Plasma channel generation (or filamentation) using ultraintense laser pulses in dielectric media has a wide spectrum of applications, ranging from remote sensing to terahertz lightning control. So far, filamentation been triggered with the use ultrafast axially symmetric spatial beam profiles, thereby generating straight filaments. We report experimental observation curved plasma channels generated air femtosecond Airy beams. In this unusual propagation regime, tightly confined main...

A four-level model which takes account of the polarization laser field by including spin sublevels conduction and valence bands a semiconductor allows us to introduce vector rate equations for degree freedom emission. Analysis these their extension include transverse degrees provides important physical insight into nature instabilities in surface-emitting lasers. In absence effects predicts marginally stable linearly polarized state. The type dynamical response is linked relative time scale...

Spatial- and time-domain versions of the unidirectional pulse propagation equation (UPPE) are derived compared from point view their practical application in simulations nonlinear optical dynamics. A modification UPPE suitable for ultrathin waveguides, such as submicron silica wires, is also presented. We show detail how various, previously published equations follow a unified way that clearly elucidates underlying approximations areas applicability.

Summary form only given.We present numerical simulations of nonlinear pulse propagation in air to elucidate the physical mechanism phenomenon. Our comprehensive model for ia includes effects self-focusing multiphoton absorption, group-velocity dispersion (GVD), absorption and defocusing due generated electron density.

The onset and recurrence of multiple light filaments during the long-distance propagation intense femtosecond infrared pulses in air is shown to share features with strong turbulence other physical systems. Here, however, space-time collapse events drive turbulence, plasma defocusing, not dissipation, dominant mechanism regularizing collapse.

Pattern formation in large aspect ratio, single longitudinal mode, two-level lasers with flat end reflectors, operating near peak gain, is shown to be described by a complex Swift-Hohenberg equation for class A and C coupled mean flow the case of B laser.

A theory is presented that describes the global reflection and transmission characteristics of a self-focused channel propagating at an oblique angle incidence to interface separating two or more self-focusing nonlinear dielectric media. The wave packet representing represented as equivalent particle moving in potential. dynamics described by Newton's equations motion, with asymptotic propagation paths being read off from associated phase portraits Equilibria potential, equivalently,...

A unidirectional optical pulse propagation equation, derived directly from Maxwell's equations, provides a seamless transition between various nonlinear envelope equations in the literature and full vector equations. The equation is illustrated context of supercontinuum generation air compared to recent scalar model Brabec Krausz. Fully vectorial aspects are extreme focusing femtosecond pulse.

The space-time behavior of a wide-gain-section, single-longitudinal-mode laser is investigated. Analysis the full Maxwell-Bloch model in one transverse spatial dimension identifies traveling-wave solution beyond first threshold, for positive detuning from resonance, which appears to be globally attracting state laser. On negative-detuning side we observe an initial bifurcation homogeneous plane-wave state. A second instability threshold can identified by linearizing about respective...

Fully microscopic many-body models are used to study the importance of radiative and Auger carrier losses in InGaN∕GaN quantum wells. found be negligible contrast recent speculations on their for experimentally observed efficiency droop. Good agreement with measured threshold is demonstrated. The results show no significant dependence details well alloy profile.

Recent experiments on femtosecond pulses in water displayed long distance propagation analogous to that reported air. We verify this phenomena numerically and show the is dynamic as opposed self-guided. Furthermore, we demonstrate can be interpreted due nonlinear X-waves whose robustness role shown follow from interplay between nonlinearity chromatic dispersion.

We report experiments on the propagation of intense, femtosecond, self-bending Airy laser beams in water. The supercontinuum radiation generated along curved beam path is angularly resolved far field. Spectral maps this reveal changing character laser-pulse evolution propagation.

Phase-locked solitary waves are shown to be the stable fixed points of an infinite-dimensional map obtained from a bistable optical ring cavity.Received 13 April 1983DOI:https://doi.org/10.1103/PhysRevLett.51.75©1983 American Physical Society

A model based on density-activated defect recombination processes is proposed as a possible explanation for the efficiency droop in GaN-based lasers. The yields very good agreement with experimentally measured efficiencies fit parameters that indicate presence of two types centers have different local distributions and rates. rates are found to be similar devices operating at 530nm 410nm.

We present a continuous wave terahertz source based on intracavity difference frequency generation within dual color vertical external cavity surface emitting laser. Using nonlinear crystal with phase matching scheme allows for high conversion efficiencies. Due to the tunability of mode spacing, entire spectral range gap can be covered. The output scales quadratically intensity, potentially allowing intensities in 10s milliwatts and beyond.

In this article, we develop a classical electrodynamic theory to study the optical nonlinearities of metallic nanoparticles. The quasi-free electrons inside metal are approximated as Coulomb-interacting electron gas, and their motion under excitation an external electromagnetic field is described by plasma equations. This further tailored second-harmonic generation. Through detailed experiment-theory comparisons, validate well associated numerical algorithm. It demonstrated that our not only...

We report experiments and numerical simulations on supercontinuum generation with femtosecond Airy pulses in a highly nonlinear optical fiber. The ability of the waveform to regenerate its dominant intensity peak results distinct spectral features. other self-healing temporal waveforms may be useful for spectra desired properties.

A new class of instabilities for a plane-wave intracavity field in an optical ring resonator is identified. Dynamical systems techniques are explained and applied to the map. bifurcation diagram given that organizes important information, global pictures developed describe evolution attractor its basin boundary. Anomalous behavior observed earlier numerical studies explained.

A quantum-well vertical-external-cavity surface-emitting laser in combination with a SESAM is used to generate femtosecond pulses. The passively modelocked VECSEL operates at room temperature emitting an average output power of 5.1 W 1030 nm. At repetition rate 1.71 GHz, the 682 fs pulses are nearly transform limited.

The temperature dependence of the measured internal efficiencies green and blue emitting InGaN-based diodes is analyzed. With increasing temperature, a strongly decreasing strength loss mechanism responsible for droop found which in contrast to usually assumed behavior Auger losses. However, experimental observations can be well reproduced assuming density activated defect recombination with independent time.

The influence of propagation on the nonperturbative high-harmonic features in long-wavelength strong pulse excited semiconductors is studied using a fully microscopic approach. For sample lengths exceeding wavelength exciting light, it shown that effectively acts as very additional dephasing reduces relative height emission plateau up to six orders magnitude. This induced clarifies need use extremely short polarization decay times for quantitative analysis experimental observations.

Higher-order optical harmonics entered the realm of nanostructured solids being observed recently in gratings and metasurfaces with a subwavelength thickness. Structuring materials at scale allows us toresonantly enhance efficiency nonlinear processes reduce size high-harmonic sources. We report observation up to seventh harmonic generated from single resonator made AlGaAs material. This process is enabled by careful engineering geometry for supporting an mode associated quasi-bound state...