ABSTRACT
We demonstrate a scheme for tunable shaping of a soliton spectrum. Specifically, we show a local enhancement of 6 dB in the pulse spectrum by propagating the pulse through a fiber containing micro-bends generated by a flexural acoustic wave - an acoustic long-period grating (LPG) - followed by nonlinear propagation through uniform fiber. The location of the enhancement peak can be tuned by external control of the acoustic frequency of the LPG. We discuss the potential application of this scheme to tunable supercontinuum sources.
ABSTRACT
The interaction of two rectangular pulses in the nonlinear Schrödinger model is studied by solving the appropriate Zakharov-Shabat system. It is shown that two real pulses may result in an appearance of moving solitons. Different limiting cases, such as a single pulse with a phase jump, a single chirped pulse, in-phase and out-of-phase pulses, and pulses with frequency separation, are analyzed. The thresholds of creation of new solitons and multisoliton states are found.
ABSTRACT
We propose the use of nonlinear four-wave mixing as a means of trapping light in a defect state in a nonuniform fiber grating. The amount of energy deposited is estimated by use of an approach similar to Fermi's "golden rule" and is approximately 30 fJ for realistic grating parameters and a pulsed pump of 100-ps width.
ABSTRACT
Oscillations in the one-dimensional chain consisting of rotatorlike particles levitating in a plasma are studied. General equations of motion for such a chain are derived. It is demonstrated that new oscillation modes associated with the rotational degrees of freedom appear for such a configuration. The dispersion characteristics of the modes are analyzed. Collective oscillations and equilibrium in lattices composed of cylindrical particles in a plasma are discussed.
ABSTRACT
The dynamics of solitary waves in ferroelectric liquid crystals is considered in the context of an overdamped double sine-Gordon model. Various possible types of single waves are studied. The dependence of wave velocity and scale on the system parameters and initial conditions is found. Sharp initial profiles lead to waves with a universal form. The parameters of the wave arising from smooth profiles are determined also by the scale of the initial conditions. Numerical calculations show good agreement with analytical results. The possibility of using such waves to improve the characteristics of liquid crystal devices is also discussed.
