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We used a Fourth-Order Runge-Kutta in the Interaction Picture Method for simulating supercontinuum generation (SCG) in a designed solid-core photonic crystal fiber (PCF) with zero dispersion wavelength (ZDW) at 800 nm and other solid-core PCF with ultra-flattened dispersion in the range of 1300 nm to 1550 nm obtaining a SCG with a bandwidth of 850, 1200, and 2300 nm using a femtosecond laser in the three communication windows. Here we achieved ZDW close to the first, second and third communication windows which gives us the possibility to obtain a wide spectrum at these points with good quality in the 40-dB bandwidth for SCG with flat spectrum. The design of the two PCFs proposed here is analyzed numerically using finite element method (FEM) and we showed the results when we used a pump wavelength in normal and anomalous dispersion regimes close to ZDW points of these two PCFs for SCG.

Here we propose a simple design for a photonic crystal fiber using the golden ratio parameter of pitch and four rings with hexagonal structure of air holes with solid core of silica. By varying the ratio of air hole diameters inside the structure we can control the range of flattened dispersion in anomalous or normal dispersion regime close to zero dispersion wavelength (ZDW). The wide range of wavelengths of 1.19–1.83 μm with small losses for chromatic dispersion of −0.34 ± 0.66 ps/(nm-km) and 1.292–1.555 μm with chromatic dispersion of 0 ± 0.06138 ps/(nm-km), can allow the possibility of use in different engineering areas, such as supercontinuum generation, pulse reshaping, and dense-WDM (DWDM) based optical communication systems.

This paper presents the design of all-normal dispersion photonic-crystal fiber optimized for pulse-preserving supercontinuum generation near 800 nm. The supercontinuum generation is analyzed numerically addressing the role of pump pulse energy and the pump wavelength deviation from the zeroth point of third-order dispersion. We have also shown that supercontinuum generated in designed ANDi-PCF from a few nanojoule 100 fs pulses can be efficiently compressed down to a sub-10-fs pulse with a simple quadratic compressor.

El tópico de este artículo, abordará la investigación de una técnica novedosa para la compensación electrónica de la dispersión en comunicaciones por fibra óptica a larga distancia, en la cual una señal es pre-compensada eléctricamente usando un modulador diferencial Mach-Zender, controlado por filtros digitales no lineales. La dispersión cromática fue efectivamente compensada con el uso del conjugado de fase óptica en el transmisor a través de los 4000 Km de fibra mono modo (carente de no-linealidad y atenuación) en donde la dispersión es compensada para una señal de NRZ (no retorno a cero) de intensidad modulada a 10 Gb/s. La compensación de la dispersión fue confirmada midiendo la razón de error de bit y observando los diagramas de ojo detectados.

High intensities electromagnetic energy interacting with organic media gives rise to nonlinear optical effects. Hibiscus Sabdariffa is a flower whose concentrated solution presents interesting nonlinear optical properties. This organic material shows an important self-phase modulation with changes bigger than 2π. We present a diffraction ring patterns study of the Hibiscus Sabdariffa solution. Numerical results of transmittance, with refraction and simultaneous absorption, are shown.

We show experimental results for the propagation of a diffracted beam by a straight edge like initial condition in a photorefractive crystal under drift nonlinearity. We have observed that the diffracted pattern and propagation is enhanced in the form of multiple waveguides.

In this paper, design and characterization of a pH optical fiber sensor with pH sensitive dye is described. The sensor is prepared by fixing the doped plastic fiber on a fused ortosilica block surface with blue bromophenol. The surface charge of silica and the refractive index, which plays an important roll on the fiber, modifies the conditions of light propagation into the plastic optical fiber. We use the transmittance to measure the pH of a solution or fluid in a range between 5.0 and 7.0. The advantage of this sensor is that, only 2 cm of doped fiber is enough to measure the pH of a fluid in real time. The time response of the sensor reported in the present study is approximately 10 s.

