Mode-Locking
Authors: Mel’nikov L.A. , Tatarkov G.N.
Published: February 2023

The low-frequency instability (LFI) of the pulse-train envelope in actively mode locked (AML) laser strongly limits the range of parameters in which the pulse energy and pulse duration may be effectively controlled. It was shown experimentally [1-4] that the detuning of loss modulation frequency about few kHz in Nd:YAG lasers leads to appearance of LFI. Although numerous attempts were made for the theoretical investigation of AML destroying the origins of instabilities remain not clear yet. It was shown also [4,5] that for adequate determination of the width of stable locking region the single-pulse ( for example gaussian pulse [6]) approximation is not valid and it’s necessary to include the possibilities of the additive pulse formation within round-trip temporal interval.
The Transitions to Chaos in the Laser with a Saturable Absorber
Authors: Talarkova S. A. , Tuchin V. V.
Published: February 2023

The CO2 laser with a saturable absorber (LSA) generates the continuous pulse sequence which is well known as a passive Q-switching (PQS). Single pulse consists a narrow peak with the long oscillating tail. The pulse length and its shape essentially depends from a choice of the absorbing media and its parameters The occurrence of chaos in this system has been demonstrated by the experimental and theoretical investigations. Chaos arises according one of the famous scenarios. The theoretical model adequately describing the dynamical characteristics consists of the five differential equations for the field, polarizations and population differences of the amplifying and absorbing cells [1]. In this model LSA has three fixed points corresponding to the trivial laser-off solution and stationary solution. As the recent investigations showed [2,3] depending on the nature of the instability of these points different temporal regimes can arises.
Generalized finite-dimensional model of an inhomogeneously broadened single mode laser
Authors: Melnikov L. A. , Toronov V.Yu.
Published: February 2023

Numerical simulation of the dynamics of inhomogeneously broadened lasers requires an enormous computer resources because of their semiclassical models contain infinite degrees of freedom. Therefore the construction of a finite-dimensional models for such lasers is the present-day problem.
Mode-Locking Dynamics of Synchronously Pumped Color-Center Lasers
Authors: Forysiak W. , Moloney J.V.
Published: February 2023

Numerical simulations of the mode-locking dynamics of synchronously pumped KCl:Tl°(1) and

L
i
F
:

F
2
+

colour-centre lasers [1,2] in Fabry-Perot and ring geometries are presented. The response of each laser to variation of cavity mismatch is discussed and in particular, their pulse-shaping properties and the conditions required for pulse optimisation and stabilisation. Each of the cavity tuning curves consists of a narrow region of quasi-stationary pulsation, bounded by regions in which the presence of spontaneous emission noise generates episodic phase-wave perturbations, leading to a fundamental pulse jitter [3]. The resulting pulse characteristics are independent of whether the lasers are configured in Fabry-Perot or unidirectional ring geometries, but the detailed pulse shapes and the stability boundaries of the two lasing species differ slightly. Thus, whereas it is possible to minimise the phase-wave fluctuations at the peak of the Tl°(1) tuning curve to generate optimised, quasi-stationary pulses, in

F
2
+

a slight detuning from optimum is required, albeit by only approximately 15%. The equivalent bidirectional ring lasers exhibit regions of quasi-stationary, spontaneously unidirectional lasing, bounded by regions of competitive, bidirectional switching. The physical mechanism governing bidirectional switching is the same as that driving pulse jitter in the Fabry-Perot and unidirectional ring configurations, namely, the passage of spontaneous noise induced phase-waves [4]. Consequently, there is a simple correspondence between the two operating regimes of the bidirectional ring lasers and the quasi-stationary and fluctuating regimes of the other laser geometries.
Dynamics of cw Solid-State Laser with Saturable Absorber
Authors: Viktorov E.A. , Mak A.A. , Orlov O.A. , Ustyugov V.I.
Published: February 2023

The investigations of cw operation of solid-state laser with narrow bandwidth intracavity saturable absorber are interesting from a view point of nonlinear dynamics problems as well as for spectroscopic applications. A number of publications was devoted to the matter, but as for the experimental works, they were carried out only with gas lasers1,2 (we do not mention here great number of experiments with broad-band saturable absorbers).
Density Of Probability Distribution For Quantum Electromagnetic Field
Authors: Protsenko I.E.
Published: February 2023

