摘要 |
FIELD: optics. ^ SUBSTANCE: element has Bragg phase grid, which is formed in electric-optical material or in additional layer applied to it. Grid is provided with means for forming non-homogenous non-periodic outer electric field along direction of optical radiation movement, by means of which diffraction efficiency of grid is determined. Optical elements system has at least two Bragg phase grids, having different periods and placed serially along direction of movement of optical radiation. System of optical elements is controlled by effecting on grids with non-homogenous non-periodic outside electric field. ^ EFFECT: higher efficiency. ^ 4 cl, 29 dwg |