Photonic crystals are periodic structures of the dielectric materials where is posible manipulate photons in many interesting ways. Photonic band gap can propagate specific wavelengths. We present the design of demultiplexer based in photonic crystals. The control of the dielectric materials, periodicity, and size of the dielectric, is very important for light propagation. In optical communications we need to work with 1.31μm and 1.55μm by the total dispersion and due to the minimum dispersions inside the fiber and therefore minimum loses. Our design of the demultiplexer is based on diference between the background and rod refractive index.

In this work the implementation of a sensor of optical fiber current is reported by means of a magnetic structure. The sensing element (magnetic structure) consists of a magnet placed in the center of a plastic membrane. The variation in the intensity of the light caused by a mirror adapted to the membrane allowed to detect the changes in the presence of a magnetic field produced by an alternating current. Its changes were detected optically. We design a circuit to convert the light to equivalent in data to be process by a PC. The data are read and by means of a program in software Labview®, is the equivalent of current according to the intensity of detected magnetic field. INTRODUCTION Accelerated changes in technology of systems of communications and arrival of systems optical that of way they replace to systems electronic that is used in this type of systems, have influenced to a great extent, so that we takes to the optic and in special case optical communications, like the door that opens new breaches and produces a great field of the investigation [2,3]. Many electronics devices like logic gates, elements of commutation and sensors, they have been replaced by optical fiber devices that have revolutionized of considerable way and which they surpass some restrictive of the electronic systems. The optical fibers are an average ideal to be used in atmospheres of high voltage of equal way, are ideal for the information transmission and taking advantage of this property also it is possible to be created devices that help us to take measurements. The conventional electrical systems are often inadequate in surroundings of high tensions and zones with interferents, local fields of industries with emanations, the optical fiber does not create east problem to us. The sensors of current based on optical fibers, are devices that are being studied and that have obtained good results [1]. ISSN 0040-2508 © 2005 Begell House, Inc. 691 J.M. ESTUDILLO-AYALA, R. ROJAS-LAGUNA,J.A. MARTIN-VELA E. ALVARADO-MENDEZ... The electronics devices to measure current discharges but unfortunately they are very expensive and that can well be alternative that they little by little allow to develop and to innovate sensors us of current done with optical fiber designed in schools of engineering for applications in electrical substations in the country, and measurements in the laboratory with greater exactitude. The sensors of current based on optical fiber have received a special attention in the recent years. This must to its immunity to the electromagnetic fields mainly; its hostile, low atmosphere robustness lost by the transmission of signals in long distances, possibility the multiplex of several signals, adjustable length of the sensible element, great bandwidth and dynamic range. They provide complete galvanic isolation when being an average dielectric; do not circulate around them electrical signals. DESIGN AND OPERATION Theory The sensor element consisted of a magnet placed in the center of a plastic membrane. The change in the intensity of the light caused by the mirror adapted to the membrane allowed to detect the changes in the presence of a magnetic field produced by an alternating current. If the implemented structure this located to a certain distance D of an electrical line driver, an electrical intensity Ielec, would be a force of Lorentz in the magnet. This force can be expressed like: m F MV H = ∇ . (1) With M and Vm being the magnetization and the volume of the magnet, respectively, and being the gradient of associated magnetic field to Ielec, the position of the magnet. If an ideal load line is considered, magnetic field H generated by Ielec to a distance D can be expressed in cylindrical coordinates like: ˆ 2 elec I B H u D θ μ π = = (2) from this expression, H ∇ it can be obtained like: 2 ˆ 2 elec r I H u D π ∇ = (3) In the equation 1 sample which the force that acts in the magnet indicates the direction of , that this throughout the radial axis. H ∇