Based on the first principles of quantum mechanic the density of probability distribution function W(x,p) is created for quantum electromagnetic field (QEF) - Figs. 1, 2. Unlike a well-known distributions of density of quasi-probability (as Wigner function et.c.) W(x,p) can be measured directly in 8-port homodyne experiment or in the experiment we propose. Using W(x,p) one can calculate the probability to have the field quadratures x and p in a chosen area of a phase space, find the minimum in amplitude or phase fluctuations of QEF. W(x,p) predicts the lemniscate-of-ellipse shape of the dispersion of squeezed QEF (Loudon, 1989; Kimble, 1986). Using a methods of quantum optic in experimental study of W(x,p) one can reconstruct the wave function of QEF and, in principle, the wave function of an emitting substance.
High-Dimensional Dynamics in Semiconductor Lasers
Authors: Fischer I. , Sacher J. , Elsäßer W. , Göbel E.O.
Published: February 2023

We investigate a dynamical system consisting of a one-facet-AR-coated laserdiode coupled to a T-shaped resonator.
Transient multimode statistics in nearly single—mode semiconductor lasers
Authors: Valle A. , Colet P. , Pesquera L. , Miguel M. San
Published: February 2023

Mode partition noise in optical fiber communication systems is still causing an error rate floor even with distributed-feedback (DFB) lasers sources [1,2] having a side-mode suppression ratio larger than 30 dB in stationary conditions. This phenomenon is caused by the laser turning on initially in a side mode having a different wavelength from the principal mode.
Nonlinear Dynamics of Extremely Short Electromagnetic Pulses in Passive and Active Media
Authors: Belenov E. M. , Nazarkin A. V.
Published: February 2023

Summary not available.
Polarization Bistability in Laser Diodes
Authors: Kawaguchi Hitoshi , Irie Tomoyoshi , Tan-no Naohiro
Published: February 2023

Bistable laser diodes (BLDs) are expected to be key components in future optical communication and switching systems, because of the advantage in providing inherent optical gain. Several kinds of BLDs have been developed thus far [1]. One of the most important remaining problems with such devices is their limited switching speed and repetition rates.
Transition in the coherence collapse of semiconductor lasers with external optical feedback: Two types of low frequency fluctuations
Authors: Sacher J. , Elsäßer W. , Göbel E.O.
Published: February 2023

Semiconductor laser diodes with external optical feedback (EOFSL) have found considerable interest within the last 10 years /1–6/. This is due to the practical importance of this system as well as the EOFSL can serve as a model system for the investigation of the dynamics of nonlinear systems with countable infinite dimensions. EOFSL exhibit drastic changes in the output behavior for specific values of the operation parameters, especially a coherence collapse of the laser output can be found /1/. Experiments and numerical simulations have explained these changes by a quasiperiodic route to chaos for the variation of the feedback level /2/ as well as by an intermittency route /3/ for the variation of the injection current.
Injection Locking of Vertical-Cavity Surface-Emitting Laser
Authors: Boggavarapu D. , Grantham J. W. , Hu Y. Z. , Gibbs H. M. , Khitrova G. , Koch S. , Sargent M. , Chow Weng W.
Published: February 2023

Injection locking phenomena in oscillators has been studied in many laser systems (see for example [1]) including semiconductor lasers [2]. The vertical-cavity surface-emitting laser (VCSEL) provides an interesting system to investigate injection locking behavior due to its short cavity length (~ 1 μm), which also results in a single lasing cavity longitudinal mode. We have studied locking dynamics in a highly noisy laser system in the strong external injection regime and observed relaxation oscillation frequency generation of up to 50 GHz.
Dynamics of a Twin Stripe Semiconductor Laser Array: Coupled Mode Theory vs The PDE Model
Authors: Rahman Lutfur , Winful Herbert G.
Published: February 2023

In this paper we present numerical solutions for a partial differential equation (PDE) model1 for the dynamics of a twin stripe semiconductor laser array. The model includes carrier diffusion and the effects of propagation. A coupled-mode ordinary differential equation (ODE) model2 is then derived from this PDE model. The two models are compared in predicting the dynamical behavior of the laser array. We obtain good qualitative and quantitative agreement between the two models. The results obtained can be readily extended to larger arrays.
Space-Time Dynamics of Semiconductor Lasers: Many-Body Theory and Phenomenological Models
Authors: Moloney J.V. , Ru P. , Indik R. , Koch S.W. , Wright E.
Published: February 2023

