A binary silicon diffractive optical element (DOE) focusing laser radiation onto an axial segment (or a DOE with elongated focal depth) for the terahertz spectral range has been designed and characterized using terahertz radiation of the Novosibirsk Free Electron Laser (NovoFEL).

A review on studies and applications of the beams with orbital angular momentum (vortex or twisted beams) is presented. First experimental results on the formation of vortex beams in the terahertz spectral range using a free electron laser is described.

В рамках скалярной теории дифракции с использованием параксиальной и непараксиальной моделей показано, что дополнение линзы слабым аксиконом или логарифмическим аксиконом позволяет придать фокальной области вид конуса, остриё которого имеет меньший поперечный размер, чем фокальное пятно отдельной линзы. Использование в качестве рабочей части этого заострённого конца при углублении остальной части фокуса в подложке позволит повысить разрешение в приложениях многофотонной полимеризации.

The novel binary radial diffractive optical element (DOE) forming light bottle intensity distributions in the zero diffractive order has been designed and experimentally studied. The microparticle's optical trapping is realized by use of manufactured DOE. It is shown that realized light bottle can be used for trapping transparent and non-transparent microparticles in viscous medium.

The numerical procedure for optimization of binary diffractive optical elements forming light distribution “light bottle” is developed and investigated . The developed numerical procedure is based on modification of well-known genetic algorithm. The results of numerical experiments are presented.

This paper deals with application of the known gene tic stochastic procedure to determine the optimum of the function of many variables to designing quantized DOEs forming pre-given intensity distribution along an axial focal zone. Computer simulation results are presented.

The technology of formation difracting microrelief at an end face of a polycrystalline IR-optical path (PIR-optical path) is investigated. Influence of errors of technology of formation of a divider of the bunch realized at a target end face of an optical path, on the set distribution intensity of difracting orders is considered. Recommendations on improvement of characteristics of a formed microrelief are formulated.