Here we propose a simple design for a solid-core photonic crystal fiber made of silica by keeping the golden ratio (1.618) between pitch and air hole diameter Λ /d in a subset of six rings of air-holes with hexagonal arrangement. In the case when we have a pitch equal to one micron (Λ =1 μm), we need air-holes diameters d=0.618 μm in order to obtain the golden ratio parameter (Λ/d=1.618), and achieve two zero dispersion wavelength (ZDW) points at 725 nm and 1055 nm; this gives us the possibility to use this fiber in supercontinuum generation using a laser emission close to that points. We analyzed a series of fibers using this relation and show the possibilities of tunable ZDW in a wide range of wavelengths from 725 nm to 2000 nm with low losses and small effective area. In agreement with the ZDW point needed, the geometry of the structure can be modified to the point of having only three rings of air holes that surround the solid core with low losses and good confinement mode. The design proposed here is analyzed using the finite element method (FEM) with perfectly matched layers (PML), including the material dispersion directly into the model applying the Sellmeier’s equation.

We have numerically investigated the supercontinuum generation and pulse compression in a specially designed all-normal dispersion photonic crystal fiber with a flat-top dispersion curve, pumped by typical pulses from state of the art Ti:Sapphire lasers at 800 nm. The optimal combination of pump pulse parameters for a given fiber was found, which provides a wide octave-spanning spectrum with superb spectral flatness (a drop in spectral intensity of ~1.7 dB). With regard to the pulse compression for these spectra, multiple-cycle pulses (~8 fs) can be obtained with the use of a simple quadratic compressor and nearly single-cycle pulses (3.3 fs) can be obtained with the application of full phase compensation. The impact of pump pulse wavelength-shifting relative to the top of the dispersion curve on the generated SC and pulse compression was also investigated. The optimal pump pulse wavelength range was found to be 750nm < 𝜆𝑝 < 850nm, where the distortions of pulse shape are quite small (< -3.3 dB). The influences of realistic fiber fabrication errors on the SC generation and pulse compression were investigated systematically. We propose that the spectral shape distortions generated by fiber fabrication errors can be significantly attenuated by properly manipulating the pump.

We study numerically and experimentally the reflection of spatial solitons at the interface between a nonlinear saturable-type medium and a linear one. We emphasize on determining the physical conditions under which the reflected beam at the interface conserve its nondiffracting properties. Depending on the incidence angle, we find three critical regions for spatial soliton conservation after reflection. We numerically show that the nonlinear Goos–Hanchen shift can have a dramatic effect on the diffracting properties of the reflected beam.

We show that when the coherent superposition of two dark spatial solitons is used as the initial condition for an optical beam, it will form an asymmetric optical Y-junction after evolution in a nonlinear Kerr-like medium. Using a computer-generated holographic mask to provide such a required initial condition, we demonstrated that an asymmetric optical Y-junction can be formed in a photorefractive BTO crystal.

Experimental observations of 1D and 2D self-focusing in a BaTiO3 crystal under externally DC applied electric field are reported. Stationary self-focusing behaviour can be obtained with and without additional uniform illumination.

The effect of nonlinear polarization rotation in a fiber loop mirror constricted from a low-birefringent fiber was numerically examined. We have shown that it provides in itself the intensity variation of the transmission coefficient from 1 to 0 in the configuration with a 0.5 0.5 coupler and a birefringent bias rotating polarization by π 2 at one end of the fiber. By appropriate choice of the fiber parameters both normal and inverted characteristics of the interferometer can be achieved.

We reported Supercontinuum (SC) generation in standard telecom fiber using picosecond pulses of microchip laser. The pulses width is 700 ps at 1064 nm, using 57 m long of standard fiber, and the spectra extend from 700 to above 1700 nm, some 100 nm further into the visible. The physical processes leading to the formation of the continuum spectrum were studied by monitoring the growth of the SC while increasing the input power. The coupling efficiency of ours experimental setup between the microchip laser and the telecom fiber helped us to obtain this wide spectrum.