The space-time dynamical behaviour of multi-stripe index/gain guided semiconductor laser arrays and broad area lasers is studied using the semiconductor Maxwell-Bloch laser model including transverse diffraction of the counterpropagating optical fields and transverse diffusion of the excited carriers. Our results confirm that evanescently coupled multi-stripe lasers are a fascinating manifestation of spatio-temporal complexity in spatially extended nonlinear systems. Stabilization of the laser output can be achieved by injection-locking the array with a weak external injected signal. The broad area laser shows random intensity filamentation in free-running mode and can be stablized to produce high power output by using the unstable resonator configuration for transverse mode discrimination.
Network of Chaotic Elements
Authors: Kaneko Kunihiko
Published: February 2023

Network of globally coupled chaotic elements is important not only as a model for nonlinear systems with many degrees of freedom, but also from the viewpoint of biological information processing and possible engineering applications.
Control of Chaos in a Multimode Solid State Laser: Numerical Results
Authors: Colet Pere , Roy Rajarshi
Published: February 2023

The stabilization of unstable periodic orbits embedded in a chaotic attractor has received great attention recently. In the original algorithm proposed by Ott, Grebogi and Yorke [1] (OGY) control is achieved by means of small perturbations of a system parameter which are proportional to the deviation of the system from the unstable fixed point. A related but different technique to control a chaotic system is the occasional proportional feedback technique (OPF) [2]. Experiments demonstrating the control of chaos in a multimode solid state laser using this technique have been reported recently [3]. Here we study the theoretical model for such laser and compare with the experimental results.
Hamiltonian Dynamics of Parametric Nonlinear Wave Mixing
Authors: Trillo S. , Wabnitz S.
Published: February 2023

Exact solutions in terms of elliptic integrals to the problem of mixing between a wave and its second-harmonic in a medium with quadratic and/or cubic nonlinearity have been reported in the nonlinear optics literature since the early sixties [1-4]. These solutions involve rather cumbersome expressions which do not lead to an immediate insight into the physics of the conversion process.
Applications of Fiber Optic Interferometry in Nonlinear Dynamics
Authors: Vohra S.T. , Bucholtz F.
Published: February 2023

The ultimate performance of a fiber optic (FO) interferometer depends on its ability to resolve small differential optical phase shifts. Due to advances in FO technology it has become possible to fabricate interferometers with optical phase resolution of < 1 μrad/√Hz (f >100 Hz) [1]. Such FO interferometers have been successfully utilized in making extremely high resolution acoustic and electromagnetic field sensors [1]. Since the optical phase shift in the fiber is directly proportional to the induced strain in the material bonded to the optical fiber the FO interferometer is also well suited for studying the dynamic strain response of magnetostrictive, piezoelectric and electrostrictive materials [2].
Switch-on Time Statistics of a Single-Mode Semiconductor Laser with an Injected Signal
Authors: Torrent M.C. , Sancho J.M. , Miguel M. San , Balle S.
Published: February 2023

Previous studies[1-3] of switch-on times in the presence of an injected signal considered class A-lasers. Here we consider the suitability of semiconductor lasers for detection of weak signals. The main difference with former studies is that now the carrier number cannot be adiabatically eliminated, so that the laser frequency is not constant during the laser switch-on.
Light Dynamics of Bistable Element Chain
Authors: Logvin Yu. A. , Samson A.M.
Published: February 2023

The light dynamics of bistable element chain is theoretically considered within the scope of the plane wave approximation. It is supposed that bistable elements are arranged In line and coupled by the light beams (see fig.). As a model is chosen the bistable thin film of two-level atoms [1,2] subjecting to the relation (1) where e
i
and e
t
- the amplitudes of incident and transmitted field, C - the cooperative parameter of the film [3].
The Effects of Nonlinear Gain on the Stability of Two-Element Evanescently Coupled Laser Arrays
Authors: Nichols D. T. , Winful H. G.
Published: February 2023

