74 research outputs found
Accelerated rogue waves generated by soliton fusion at the advanced stage of supercontinuum formation in photonic crystal fibers
Soliton fusion is a fascinating and delicate phenomenon that manifests itself
in optical fibers in case of interaction between co-propagating solitons with
small temporal and wavelengths separation. We show that the mechanism of
acceleration of trailing soliton by dispersive waves radiated from the
preceding one provides necessary conditions for soliton fusion at the advanced
stage of supercontinuum generation in photonic crystal fibers. As a result of
fusion large intensity robust light structures arise and propagate over
significant distances. In presence of small random noise the delicate condition
for the effective fusion between solitons can easily be broken, making the
fusion induced giant waves a rare statistical event. Thus oblong-shaped giant
accelerated waves become excellent candidates for optical rogue waves.Comment: Optics Letters Journal. In pres
The fundamental solution of unidirectional pulse propagation equation
In the article the fundamental solution of a variant of wave equation known as ``unidirectional pulse propagation equation'' (UPPE) and its paraxial approximation is obtained. It is shown that the fundamental solution can be presented as a projection of a fundamental solution of the wave equation to some functional subspace. We discuss the degree of equivalence of UPPE and wave equation in this respect. In particular, we show that UPPE, in contrast to the widespread belief, describes the wave propagation in both directions simultaneously, and remark non-causal character of its solutions
Scar-like structures and their localization in a perfectly square optical billiard
We show that scar-like structures (SLS) in a wide aperture vertical cavity surface emitting laser (VCSEL) can be formed even in a perfectly square geometry due to interaction of polarization and spatial degrees of freedom of light. We show also that dissipation in the system induces an order among the cavity modes, so that SLS become preferred at lasing threshold. More generally, modes which are more localized both in coordinate and momentum space have in average lower losses
Non-Poissonian statistics in an optical analog of quantum billiard with perfectly square boundaries
We study deviation from the Poissonian statistics of the frequency spacing distribution, appearing due to coupling of polarizational and transverse degrees of freedom in a perfectly square vertical cavity surface emitting laser. The deviation can be controlled by strength of the intracavity anisotropy and its alignment to the device boundaries
Scar-like structures and their localization in a perfectly square optical billiard
We show that scar-like structures (SLS) in a wide aperture vertical
cavity surface emitting laser (VCSEL) can be formed even in a perfectly
square geometry due to interaction of polarization and spatial degrees of
freedom of light. We show also that dissipation in the system induces an
order among the cavity modes, so that SLS become preferred at lasing
threshold. More generally, modes which are more localized both in coordinate
and momentum space have in average lower losses
Quasi-phase-matching for third harmonic generation in noble gases employing ultrasound
We study a novel method of quasi-phase-matching for third harmonic
generation in a gas cell using the periodic modulation of the gas
pressure and thus of the third order nonlinear coefficient in the
axial direction created by an ultrasound wave. Using a comprehensive
numerical model we describe the quasi-phase matched third harmonic
generation of UV (at 266 nm) and VUV pulses (at 133 nm) by using
pump pulses at 800 nm and 400 nm, respectively, with pulse energy in
the range from 3 mJ to 1 J. In addition, using chirped pump pulses,
the generation of sub-20-fs VUV pulses without the necessity for an
external chirp compensation is predicted
Stability of quantum linear logic circuits against perturbations
Here we study transformation of waveshapes of photons under the action of the linear logic circuits and other related architectures involving only linear optical networks and measurements. We show that the gates are working well not only in the case when all photons are separable and located in the same mode, but in some more general cases. For instance, the photonic waveshapes are allowed to be slightly different in different channels; in this case, Zeno effect prevents the photons from decoherence after the measurement, and the gate thus remains neutral to the small waveshape perturbations. © 2020 The Author(s). Published by IOP Publishing Ltd Printed in the U
Generation of terahertz radiation from ionizing two-color laser pulses in Ar filled metallic hollow waveguides
The generation of THz radiation from ionizing two-color femtosecond
pulses propagating in metallic hollow waveguides filled with Ar is
numerically studied. We observe a strong reshaping of the
low-frequency part of the spectrum. Namely, after several
millimeters of propagation the spectrum is extended from hundreds of
GHz up to ~THz. For longer propagation distances, nearly
single-cycle near-infrared pulses with wavelengths around 4.5~m
are obtained by appropriate spectral filtering, with an efficiency
of up to 0.25~\%
Rotational symmetry breaking in small-area circular vertical cavity surface emitting lasers
We investigate theoretically the dynamics of three low-order transverse modes in a small-area vertical cavity surface emitting laser. We demonstrate the breaking of axial symmetry of the transverse field distribution in such a device. In particular, we show that if the linewidth enhancement factor is sufficiently large dynamical regimes with broken axial symmetry can exist up to very high diffusion coefficients 10 um^2/ns
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