JA - Elektronika a optoelektronika, elektrotechnika
CEP
GA102/01/0429 GA ČR - Grantová agentura ČR
CEZ
AV0Z2067918 - URE-Y
Anotace
Nondiffracting beams have been in the center of interest for the last decade. These beams, however, can be realized in practice only approximately. The simplest scheme for generating such a beam is to use a sufficiently narrow annular source placed in the back focal plane of a lens. Behind the lens, the beam is pseudo-nondiffracting in some length. The inverse problem is detection of Čerenkov radiation. The trace of a charged particle travelling through a dielectric medium faster than light emits this radiation under a certain angle. Generated conical wavefront creates in the back focal plane of a lens a diffraction pattern in form of a ring. The contribution analyses theoretically both mentioned problems.
