33 research outputs found
Laser-to-proton energy transfer efficiency in laser-plasma interactions
It is shown that the energy of protons accelerated in laser-matter
interaction experiments may be significantly increased through the process of
splitting the incoming laser pulse into multiple interaction stages of equal
intensity. From a thermodynamic point of view, the splitting procedure can be
viewed as an effective way of increasing the efficiency of energy transfer from
the laser light to protons, which peaks for processes having the least amount
of entropy gain. It is predicted that it should be possible to achieve \apprge
100% increase in the energy efficiency in a six-stage laser proton accelerator
compared to a single laser-target interaction scheme
Resonant transparency of materials with negative permittivity
It is shown that the transparency of opaque material with negative
permittivity exhibits resonant behavior. The resonance occurs as a result of
the excitation of the surface waves at slab boundaries. Dramatic field
amplification of the incident evanescent fields at the resonance improves the
resolution of the the sub-wavelength imaging system (superlens). A finite
thickness slab can be totally transparent to a \textit{p}-polarized obliquely
incident electromagnetic wave for certain values of the incidence angle and
wave frequency corresponding to the excitation of the surface modes. At the
resonance, two evanescent waves have a finite phase shift providing non-zero
energy flux through the non-transparent region