Аннотация:Femtosecond laser structuring of dielectrics is currently a high-priority task for creation of optical elements. In the present work, we report on femtosecond laser nanostructuring of the surface of calcium fluoride leading to formation of self-organized periodic ripples with a sub-wavelength period of about 200 and 350 nm. The dependence of structure period on the wavelength of laser radiation corroborated by the results of simulation is established. The structures exhibit reduced transmitance in entire visible range mainly due to diffraction and scattering of light.