Supercontinuum generation is being widely studied due to its applications in communications, medicine and metrology. Usually, special fibers, such as photonic crystal fibers and dispersion-shifted fiber, have been utilized. However, there is few information about the potential use of standard fiber with this purpose, which shows some advantages: low cost and availability. In this work, the influence of losses due to induced macrobends on the supercontinuum generation using standard fiber was studied. The losses were introduced by wrapping 30 m in length of standard fiber on cylinders with different diameter, a nanosecond microchip laser and 1064 nm of wavelength were employed. The continuum was recorded at the fiber output by using an optical spectrum analyzer and its dynamics was analyzed by tuning the launched power. In a first stage, the fiber was used without bends generating strong firs-order Raman Stokes and a supercontinuum spectrum of 636 nm. When the fiber was wrapped in a cylinder of 0.9 cm of diameter to induce macrobends, the Raman Stokes of high order were attenuated and the output spectrum was reduced to 240 nm. Also, a peak pulse was observed, around 1030 nm, that means new frequencies were generated in the near infrared region. Thus, induced macrobends affect the supercontinuum broadening.

The compact laser sources with ultra-broad spectrum or specially shaped pulse waveforms are significant for science and industry, and the need for these sources can be satisfied using the fiber-optic platform. We present results on transformation of ultrashort optical pulses in different types of optical fibers aiming synthesis of specially shaped pulses and single-pulse flat-top supercontinuum

Formation of triangular ultrashort optical pulses is demonstrated theoretically. Quality of those pulses and their properties are discussed.

This article presents the fabrication of Long Period Gratings in Optical Fiber (LPFGs) applied to the sensing loops. In implementing the manufacturing method used a commercial splicer fiber optic (FiTel S-175), capable of being programmed to a short section of standard optical fiber (SMF28) is taken at intervals between shots in a range from 400µm to of 650µm. The LPFGs Being able to obtain through attenuation bands above 20 dB, while the wavelength of central attenuation is close to 1550nm. We shows the experimental scheme to measure curvatures with diameters ranging between 12 and 13.1cm, having a linear variation of peak output cut at the LPFGs with tuning of 17nm.

We investigated numerically the reflectivity of aperiodic multilayer mirrors for broadband supercontinuum reflection. It was shown that multilayer mirror based on TiO 2 /SiO 2 with layer thicknesses changed in the nonlinear way can provide high reflectivity from 468 nm to 1600 nm.

We study de nonlinear optical properties of organic materials. Multiple rings appear as a CW Ar laser passes through a nonlinear organic liquid. The rings formation is due to spatial self-phase modulation and is observed with 50 mW of continuous wave of Ar laser. We show the dependence between power and rings formed. As a first approximation to value the nonlinear refractive index we use the number of the rings and power of laser in a cell of 2 mm of length.

We propose the fabrication and characterization to bending and temperature of a long period fiber grating with the alternative electric arc method known as fattening. This is the enlargement of the fiber structure by means of arc discharges from a commercial splicing machine. The fiber structure consists of 4 layers of glass of different refractive index. The resulting device is a reject band filter with an attenuation band around 1400nm. It has a bandwidth of 162nm with a depth around 26.9 dB. Test to bending depict changes in band depth up to -10dB between radii values of 4-7cm with a shifting span of 16.8nm. Temperature characterizations are made with bending and straight fiber over a hot surface. Interesting achievements can take advantage as optical sensors with different characteristics. Optimization in the fabrication process can be achieved to lower the insertion losses so better sensors can be applied for industry and commercial applications.

Nonlinear effects are consequence of interaction of height intensities of energy with the matter. Self-diffraction is nonlinear effect and rings are produced. We analyzed the increase of rings due to changes in intensity of CW Ar laser that modify the nonlinear refractive index. The Carbon Nanotubes (CNTs) were dispersed on different solvents: a) water, b) ethanol, c) isoprophanol, and d) acetone. The concentrations were 10ml:1mg in all samples. The dependence between power and concentration of CNTs is shown.

Refinement of spectral characteristics of chirped mirrors with numerical optimization algorithms is presented. We discuss different forms of merit function. Conjugate gradient method for numerical optimization is used for improvement of single chirped mirrors design as well as chirped mirrorspsila pair. A novel technique based on variation of Bragg wavelength curvature is proposed in order to achieve target phase shift. It allows us to manipulate the dispersion curve of a chirped mirror and particularly half period shift of quasiperiodic GDD resulted in subtraction of GDD oscillations. This is important for designing of complementary chirped mirrorspsila pair.

