Biomedical subjects

Paolo Di Porto

Publications and source records attributed to Paolo Di Porto.

4 recordsLinked to original sources

PubMed2004

Electromagnetic nondiffracting pulses in lossless isotropic plasmalike media.

We introduce a scheme for describing electromagnetic nondiffracting pulses propagating in isotropic and lossless media characterized by a plasma-like refractive index. A family of nondiffracting waves in a dispersive medium is analytically derived in the form of a generalization of X waves propagating in vacuum. It is also shown how the ratio between pulse width and plasma length has a crucial effect on the pulse dynamics.

Journal Article↗

PubMed2004

One-dimensional nondiffracting pulses.

A general expression describing nondiffracting pulses whose transverse profile is a one-dimensional image is presented. The pulse turns out to be expressed as a superposition of two fields, possessing a purely translational dynamics, whose profiles are related to the field distribution on the the waist plane through an Hilbert transformation. The space-time structure of the generally X-shaped pulse is investigated and a simple relation connecting its transverse and the longitudinal widths is established. Specific analytical examples are considered and, in particular, the fundamental one-dimensional X waves are deduced and compared to their two-dimensional counterparts.

Journal Article↗

PubMed2004

Vector electromagnetic X waves.

A vector propagation scheme for describing electromagnetic nondiffracting beams (X waves) is introduced. In particular we show that, from the knowledge of the transverse field components on a given transverse plane and at a fixed instant, it is possible to predict the whole electric field everywhere which in particular allows us to investigate the imaging properties of nondiffracting beam. Furthermore, we show that the longitudinal field component crucially depends on the pulse velocity and that it can be neglected only if the velocity is slightly greater than c. The proposed formalism is tested by means of two examples, the vector fundamental and Gaussian X waves which admit analytical treatment. As an application of the propagation scheme, we derive in closed form the expressions for the field propagator showing that its transverse component formally coincides with one of the scalar fundamental X wave.

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PubMed2004

Universal space-time properties of X waves.

Exact results concerning spatiotemporal universal features of three-dimensional propagation-invariant solutions of the wave equation (X waves) are derived. In particular, relations connecting the pulse transverse extension to the longitudinal coordinate and the propagation velocity to the spatial field distribution are obtained for the whole class of X waves.

Journal Article↗