We present a novel experimental technique that can differentiate unequivocally between chaotic light and coherent light with amplitude fluctuations, and thus permits us to characterize unambiguously ...the output of a laser. This technique consists of measuring the second-order intensity cross correlation at the outputs of an unbalanced Michelson interferometer. It is applied to a chaotic light source and to the output of a semiconductor nanolaser whose "standard" intensity correlation function above threshold displays values compatible with a mixture of coherent and chaotic light. Our experimental results demonstrate that the output of such lasers is not partially chaotic but is indeed a coherent state with amplitude fluctuations.
Nonlinear dynamical systems involving small populations of individuals may sustain oscillations in the population densities arising from discrete changes in population numbers due to random events. ...By applying these ideas to nanolasers operating with small numbers of emitting dipoles and photons at threshold, we show that such lasers should display photon and dipole population cycles above threshold, which should be observable as a periodic modulation in the second-order correlation function of the nanolaser output. Such a modulation was recently reported in a single-mode vertical-cavity surface-emitting semiconductor laser.
In this study, the nonlinear dynamics of nanoparticle concentration in a colloidal suspension (nanofluid) were theoretically studied under the action of a light field with constant intensity by ...considering concentration convection. The heat and nanoparticle transfer processes that occur in this case are associated with the phenomenon of thermal diffusion, which is considered to be positive in our work. Two exact analytical solutions of a nonlinear Burgers-Huxley-type equation were derived and investigated, one of which was presented in the form of a solitary concentration wave. These solutions were derived considering the dependence of the coefficients of thermal conductivity, viscosity, and absorption of radiation on the nanoparticle concentration in the nanofluid. Furthermore, an expression was obtained for the solitary wave velocity, which depends on the absorption coefficient and intensity of the light wave. Numerical estimates of the concentration wave velocity for a specific nanofluid—water/silver—are given. The results of this study can be useful in the creation of next-generation solar collectors.
By exploiting the unique properties of periodic stratified media we demonstrate simultaneously phase matching and enhancement of the optical field under second order nonlinear interaction. This leads ...to a second harmonic efficiency growth faster than the fifth power of the structure length, far better than the usual quadratic behavior associated with second order nonlinear effects.
Catastrophes in nature and society Khlebopros, Rem G; Khlebopros, Rem G; Okhonin, Victor A ...
2007., 2007, 20070214, 2003-12-16, 2007-02-14
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Many people are concerned about crises leading to disasters in nature, in social and economic life. The book offers a popular account of the causative mechanisms of critical states and breakdown in a ...broad range of natural and cultural systems — which obey the same laws — and thus makes the reader aware of the origin of catastrophic events and the ways to avoid and mitigate their negative consequences. The authors apply a single mathematical approach to investigate the revolt of cancer cells that destroy living organisms and population outbreaks that upset natural ecosystems, the balance between biosphere and global climate interfered lately by industry, the driving mechanisms of market and related economic and social phenomena, as well as the electoral system the proper use of which is an arduous accomplishment of democracy.
Two independent photons, produced through the spontaneous emission of two separate emitters subject to uncorrelated dephasing processes, can display two-photon interference (i.e. coalescence into a ...two-photon state) when they are incident simultaneously on a beamsplitter, in a manner analogous to that of twin photons produced through degenerate parametric fluorescence. The presence of dephasing processes, however, reduces the interference contrast (i.e. the probability of coalescence), by the ratio of the coherence time to the lifetime of the emitter.
We present atomic-scale characterization of site-controlled InAs/InP(001) quantum dots grown by metal-organic chemical vapor deposition using nano-area selective area growth. We have developed for ...this purpose a process combining e-beam lithography, inductively coupled-plasma etching and focused ion beam etching to isolate a few quantum dots. The size, the shape and the composition of the quantum dots are investigated by Scanning Transmission Electron Microscopy. A comparison with the well-known single self-assembled quantum dots highlights the specificities of our growth mode compared to the Stranski–Krastanov growth mode.
► Structural study of site-controlled quantum dots by Scanning Transmission Electron Microscopy. ► Processing of site-controlled quantum dots for a deterministic observation by transmission electron microscopy. ► Determination of the composition of InAs(P)/InP site-controlled quantum dots by Energy Dispersive X-Ray measurements.
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