Bright and dark solitons in the normal dispersion regime of inhomogeneous optical fibers

In this letter, under investigation is a nonlinear Schrödinger equation with varying dispersion, nonlinearity and loss for the propagation of ultra-short optical pulses in the normal dispersion regime of optical fibers. By virtue of the modified Hirota's method and symbolic computation, the analytic two-soliton solution is explicitly obtained. Both the bright and dark solitons are observed in the normal dispersion regime of optical fibers with dispersion management. An asymptotic analysis to verify the elastic collision between solitons is performed and the stability of the soliton solutions is investigated. Besides, a new bright solitonic generator for generating high-power and narrow bandwidth pulses is advised. Furthermore, possible applicable soliton control techniques which might be used for the design of optical switch and dispersion-managed systems are proposed.     

Combined optical solitons with parabolic law nonlinearity and spatio-temporal dispersion

In this work, combined optical solitons are constructed in a weakly nonlocal nonlinear medium. The spatio-temporal dispersion (STD), parabolic law nonlinearity, detuning, nonlinear dispersion as well as inter-modal dispersion are taken into account. The integration tool that is applied is the complex envelope function ansatz. The influences of different parameters on dynamical behavior of combined optical solitons are discussed. The results are useful in describing the propagation of combined optical solitons with STD and parabolic law nonlinearity.     

Tailored dispersion profile in controlling optical solitons in a tapered parabolic index fiber

We investigate the soliton dynamics in tapered parabolic index fibers via symbolic computation for a variety of dispersion profiles to inspect how a specific dispersion profile controls the optical soliton. By means of AKNS procedure, Lax pair is constructed for nonlinear Schrödinger equation with variable coefficients. Using obtained Lax pair, multi-soliton solutions are generated via Darboux transformation technique. Using multi-soliton solutions, soliton dynamics in tapered parabolic index fiber with the hyperbolic, Gaussian, exponential, and linear profiles are discussed. Results obtained in this study will be of certain potential application on construction of the nonlinear optical devices by soliton control. Results obtained in this study will be of certain value to the studies on the propagation and application of the soliton in the tapered parabolic index fiber and dispersion-managed fiber system.     

Characteristics of the etching of undoped silica in MCVD-fabricated optical fibers with buffered hydrofluoric acid

The etching reaction between the undoped silica cladding in MCVD-fabricated fibers and buffered hydrofluoric acid (BHF) has been studied by examining the outer diameter decrease of the fibers in a given etching time. The study has revealed that the etching reaction is not diffusion limited. The etch rate is determined and compared with values published for SiO₂ - films. We have also determined the activation energy of the process, which agrees well with values reported for SiO₂ - films.     

Propagation of solitary waves in inhomogeneous erbium-doped fibers with third-order dispersion,self-steepening and gain/loss

We propose a generalized inhomogeneous Hirota–Maxwell–Bloch system which explains ultrashort optical pulse propagation in an inhomogeneous nonlinear, dispersive fiber doped with two-level resonant atoms. For this system, higher order effects like third-order dispersion and self-steepening are considered, which are assumed to be inhomogeneous together with group velocity dispersion and self-phase modulation. We have obtained a general solitary wave solution by using Lax pair and Bäcklund transformation techniques. We have analyzed various solitary wave forms like snaking solitons, classic solitons and compressed pulses by controlling the physical parameters and inhomogeneous functions.     

Directional laser generation and detection of ultrasound with arrays of optical fibers

Some aspects of the generation and detection of ultrasound with laser beams are presented. The objective of the study is (1) to present some experimental results on the generation of ultrasound with an array of optical fibers, (2) to discuss the possibility of generating directional surface waves with acousto-optic scanning in a very narrow frequency band, thus increasing the signal-to-noise ratio, and (3) to discuss the feasibility of the directional detection of ultrasound by using an array of optical fibers as a receiver, also with the goal of increasing the signal-to-noise ratio.     

New phospho-tellurite glasses with optimization of transition temperature and refractive index for hybrid microstructured optical fibers

The glass formation and compositional dependences of glass thermal properties and optical properties were investigated in TeO₂–ZnO–Na₂O–P₂O₅ system. The refractive index at 1.55 μm and glass transition temperature varied in a wide range from 1.513 to 2.036 and from 265 °C to 376 °C by controlling of the TeO₂/P₂O₅ and ZnO/Na₂O content, respectively. These properties enable phospho-tellurite glasses with large freedom in designing and fabrication of hybrid microstructured optical fiber. The structures of glasses were investigated by Raman spectra to understand their dependence of structure on composition. Using the present glasses, some hybrid microstructured optical fibers with various dispersion profiles were designed.