defined polarization state is a key requirement in numerous photonic applications. For example, linear optical polarizers are frequently utilized in lithography, [7,8] industrial vision, [9] microscopy, ellipsometry [10] or astronomic remote sensing systems. [11] All these applications substantially benefit from efficient nano-optical wire grid polarizers.A wire grid polarizer (WGP) is a grating type metasurface (see Figure 1). The typical operation principle for such elements requires the transmittance of TM polarized light T TM (TM transversal magneticelectrical field orthogonal to the ridges) to be much larger than that of TE polarized light T TE (transversal electric-electrical field parallel to the ridges) to achieve a significant anisotropic filter functionality. Here, the extinction ratio E r = T TM /T TE is used to express the suppression of TE polarized light. [12] WGPs are highly beneficial because of large achievable element sizes (wafer size), compactness (wafer thickness), and large acceptance angles. [13] Furthermore, their nano-optical nature allows an easy integration into other (nano-)optical elements, such as litho graphy masks, [14] enabling local polarization control. Currently, applications advance toward shorter wavelengths in order to benefit from smaller foci and characteristic electronic transitions, which can be utilized for material analysis. While WGPs are well established in the VIS and IR, suitable ones were not available in the deep ultraviolet (DUV) spectral range until very recently. [12,15,16] The lack of applicable DUV WGPs originates from challenging requirements on both structure and material properties.A structural period of the polarizer has to fulfilling the zero order conditionto avoid propagation of diffraction orders greater than the zeroth one.[17] For a normal incidence of light (ϕ = 0°) with a wavelength λ in the DUV and a fused silica substrate with a refractive index n sub a period p in the order of 100 nm is necessary. Additionally, an aspect ratio (see Figure 1: ratio of height and ridge width) larger than five is typically required. [12] The simultaneous realization of large aspect ratio and small periods is technologically extremely challenging. Fortunately however, advances in nanotechnology do allow the fabrication of such structures. [18] Pelletier et al. [15] demonstrated aluminum WGPsWire grid polarizers (WGPs), periodic nano-optical metasurfaces, are convenient polarizing elements for many optical applications. However, they are still inadequate in the deep ultraviolet spectral range. It is shown that to achieve high performance ultraviolet WGPs a material with large absolute value of the complex permittivity and extinction coefficient at the wavelength of interest has to be utilized. This requirement is compared to refractive index models considering intraband and interband absorption processes. It is elucidated why the extinction ratio of metallic WGPs intrinsically humble in the deep ultraviolet, whereas wide bandgap semiconductors are superior materia...

To cite this version:DAbstract. The atmospheric pressure dielectric barrier discharge burning in nitrogen with small admixture of hexamethyldisiloxane (HMDSO) was used for the deposition of thin organosilicon films. The thin films were deposited on glass, silicon and polycarbonate substrates, the substrate temperature during the deposition process was elevated up to values within the range 25 • C -150 • C in order to obtain hard SiO x -like thin films. The properties of the discharge were studied by means of optical emission spectroscopy and electrical measurements. The deposited films were characterised by Rutherford backscattering and elastic recoil detection methods, x-ray photoelectron spectroscopy, infrared spectroscopy measurements, ellipsometry and depth sensing indentation technique. It was found that the films properties depend significantly on substrate temperature at deposition. An increase of substrate temperature from 25 • C to 150 • C leads to an increase of film hardness from 0.4 GPa to 7 GPa and the film chemical composition changes from CH x Si y O z to SiO x H y . The films were transparent in visible range.

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Two dispersion models of disordered solids, one parameterizing density of states (PDOS) and the other parameterizing joint density of states (PJDOS), are presented. Using these models, not only the complex dielectric function of the materials, but also some information about their electronic structure can be obtained. The numerical integration is necessary in the PDOS model. If analytical expressions are required the presented PJDOS model is, for some materials, a suitable option still providing information about the electronic structure of the material. It is demonstrated that the PDOS model can be successfully applied to a wide variety of materials. In this paper, its application to diamond-like carbon (DLC), a-Si and SiO2-like materials are discussed in detail. Unlike the PDOS model, the presented PJDOS model represents a special case of parameterization that can be applied to limited types of materials, for example DLC, ultrananocrystalline diamond (UNCD) and SiO2-like.

The paper discusses the deposition of protective coatings ranging from organosilicon plasma polymers to SiO 2 -like films and hard diamond-like carbon/silicon oxide (DLC : SiO x ) coatings in radio frequency capacitively coupled discharges using hexamethyldisiloxane (HMDSO). As a result of the optimization of the deposition conditions it was possible to obtain high performance protective coatings. In the HMDSO/O 2 mixture, it was shown that rather than the SiO 2 -like film a hard cross-linked SiO x C y H z polymer film can be used as a protective coating for polycarbonate. The optimum conditions for the deposition of an almost stress-free film were 17% of HMDSO and dc bias voltage of −240 V. The film hardness and elastic modulus were 10 GPa and 75 GPa, respectively. The refractive index at 600 nm was 1.5 and the extinction coefficient decreased from 0.02 at 240 nm down to zero at 600 nm. The films deposited from HMDSO/CH 4 and HMDSO/CH 4 /H 2 mixtures exhibited the attractive properties of DLC films with the partial elimination of some of their drawbacks, such as absorption in the visible and a high intrinsic stress. The optimum concentration of the HMDSO was approximately 21%. Under these conditions the concentration of SiO x in the films was approximately 9 at.%. The film hardness and elastic modulus were above 22 GPa and 120 GPa, respectively.

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