In this work we present the formation of dark photonic lattices in negative nonlinear medium. Bright periodic lattices are generated by interference technique and propagated through 1 cm of length of nonlinear medium (R6G with acetone). The dependence with the laser (Ar) power and the geometry selected are showed. Three very interesting cases were obtained: two dimensional dark photonic lattices (2D), one dimensional dark photonic lattices, and (1D), and 2D and 1D combination effects. Our experimental results are accord with numerical simulations.

A numerical simulation investigation of a carrier-suppressed return-to-zero differential phase-shift keying (CSRZ-DPSK) with an adaptive recursive least square (RLS) filter at the receiver side is reported.

In this paper we propose a high voltage source which is controlled by a communication port I/O of a data acquisition card. The graphical programming language LabView is employed for this task. We make use of this source to produce optical fiber gratings by inducing an electric arc with the point by point procedure. It has a control section to modify the arc duration time and thus the voltage and current applied to the fiber by means of two electrodes. The experimental setup by which we characterized the gratings is depicted and we also present the transmitting spectrum. The gratings were fabricated with SMF-28 fiber but microstructured fiber can be exploited too. These gratings can be used with optical fiber lasers as optical filters and in the implementation of optical sensors.

We demonstrate that periodic lattice arrays can be formed by interferometry patterns. An advantage of this system is the possibility of change different geometries of periodic lattice arrays only varying the mirror of the experimental setup. The patterns can be recorded in a special film emulsion and we studied the photonic band-gaps for different geometries.

We demonstrate the using of 1D nonlinear photonic crystals to intensity sensing of high-power optical signals and for optical power limiting. The analytical expression for dependence of the reflectivity on the radiation intensity is presented.

In this paper, the Bragg mirrors manufactured of the macroporous silicon infiltrated with liquid crystals are investigated. The reflectance spectrum of the structure is calculated using a transfer matrix method. The influence of the applied alternating field on reflectance spectrum of the structure is considered. The comparative analysis of the Bragg lattices reflectance spectra with different anisotropy of liquid crystals is realized when the voltage is applied. The opportunity of combination of the porous silicon layers infiltrated with positive or negative anisotropy of the liquid crystals is discussed

Design and characterization of a pH optical fiber sensor with a pH sensitive dye is described in this paper. TEOS (Tetra-ethyl-Orto-Silicate) was used to dope a plastic optical fiber, which will be used as the optical probe (OPTRODE). The sensor is prepared by fixing the doped plastic fiber on a fused ortosilica block surface with blue bromophenol. The fiber surface charged with silica modified the refractive index, which plays an important roll on the fiber, modifies the conditions of light propagation into the plastic optical fiber. The fiber transmittance is used to measure the pH of a solution or a fluid in a range between 4 and 7; such signal is captured by a photodetector and processed with a LabView program. The advantage of this system is that, 2cm of doped fiber are enough to measure the pH of a fluid in real time. The time response of the se nsor reported in the present study is approximately 10s. Keywords: Doped fiber, Optical fiber Sensor; pH sensor; Sol-Gel. 1. INTRODUCTION Many industrial sectors have as a need a distributed measurements system for chemical parameters. Early detection and location of water or fluids filtration, for example, could prevent premature damage to cables in both communications and power distribution ducts, in foods industry, biological systems, etc.[1-2]. The detection of some parameters, such pH decreasing to the value of 10, can be a good indicator of potential corrosion of reinforcing tensors in civil engineering structures which are on earth, underground or under water conditions. The definition of pH is the concentr ation of hydrogen ions in liquids. If the pH value is between 0 and 7, are called acids. If the pH values between 7 and 14 are called bases. For pH = 7 the substances are called neutrals, for example pure water, where is very important monitoring for our health. Some biological systems have ionic groups which electrical charge depends on pH concentration; this pH value depends on the balance between the O-H and H. Ther efore, pH is sensitive to the ions concentration in

