FIELD: physics; optics.
SUBSTANCE: invention relates to optical focusing systems compatible with different types of data carriers. The optical focusing system comprises a diffraction element and a lens for focusing light onto data carriers. The said diffraction element has at least first and second diffraction surfaces, where the first diffraction surface diffracts light with wavelength of 630 nm or more, and 670 nm or less for aberration correction at the data carrier, the coating section of which has thickness of approximately 0.6 mm; and the second diffraction surface diffracts light with wavelength of 400 nm or more, and 415 nm or less for aberration correction at the optical data carrier, the coating section of which has thickness of approximately 0.1 mm or approximately 0.6 mm.
EFFECT: aberration correction on several types of data carriers.
14 cl, 12 dwg, 3 tbl