Arrays of semiconductor lasers have become widely used as compact sources of intense radiation, generating watts of power in diffraction limited beams. [1] Their high power makes them attractive as potential sources for optical fibers. However, their dynamical behavior is not well understood. Ordinarily, the problem is handled by solving a set of coupled nonlinear differential equations which are descriptive of the coupling of the carrier and photon populations in a single device as well as the the coupling between the individual devices. When writing these equations, one generally assumes that the optical gain is independent of the intensity. However, from a physical perspective, it is reasonable to postulate that the gain will begin to decrease significantly for sufficiently large photon populations. Several models have been utilized in order to describe the phenomenon of gain saturation [2]. One formalism assumes that the gain may be described by g = g
L
(1 − ϵX2), where X is a normalized electric field and X2 is proportional to the photon density in the laser cavity. This formalism is, however, only valid for low power levels. A second phenomenological form uses g = g
L
(1 + ϵX2)−1. This model has its origins in the two-level model and, since a semiconductor laser connot be described completely by the two-level model, a third model, which is taken from a non-perturbative density matrix calculation, has been formulated in which

g
=

g
L

1
+
ε

X
2

−

1
2

. It is clear that the presence of nonlinear gain will be a stabilizing influence on arrays of lasers, but to what degree is unclear. In the present study, we determine stability criteria for a two-element evanescently coupled laser array using each of the three models mentioned above in an effort to predict the effect of nonlinear gain on these arrays.
Dynamic Optical Bistability in A Semiconductor Doped Glass Etalon
Authors: Li Chunfei , Song Yinglin , Zha Zizhong , Zhang Lei
Published: February 2023

In the past decade, experimental results of transient optical bistabilities in etalons of CdSxSe1-x doped glasses have been presented by many authors[1-3]. Switching speed of ns to ps orders has been obtained. However, there still do not exist a dynamics theory of this transient optical bistability. This paper emphasizes the dependence of the implementation of transient optical bistabilities on the incident pulse width, the media response time, the FP cavity establishing time, and also, the influence of the incident pulse width on the switching speed.
Multiparametric Criticality in a Laser System
Authors: Kuznetsov A.P. , Kuznetsov S.P. , Sataev I.R.
Published: February 2023

Beside chaotic and regular dynamics, the special kind of behaviour occurs in nonlinear systems. This is the critical state arising usually just at the onset of chaos. Its distinctive peculiarity is a presence of the wide band of characteristic temporal scales up to infinitely large ones in the generating signal.
Bifurcation and Chaos in the Presence of External Noise
Authors: Anishchenko V.S. , Neiman A. B.
Published: February 2023

The present work investigates the influence of external non-white noise on some bifurcations of states of equilibrium, period-doubling bifurcation and on the dynamical chaos regimes. Lorenz system [1] and Anishchenko–Astakhov oscillator [2] are used as models. The peculiarities of the present investigation are in combination of numerical simulations with physical experiment and also in the use of cumulant analysis.
Interaction of Spatiotemporal Wave Structures in Nonlinear Optical Resonators: New Routes in Optical Turbulence
Authors: Vorontsov M. A.
Published: February 2023

Summary not available at press time.
History of Optical Solitons
Authors: Hasegawa Akira
Published: February 2023

Summary not available.
Transmision of solitons generated by modulation of laser diodes with mydsystem phase conjugation
Authors: Mirasso Claudio R. , Pesquera Luis
Published: February 2023

It has been recently pointed out that pseudorandom sequences of solitons can be generated and transmitted at GHz rates by direct modulation of laser diodes (LD) when biasing slightly below threshold1. Using this bias current the response of the gain-switched laser to a bit ”1” is independent of the previous input bits2. Then the large pulse fluctuations due to pattern effects, produced by the random sequences of input bits, are avoided and soliton generation under pseudorandom word modulation conditions is possible. Using solitons generated by gain-switched LD at GHz rates a large time jitter has been observed after transmission over transoceanic distances3. We have shown that this is due to the pulse-to-pulse frequency jitter originated in the LD4. Other important effects at high bit rates are soliton interation and Gordon-Hauss jitter. It has been demonstrated that midsystem optical phase conjugation (OPC) can reduce these effects in periodically amplified soliton transmission systems5.
Modulational instability induced by quadratic nonlinearities
Authors: Ferro Paolo , Trillo Stefano , Buryak Alexander V. , Kivshar Yuri S.
Published: February 2023