The photonic crystal (PC) coupler and planar photonic band gap (PBG) coupler were theoretically investigated. Also the conventional step-index coupler was investigated for comparison with these couplers. The PC-coupler is a structure formed by the gradual tapering of the photonic-crystal holey fiber and the conventional step-index coupler -- by the gradual tapering of the conventional fiber. The planar PBG-coupler is a planar PC waveguide, in which defect region has taper-like geometry. The photonic crystal couplers are characterized by alternation of the material refractive index along the wave propagation direction, i. e. along the optical axis of the taper. In our investigation an effective refractive index model for two-dimensional photonic crystal was used. This model allows to analyze the waveguide structures, which work on the effective index waveguiding in a defect of the photonic crystal. The optical field in photonic crystal couplers, PBG couplers and conventional couplers was investigated. Also losses and mode shape distortion of all types of the couplers were calculated.

At the present paper the photonic crystal coupler of an optical fiber, which has been made by the adiabatic tapering of the optical fiber based on the photonic crystal is presented. In our investigation an effective refractive index model of two-dimensional photonic crystal was used. This model allows analyzing the waveguide structures, which work on the effective index waveguiding in a defect of the photonic crystal. The effective refractive indexes of such couplers were numerically found. Using this model the field distribution in these couplers were investigated and were calculated its losses. It was shown that the couplers with smaller input diameter and the fixed output diameter have smaller losses.

This paper is about a numerical investigation of the NOLM (non optical loop mirror) with low birefringence fiber and a0.5/0.5 coupler. We induce birefringence to the loop fiber bias macro bendings considering self rotation polarization of the input beam. This is done in order to find its possible advantages as an optical switch.Keywords: bhfi1ngere,nonhinearqlicalloop * CONACYT Scholarship L INTRODUCHON Birefringence is a single mode fiber characteristic due to core asymmetry. Its effect is the discomposure of an electricalfield in its orthogonal components with a little difference in phase and with a particular polarization. It is also induced by torsion or bending because of the photo elastic effect. For the bending case, an index refraction asymmetry is made,inducing so, the birefringence effect [8]. In this paper, we intend to undertake birefringence basic theory, as to recall investigations made to date about the birefringence effect by means of torsion. This will subsequently lead us to a basicinvestigation of the auto rotation polarization when inducing birefringence by bending a fiber and to analyze differencesbetween torsion and macro bends in the fiber. Thus, we shall achieve a basic investigation contribution about the themeto support later studies and applications.2. ThEORICAL CONSIDERATIONS

We present the polarization dependence in the formation of dark spatial waveguides in nonlinear liquids like CS2. Our experimental and numerical results about the formation of dark waveguides show the dependence between the polarization and the formation of multiple waveguides. With a polarization angle between 100° - 120° for the incident beam we show that the wide of the waveguide is minimum and even dark spatial waveguides are formed. A discussion about waveguides formation is presented for others polarization angles. In this work we show an improvement in the method to measure low birefringence in optical fibers.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this work we showed an improvement in the method to measure low birefringence in optical fibers with the Sagnac interferometer published in paper previous in which the fiber twists in an end of the loop of the interferometer and the entrance of the light every time it is adjusted that twists the fiber. In this work we twist the fiber in the center of the loop of the Sagnac interferometer it is very simple and we don't need light polarization neither to adjust the axes in the entrance of the fiber. It can use for the mensuration a section of shorter fiber that a beat length. Some theoretical and experimental results are presented.

Spatial optical solitons have been suggested for all optical guiding and switching in nonlinear-optical media. One of their more promising characteristics for practical applications in photonics are the structures formed by intersecting waveguides such as X or Y junctions. Such intersecting waveguides can be implemented by colliding two or more solitons. Recently collision between mutually incoherent 2D spatial solitons in a SBN crystal was reported, interacting forces between one-dimensional spatial solitons in parallel propagation were observed, and the fusion and birth of 2D spatial solitons caused by the collision and annihilation of photorefractive solitons was reported. Other techniques for optical switching can be implemented using effects like total internal reflection of solitons in an interface formed by a nonlinear and a linear medium

The Sagnac interferometer of twisted low-birefrigence fiber is analyzed numerically in the lineal region. A method for measuring the birefringence of the fiber and the angle of rotation of the axes inside the fiber loop of the interferometer is also presented.

