Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking [1,2]. To achieve spatial cloaking, the index of refraction is manipulated to flow light from a probe around an object in such a way that a "hole" in space is created, and it remains hidden [3][4][5][6][7][8][9][10][11][12][13][14]. Alternatively, it may be desirable to cloak the occurrence of an event over a finite time period, and the idea of temporal cloaking was proposed in which the dispersion of the material is manipulated in time to produce a "time hole" in the probe beam to hide the occurrence of the event from the observer [15]. This approach is based on accelerating and slowing down the front and rear parts, respectively, of the probe beam to create a well controlled temporal gap in which the event occurs so the probe beam is not modified in any way by the event. The probe beam is then restored to its original form by the reverse manipulation of the dispersion. Here we present an experimental demonstration of temporal cloaking by applying concepts from the time-space duality between diffraction and dispersive broadening [16]. We characterize the performance of our temporal cloak by detecting the spectral modification of a probe beam due to an optical interaction while the cloak is turned off and on and show that the event is observed when the cloak is turned off but becomes undetectable when the cloak is turned on. These results are a significant step toward the development of full spatio-temporal cloaking.

The synchronization of human networks is essential for our civilization and understanding its dynamics is important to many aspects of our lives. Human ensembles were investigated, but in noisy environments and with limited control over the network parameters which govern the network dynamics. Specifically, research has focused predominantly on all-to-all coupling, whereas current social networks and human interactions are often based on complex coupling configurations. Here, we study the synchronization between violin players in complex networks with full and accurate control over the network connectivity, coupling strength, and delay. We show that the players can tune their playing period and delete connections by ignoring frustrating signals, to find a stable solution. These additional degrees of freedom enable new strategies and yield better solutions than are possible within current models such as the Kuramoto model. Our results may influence numerous fields, including traffic management, epidemic control, and stock market dynamics.

Synchronization in large laser networks with both homogeneous and heterogeneous coupling delay times is examined. The number of synchronized clusters of lasers is established to equal the greatest common divisor of network loops. We experimentally demonstrate up to 16 multicluster phase synchronization scenarios within unidirectional coupled laser networks, whereby synchronization in heterogeneous networks is deduced by mapping to an equivalent homogeneous network. The synchronization in large laser networks is controlled by means of tunable coupling and self-coupling.

We study experimentally and theoretically the interactions among ultrashort optical pulses in the soliton rain multiple-pulse dynamics of a fiber laser. The laser is mode-locked by a graphene saturable absorber fabricated using the mechanical transfer technique. Dissipative optical solitons aggregate into pulse bunches that exhibit complex behavior, which includes acceleration and bi-directional motion in the moving reference frame. The drift speed and direction depend on the bunch size and relative location in the cavity, punctuated by abrupt changes under bunch collisions. We model the main effects using the recently proposed noise-mediated pulse interaction mechanism, and obtain a good agreement with experiments. This highlights the major role of long-range Casimir-like interactions over dynamical pattern formations within ultrafast lasers.Dissipative solitons are localized waves in open systems far from equilibrium, whose existence results from a balance of dissipative and dispersive effects. They appear in numerous physical areas including reaction-diffusion systems, neurological and ecological sciences, fluid dynamics, and photonics [1,2]. In photonics, spatial dissipative solitons are stabilized by dynamical attractors and evolve like discrete particles in effective media [3]. A major challenge in their study is the distillation of an effective low-dimensional dynamical system governing pulse position and speed [4], which would determine the temporal evolution of multiple-pulse patterns. This implies an effective modeling of pulse interactions whose range and complexity are determined by the physical system. Mode-locked fiber lasers exhibit an extensive pallet of short and long-range pulse interactions. The former take place when pulse tails overlap [5][6][7][8], and the latter when pulses interact over separations orders of magnitude beyond their individual extension -and are hence mediated. In fiber lasers, where slow gain depletion and recovery dynamics create an effective long-range repulsive force [9] solitons pulses distribute equally along the cavity (harmonic mode-locking) [10]. Other interactions can be mediated by perturbations of an extended background field or propagation medium (e.g. electrostriction [11,12]).

In this review the wide spectrum of properties of filled polymer systems is generalized. Classical and modern conceptions dealing with the influence of the boundary layer and filler on melting and crystallization of the polymer matrix. Polymer properties in the melted and condensed state are considered, attention being given to the influence of the filler particle size and shape, the nature of its surface, its structure, and agglomeration on the theological and mechanical characteristics of composites.Data on structure and properties of filled thermoplastic composites are summarized for the first time. Special attention is paid to the peculiarities of composites with modified polymerized filler behavior during rheological and mechanical testing and processing of such composites. IntroductionPolymeric composite materials (PCM) belong to one of the most important classes of structural materials attracting ever growing interest, as manifested by the huge flow of published scientific and technical information dealing with the problems of developing, preparing, processing and using PCM [1]. Whereas the oil and gas fuel crisis has receded recently, the problem of their restrained use still remains an urgent one if only because the oil and gas reserves are not unlimited and practically non-reproducible. Estimates by specialists have shown [2,3] that the development of PCM with a view to cut the consumption of polymeric materials can only be economically feasible if not less than 15% by volume of the filler are added.Waste products from a number of commercial processes can be used as cheap and readily available fillers for PCM. For example, lightweight structural materials may be obtained by filling various low-viscous resins with waste materials [4,5]. Also by adding fillers to reprocessed polymers it is possible to improve their properties considerably and thus return them to service [6]. This method of waste utilization is not only economically feasible but also serves an ecological purpose, since it will help to protect the environment from contamination. The maximum percentage of the filler should in these cases be such as to assure reliable service of the article made from the PCM under specified conditions for a specified period of time.However, the chief purpose of introduction of fillers into PCM is to make possible the modification of polymers and thereby create materials with a prescribed set of physico-mechanical properties, and, obviously, the properties of filled materials may be controlled by, for example, varying the type of the base polymer (the "matrix") and filler, its particle size distribution and shape. It may not require a large quantity of filler [7]. Thanks to considerable advances in PCM research, their use in a broad range of industries -machine building, construction, aerospace technology, etc. -has become extensive [8][9][10][11].Development of an assortment of polymeric composite materials, decSsions concerning their possible scope of applicability and service conditions involve research in...