Single layer antireflection coatings (SLAR) consisting of nanoporous silica (NP SiO 2 ) films are developed by selective chemical etching of atomic layer deposited (ALD) Al 2 O 3 :SiO 2 composite films. The reflective index of the final NP SiO 2 film is finely adjusted from 1.132 to 1.400 at 600 nm wavelength by applying an appropriate ratio in the composite. To meet the requirements of the SLAR coatings from the deep UV (DUV) to the near IR (NIR) spectral range, the film thickness is controlled with nanometer precision by the ALD process. The SLAR are simultaneously applied on both sides of flat or highly curved substrates. Transmittance values above 99.4% are achieved even at a wavelength of 193 nm on fused silica substrates. Various characterization methods demonstrate the advantages of these SLAR with regard to impurities, optical losses, laser induced damage threshold (LIDT) properties, and surface super-hydrophilicity. The absorption losses at 193 nm wavelength as determined by laser induced deflection measurements amount to approximately 200 ppm, and to approximately 2 ppm at a wavelength of 1064 nm, while the scattering losses are around 30 ppm at 532 nm wavelength for quarter-wave layers. The LIDT values at 1064 nm are in the range of 93 J cm À2 being close to the values measured on the uncoated substrate.
Tüket c satın alma davranışı; n ha tüket c n n yan k ş sel tüket m ç n mal ve h zmet satın alan hane halkı ya da b reyler n satın alma davranışıdır. Satın alma davranışı sosyal, kültürel, ps koloj k ve k ş sel faktörlerden etk lend ğ ç n, k ş ler homojen özell k göstermemekted rler. Bundan dolayı k ş den k ş ye değ ş p farklı satın alma eylemler ortaya çıkmaktadır. Bu çalışmanın ana amacı, tüket c ler n gıda ürünler satın alırken d kkat ett kler temel özell kler n bel rlenmes ne yönel kt r. Bununla b rl kte tüket c ler n gıda ürünler n lk kez satın alma kararı vermede etk l olan faktörler ve gıda ürünler satın alırken marka terc h nde göster len davranış şek ller n bel rlemek çalışmanın amaçları arasında yer almaktadır. Araştırma İzm r l merkez lçelerdek (
Antireflective coatings are widely applied on transparent optical components to reduce reflections at surfaces. Nanoporous silica (NP S i O 2 ) thin films with tailored refractive index properties are used as single-layer antireflective coatings providing nearly zero reflectivity. In this work, light scattering properties of nanoporous silica single-layer antireflective coatings are investigated in order to determine their optical quality by means of total scattering and detailed roughness analysis. Scattering and roughness characterization of the samples coated with different film thicknesses were realized to distinguish the influences of nanopores and surface roughness on scattering losses in the visible (VIS) spectral range. No significant correlation of scattering losses with the film thickness is found, showing negligible influence of the nanopores to the overall scattering properties compared with the dominating effect of interface roughness. Moreover, the scattering losses from coated fused silica glass were observed as low as 20 ppm (0.002%). It is confirmed that NP S i O 2 single-layer antireflective coatings are suitable to be used in optics demanding extremely low scattering characteristics.
Sub-aperture fabrication techniques such as diamond turning, ion beam figuring, and bonnet polishing are indispensable tools in today’s optical fabrication chain. Each of these tools addresses different figure and roughness imperfections corresponding to a broad spatial frequency range. Their individual effects, however, cannot be regarded as completely independent from each other due to the concurrent formation of form and finish errors, particularly in the mid-spatial frequency (MSF) region. Deterministic Zernike polynomials and statistical power spectral density (PSD) functions are often used to represent form and finish errors, respectively. Typically, both types of surface errors are treated separately when their impact on optical performance is considered: (i) wave aberrations caused by figure errors and (ii) stray light resulting from surface roughness. To fill the gap between deterministic and statistical descriptions, a generalized surface description is of great importance for bringing versatility to the entire optical fabrication chain by enabling easy and quick exchange of surface topography data between three disciplines: optical design, manufacturing, and characterization. In this work, we present a surface description by stitching the amplitude and unwrapped phase spectra of several surface topography measurements at different magnifications. An alternative representation of surface errors at different regimes is proposed, allowing us to bridge the gap between figure and finish as well as to describe the well-known MSF errors.
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