In this work we have shown that Stimulated Raman Scattering can be effectively controlled by a fiber bending losses resulting in spectral dependence of the fiber attenuation.

An experimental investigation of the dynamical, time depends effects in the reflection of (2+1)D beam at the nonlinear interface between photorefractive crystal SBN61:Ce and a linear medium is performed. Our study make emphasis on determining the physical condition under which the beam reflected by the interface is still a focusing beam.

We analyze linear and no linear optical properties of PMMA clusters in thin film s with Ni nanoparticles dispersed with different concentrations. Saturable absorber and negative nonlinear refraction index behavior evidences were found using z-scan technique. We also show that these properties have not dependence of the type of matrix but they have on concentration.

We study experimentally the behavior of 1D and 2D spatial solitons in a SBN61:Ce photorefractive crystal under drift nonlinearity. In this report, we show experimental observation of optical branching effect for 1D beams and anisotropic self-focusing effect for 2D beams when we applied an appropriate external electric field along the c- axis of the photorefractive crystal.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We study the reflection of two-dimensional spatial solitons at the nonlinear interface between a saturable nonlinear medium (photorefractive crystal) and a linear medium. Our study places emphasis on determining the experimental conditions under which the beam reflected by the nonlinear interface is still a spatial soliton.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this letter, we present an experimental investigation of the influence of light attenuation produced by bending on the generation of Stokes pulse.

We present a numerical study of the reflection of one-dimensional spatial solitons at non-linear interface between a photorefractive medium and a linear medium. In this work, we have considered that non-linear medium is governed by both;drift and diffusion mechanisms. Our study places emphasis on determining the physical conditions under which the beamreflected is still a spatial soliton. The beam is deflected into the interface using the self-bending effect. Introduction Photorefractive crystals (PRC) provided some amazing nonlinear features for low powers light beams. Almost 7 years ago,the first interaction between one-dimensional spatial solitons and PRC was experimentally showed by Duree' et. al. andIturbe2 et. al. for different types of non-linearity. After this, several effects related with solitons in PRC have been studied inorder to develop ultra-fast commuters and optical logic gates3. In the same way, reflection effect of beam light in twodifferent media, when at least one of the media exhibits some kind of optical nonlinearity4 (Kerr, saturable, quadratic, etc.),has been extensively studied5 Recently, Alvarado6 et. al. determined the physical condition under which a spatial soliton isobtained after reflection by an interface non-linear-linear.In this paper we analyze, from numerical and the theoretical point of view, the behavior of one-dimensional brightspatial soliton in a PRC governed by both non-linearities; drift and diffusion, as it reaches the boundary whit a linear mediumusing self-bending effect7.

In this paper a tunable multi-wavelength erbium doped fiber laser, based on a Mach–Zehnder interferometer, is presented. Here the interferometer is achieved by splicing a piece of photonic crystal fiber (PCF) between two segments of a single-mode fiber. The laser can emit a single, double, triple or quadruple line, which can be tuned from 1530 to 1556 nm by controlling the polarization state. Finally it is shown, by experimental results, that the laser has high stability at room temperature.

We study experimentally and numerically the transient behavior of a (2+1)D beam when it is totally reflected by nonlinear interface formed by SBN61:Ce photorefractive crystal. The dynamics give rise to observation of new beams. Due to modulation instability of the beam, the nonlinear interface stimulates the break of the beam into new beams that are reflected to different angles.

The authors experimentally demonstrate self-diffraction effect in a hybrid material. Patterns at different light intensity levels were obtained. A dependence of the number of diffraction rings with the intensity of laser is observed.