Based on numerical experimental techniques, we demonstrate the possibility to control light by light in nonlinear arrays of subwavelength dielectric parallel waveguides. To reach our goal, we work with waveguides of different cross sections: circular and square. Characteristic dimensions of waveguides are in the order of half of the carrier wavelength, and propagation distances are more than hundreds of wavelengths. We show that with the proper selection of parameters it is possible to obtain light self-trapped in a single waveguide that will allow us to study the optical fields’ interaction in the array. The main result that we discuss here is that we can control the light output position for two input beams. The light behavior is a function of the phase difference and incidence angle, as well as the light power at the input of the array.
We study the dynamics of nonlinear propagation and interaction of two optical fields in arrays of dielectric subwavelength waveguides of circular cross section. Applying the finite-difference time-domain (FDTD) method, we numerically solve the Maxwell's equations considering real values for the constitutive relations. The arrays under study include a finite number of parallel waveguides with identical parameters. In our study, we focus on the light self-trapping conditions. For that, we define the properties of the incident optical fields: complex amplitude, wavelength, angle of incidence and phase difference values. As a result, we observe the strong dependence of the energy output to input critical parameters: phase difference and angle of incidence. We conclude about the possibility to generate a single output beam. The output signal position depends on the nonlinear interaction properties and is controlled by the selection of the system parameters. These results may contribute to the development of logic gates based on subwavelength waveguides.
The multiple functions and potential applications of nanotechnology have become a necessary and powerful tool in
scientific work everyday. Nanotechnology is interdisciplinary science involving physics, chemistry, biology, materials
science and wide range of engineering disciplines. His versatility has led to an increasing use in wide range of fields. For
example, electronic engineering has shown an interest growing in the design of nanodevices due to continued
miniaturization of them. The investigations have focused on the manufacture of electronic circuits and their applications
complex systems, in addition to this, nanotechnology already plays an important role in
development of new materials with tailored features and chemical properties, so their study is important today.
Nanosensors have been under investigation for some institutions in recent years. A nanosensor is a device built on an
atomic scale based on measurements nanometers, whose purpose is mainly to obtain data on the atomic scale transfer so
they can be easily analyzed. In this work We study wave propagation in a low-dimensional planar nano-waveguide, to
establish the principle of operation of an optical structure to propose the design of a nanosensor.
Based on the numerical experiment techniques, we addressed this work to the study of the physical
parameters, which allow the discrete soliton formation and propagation in two dimensional
waveguide arrays of different geometries. The mathematical model is based on the two
dimensional nonlinear Schrödinger equation, and from the boundary conditions we are able to
conclude that the array geometry plays an important role in the energy demands for the discrete
soliton formation and propagation over distances of hundreds of diffraction lengths. Furthermore,
our results are consistent even in the case when we take into account coupling of higher orders.
We present an overview of the main properties and the emerging implementations corresponding to a photopolymerizable glass modified with high refractive index species (HRIS) incorporated at molecular level. The study concerns to transmission and reflection holograms in Bragg and Raman-Nath regimens and polarization properties of
gratings with high spatial frequencies are also analyzed demonstrating a strong dependence of the refractive index
modulation with the polarization state of the reading beam. Not limited to the study of the optical properties of the
photopolymerizable glass we propose two applications of the holographic material. The first one is the fabrication of
polarizers elements with high performance at low cost such us holographic polarizers and holographic polarizers beam splitters. The second application concerns to the holographic recording of stables modes exhibiting high diffraction efficiency. Also, we have recently extended our studies to ultrashort pulse lasers in femtosecond regime. The photopolymerizable gratings are good candidates as optic elements to beam manipulation of ultrashort pulse lasers.
This document shows the presence of photonic band gaps on the dispersion curves of the TE and TM modes of a two
concentric core optical fiber. Such a fiber presents two concentric cores where it is assumed that guided modes exist.
We report the experimental synchronous pulse generation in a multicavity fiber laser system with two Erbium-doped
fiber laser cavities. We have demonstrated that through the evanescent fields interaction between one cavity with active
modulation and other one in continuous wave it is possible to generate more intense pulses in both cavities. Moreover,
the synchronous pulse generation between cavities is achieved with an appropriate selection of pump intensity,
modulation frequency and coupling ratio. We found that the pulse intensity is 2.5 times greater and the pulse duration
lowers than a single Erbium-doper fiber laser. Furthermore, by means of the synchronous diagram we determined the
synchronization strength in temporal pulse emission between cavities.
In this paper we developed a simplified numerical averaging algorithm in order to obtain exactly periodic solutions of the non-linear Schrodinger equation (NLSE) with periodically varying coefficients. We calculate the pulse shape of the true dispersion-managed soliton, and show its long term stable propagation. This simplified model constitutes a variant of the original method much easier to program.
A variational method with an arbitrary ansatz is used to reduce the governing equation in the case of a periodic dispersion-managed fiber system to a coupled set of nonlinear ordinary differential equations. The phase-plane dynamics of the reduced system and the main characteristics of the dispersion managed pulses, namely the possibility of propagation when the average dispersion is zero or normal, are examined.
Dispersion curves of the modes TE y TM of a two concentric core optical fiber are presented. This fiber, in contrast to multi clad-one, has a layer where it is assumed that guided modes exist. The main characteristic of such a curves is that they are discontinuous.
The objective of this work is to study, numerically and experimentally the waveguide properties of dark spatial soliton arrays generated in photorefractive media. Experimentally we produced the dark solitons using a He-Ne laser beam and a photorefractive BTO crystal under external electric field to excite the drift nonlinearly. The beam to be guided was obtained from a semiconductor laser at a wavelength where the photorefractive effect was lower. This probe beam was focused in different regions and at different angels with respect to the array. The result obtained shown that the guiding ability of the array depends on the period, the external field and the probe beam angle. Numerical simulations solving the nonlinear Schrodinger equations are in correspondence with the experimental observations.
In this paper, we report the numerical study of the synchronous soliton-like pulses generation in a multichannel
fiber laser system, conformed by an array of 2 up to 7 coupled Erbium doped fibers, separately pumped. The pulse
synchronous generation is obtained by means of an amplitude modulator inserted in one of the channels, and the
energy interaction of evanescent waves between this channel and all the others.
Numerically we demonstrate the self-starting mode locking, in a dual core ring fiber laser. Our mathematical model takes into account Kerr nonlinearity, the group velocity dispersion, the full gain line for the active ions, the pump depletion, and the feedback of the passive core.
Analytical expression for the possible oscillation frequencies generated by a single-mode linear-cavity fiber laser are presented. The mathematical model takes into account dispersion and nonlinear self-phase modulation.
Analytical results of the stimulated Raman self-scattering influence on the propagation of femtosecond optical solitons are presented. The spectral perturbation method is developed, and we show that this method allows us to obtain a quantitative estimation of the frequency shift for an arbitrary relation between the parameters of the soliton pulse and the Raman line.
Generation of ultrashort pulses in an actively mode-locked fiber laser are investigated analytically and numerically. Utilization of soliton pulse shaping makes it possible to shorten the output pulse width by more than one order of magnitude without loss of average power.