The large nonlinear phase shifts obtained with cascaded nonlinearities [1] has attracted renewed interest in the parametric interaction of a fundamental frequency (FF) beam with its doubled frequency (DF) [2]. A pure phase-shift, not accompanied by any energy transfer, may be achieved at any phase mismatch, by exploiting the nonlinear eigenmodes of the interaction [3,4]. These are symbiotic pair of phase-locked FF and DF cw’s which propagate without mutually exchanging energy but independently experiencing a nonlinear phase-shifts. Here we predict that when dispersion is taken into account this cw eigenmodes are subject to modulational instability (MI) [5]. This entails that two sideband pairs, equally detuned by the most unstable perturbation frequency from the FF and DF, may spontaneously grow from noise. MI is commonly believed to occur only in cubic media through four-photon interactions involving the decay of two pump photons into down and up-shifted photon twins. Conversely we anticipate that MI may occur with cascaded nonlinearity via combined three-photon processes. A photon at frequency 2ω0 produces a photon pair at frequencies (ω0 − Ω, ω0 + Ω), whereas photons at the sideband frequencies 2ω0 ± Ω are created by annhilating two photons at frequencies ω0 and ω0 ± Ω, respectively.
Soliton polarization rotation in fiber lasers
Authors: Afanasjev V. V.
Published: February 2023

Over the past few years there has been considerable research undertaken into the problem of soliton propagation in birefringent fibers [1-5]. It was found that solitons are stable against birefringence, i.e. soliton polarization components couple through cross-phase modulation and the two-component (vector) soliton propagates as a single unit [1]. Vector solitons have been observed numerically [1, 2, 4] and experimentally [3, 5].
Periodic conjugation of optical solitons
Authors: Goedde Christopher G. , Kath William L. , Kumar Prem
Published: February 2023

Optical phase conjugation of a linear pulse to compensate for the effects of even-order dispersion was first proposed by Yariv et al.1 and recently demonstrated.2 If a pulse is conjugated at the fiber midpoint, subsequent propagation reverses the effects of even-order dispersion. Recently, Forysiak and Doran3 showed that mid-point optical phase conjugation can be used in optical soliton transmission systems to compensate for soliton-soliton interactions and Gordon-Haus jitter.
Sub-Femtosecond Pulses in 2π-Solitons of the Cascade Stimulated Raman Scattering
Authors: Kaplan A. E.
Published: February 2023

The shortest to date optical pulse length of 6 fs [1] was achieved by using pulse compression technique. Further shortening could be attained by using a Fourier synthesizer [2] of separate lasers synchronized by nonlinear phase-locking [3]. Here, we propose a new approach [4] based on multi-frequency cascade Raman stimulated scattering (CSRS) whose components are mode-locked within 2π soliton reminiscent to the self-induced transparency solitons [5], We show that Raman active materials can support solitons consisting of pump laser wave with the frequency ω
L
and many cascade-excited Stocks and anti-Stocks component with their frequencies ω
j
= ω
L
+ jω0, j =±1, +2, +3…, mode-locked to each other through a fast "full­swing" 2π-nutation of population at the Raman transition with the frequency ω0 ≪ ω
L
. Similarly to "bright-bright" 2π-solitons in CSRS with two [6] and three [7] components, these solitons have a new, very simple, Lorentzian intensity profile. Due to the engagement of many mode-locked components, however, their total EM field in the time domain consists of the train of ultra-short pulses (separated by the interval 2π/ω0) with their length being of the same order of magnitude or even shorter than the pump cycle, 2π/ω
L
. The major feature of the proposed effect is that all the frequency components of the new soliton are so called bright solitons (in contrast to the well known bright+dark soliton combination in SRS [8]) locked to each other and propagating with the same group velocity. The high-order CSRS required to observe the proposed effect, was first observed experimentally in [9] and later in many other experiments, with the total number of components up to ~10-15. The lock-in of all these components into "all-bright-SRS" 2π soliton, however, has never been observed in experiment; its feasibility and resulting effects are discussed here.