Search

In this Letter, we investigate giant and negative bistable lateral shifts for a light beam transmitted through a one-dimensional photonic crystal containing a nonlinear metamaterial defect. It is shown that there exists a typical S-shaped curve of the normalized input–output intensity. The hysteresis of lateral shift, resulting from the reshaping effect (constructive and destructive interferences of each plane wave components undergoing different phase shifts) is dependent on the nonlinear defect, the incident intensity and incidence angle. Numerical simulations are also made for the validity of stationary phase approach. All these phenomena lead to potential applications in integrated optics and optical switches.

Using a omega-3 omega combination scenario, we investigate the absolute phase control of the spectra effects for ultrashort laser pulses propagating in a two-level medium. It is found that the higher spectral components can be controlled by the absolute phases. In particular, different absolute phase combinations can lead to the buildup or split of the even harmonics. (c) 2006 Elsevier B.V. All rights reserved.

We investigate the large negative lateral displacements of TE polarized light beams reflected from or transmitted through an active slab surrounded by transparent medium. The large negative displacements can be achieved when the incidence angle of the beam is less than but close to the critical angle for total reflection. It is also shown that both the reflectivity and transmissivity of the beam that correspond to the large negative displacements can be enhanced by active medium. These phenomena may lead to convenient measurements and interesting applications in optical devices.

The lateral displacement of electron beams transmitting through a two-dimensional semiconductor barrier is quite different from the prediction from Snell's law for electron waves. It is shown that the displacement can be greatly enhanced by transmission resonance when the incidence angle is less than but close to the critical angle for total reflection. The displacement depends not only on the barrier's thickness but also on the incidence angle and the incidence energy. The influence of electron's effective mass is also discussed. Theoretical results of the stationary-phase approach are confirmed by numerical simulations for a Gaussian-shaped incident beam. These phenomena may lead to novel applications in quantum electronic devices.

A parameter, called the degree of paraxiality, is introduced upon examining the property of energies originating from the longitudinal as well as the transverse components of both the electric and magnetic fields. It is shown that this degree of paraxiality is determined by the magnitude of the plane-wave spectrum, without depending on the vectorial feature of the plane-wave spectrum. Its value ranges from 0 to 1. A larger value stands for a more paraxial beam. As an application, two examples are considered.

It is reported that the phase time of particles passing through a potential well is negative when the energy of incident particles and the thickness of potential well satisfy certain conditions. Similar results are also found in a fully-relativistic optical analog. The 2-dimensional optical case gives rise to a lateral shift of the wave packet. It is shown that the phase-time associated lateral shift can also be negative.