| Abstract [eng] |
Phase plates – optical elements which are widely used in most of the systems which consist of polarized light. They intended to control the light – change the polarization state, control the intensity of the light, change the spatial distribution of the pulse etc. Anisotropic crystals, polymers, liquid crystals and other layers with anisotropic properties can be used in production of such elements. Most of these elements are difficult to produce, they are fragile with low resistance to environmental conditions. Phase plates produced by “Serial bi-deposition” method do not consist any of these drawbacks. Thin anisotropic films made by glancing angle deposition are being investigated for more than 20 years but there is still a lack of investigations for production of phase plates on thin substrates and micro optics. In present work we report the investigations of two materials – TiO2 and Al2O3 as appropriate for evaporation of optical elements. TiO2 has the highest refractive index among materials suitable for visible light spectrum and Al2O3 is transparent material in ultraviolet light with high refractive index. For high quality production of phase plates, a thin film has to exhibit phase delay and low inner stress. The tendencies of the coating properties and the optimal parameters for phase plates production were investigated. Nano-structured thin films were measured with spectroscopic ellipsometry. The intensive phase delay was established for layers deposited at higher than 30 degrees evaporation angles. For both materials phase delay reaches the maximum value at 70 degree deposition angle. Nano-sculptured thin films made of TiO2 and Al2O3 by electron beam evaporation technique show that the inner stress depends on the evaporation angle. Increasing the angle of deposition the tensions are changing from positive to small valued negative and reach the minimal value, less than 10 MPa, when evaporated at 80 degree. According to the results of this work, high quality wave plates can by evaporated by “Serial bi-deposition” technique. Optical elements with high optical transparency and small tensions can be produced for visible and ultraviolet light applications. |
