This PDF file contains the front matter associated with SPIE Proceedings Volume 6674, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

A dispersive method of white-light interferometry for measuring the tomographical thickness profile of a thin-film layer through a Fourier-transform analysis of a spectrally-resolved interference signal is proposed. The refractive index is also determined without prior knowledge of the geometrical thickness of the film layer. In contrast with standard white-light scanning interferometry, dispersive white-light interferometry generates the spectral distribution of interferograms directly by means of dispersive optics without mechanical depth scanning. Therefore, the proposed method in this paper is well suited for in-line 3-D inspection of dielectric thin-film layers, particularly for the semiconductor and flat-panel display industry, with high immunity to external vibration and high measurement speed.

Oblique angle deposition allows the fabrication of nano-structured porous thin films of high optical quality. By selecting the incident angle, the porosity - and thereby, the refractive index - of the deposited film can be tuned to a specific desired value. This makes it possible to fabricate multi-layer optical thin film components consisting entirely of a single material which is chosen for its properties other than refractive index, such as optical absorption or conductivity. As an application for this technique we demonstrate a conductive distributed Bragg reflector (DBR) designed for 460 nm. Common material choices in this wavelength range are SiO₂ and TiO₂; however, both materials are insulating. Conductive DBRs are limited to epitaxially grown doped semiconductors, which generally have low index contrast. The DBR reported here is composed entirely of indium tin oxide (ITO), chosen for its conductivity and low absorption. By varying the deposition angle a refractive index contrast of Δn = 0.4 is achieved, which yields a measured reflectivity of 72.7% for a three-period low-porosity-ITO/high-porosity-ITO DBR. The reflectivity is in excellent agreement with theory.

We report on the design and fabrication of metal-dielectric photonic band-gap structures (MDPBGs) with high transmission and broad spectral bandwidth in the visible range. Using the complex refractive index measured by spectroscopic ellipsometry, we have designed structures with an aperiodic thickness distribution which show a flat passband transmission (64% ± 1.5%) over more than 150 nm within the visible spectrum. Using e-beam deposition, we demonstrate the growth of continuous 12 nm Ag layers on Al₂O₃, and MDPBGs with five periods of Al₂O₃/Ag/Al₂O₃ that show more than 49% ± 2.5% transmission and at least 150 nm bandwidths. When compared to dielectric-dielectric stacks, the use of metallic layers provides excellent out-of-band rejection, in particular beyond the IR edge where the MDPBG acts collectively as a metallic solid. Such structures could thus be used as hot mirrors with extremely high and broad out-of-band rejection.

The triangle shape of two dimensional photonic crystals were fabricated based on autocloning technique, and preserved the periodic surface corrugation after the deposition of multilayer stacks using an E-beam gun evaporation with ion-assisted deposition (IAD). Drude model has been applied to analyze the effective refractive indices of the structural single-layer and multilayer autocloning films with triangle shape in the visible range which divided into several periodic parts. The advantage of using the model of effective refractive index is the optical properties of structural multilayer films can be analyzed easily. The effective refractive indices have been calculated based on this model, and simulated the reflectance and transmittance of the different incident angles. The influences of the structure period on the reflectance and transmittance were also analyzed.

Antireflection coatings have been fabricated by self-assembly using silica nanoparticles. The ionic self-assembled multilayer (ISAM) films are tightly packed and homogeneous. While the geometric properties of a matrix of spherical particles with corresponding void interstices are highly suitable to meet the conditions for minimal reflectivity, it is also a cause for the lack of cohesion within the constituent body, as well as to the substrate surface. This study investigates methods for improving the interconnectivity of the nanoparticle structure. One such method involves UV curing of diazo-resin (DAR)/silica nanoparticle films, thereby converting the ionic interaction into a stronger covalent bond. Factorial analysis and response surface methods are incorporated to determine factors that affect film properties, and to optimize their optical and adhesive capabilities. The second study looks at the adhesive strength of composite multilayer films. Films are fabricated with silica nanoparticles and poly(allylamine hydrochloride) (PAH), and dipped into aqueous solutions of PAH and poly(methacrylic acid, sodium salt) (PMA) to improve cohesion of silica nanoparticles in the matrix, as well as binding strength to the substrate surface. The results of the two studies are discussed.

Multilayer-dielectric (MLD) diffraction gratings are used in high-power laser systems to compress laser-energy pulses. The peak power deliverable on target for these short-pulse petawatt class systems is limited by the laser-damage resistance of the optical components in the system, especially the MLD gratings. Recent experiments in our laboratory have shown that vapor treatment of MLD gratings at room temperature with organosilanes such as hexamethyldisilazane (HMDS) produces an increase in their damage threshold at 1054 nm (10-ps, 370- μm spot size) as compared to uncoated MLD grating control samples. The 1-on-1 laser-damage threshold of an HMDS-treated grating increased by 4.5% as compared to the uncoated control sample, while the N-on-1 damage threshold of an MLD grating treated with tetramethyldisilazane increased by 16.5%. For an MLD grating treated with bis-(trifluoropropyl)tetramethyldisilazane, the N-on-1 and 1-on-1 damage thresholds increased by 4.8% and 5.3%, respectively. Such increases in laser-damage threshold are unprecedented and counterintuitive because it is widely believed that the presence of organic materials or coatings on the surfaces of optical substrates will inevitably lead to reduced laser-damage resistance.

The indium tin oxide (ITO) is one of the most popular transparent conductive oxide (TCO). The process of fabrication of ITO nanocrystallites has been described in our previous work. In present work the ITO layers were deposited on glass substrates by spin-coating method.. For some solutions ITO, SnO₂ and In₂O₃ nanocrystals were added. All those nanocrystals were synthesized by modified Pechini method. Optical and electrical properties of the layers were measured, compared and discussed.

Silicon based thin film alloys are deposited using plasma enhanced chemical vapor deposition (PECVD) with silane, ammonia, and nitrous oxide as precursors with different partial pressure ratios. Numerous deposition conditions have been considered to produce films with a wide range of refractive indices. The optical properties of the films are mostly affected by hydrogen content and stoichiometry, which are characterized by means of Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) respectively. The results of spectroscopic ellipsometry measurement of the refractive index are correlated with stoichiometry extracted using XPS to enable the prediction of optical properties from process conditions. Based on the film characterization results, a graded index film is deposited to minimize the reflection loss. The optical properties of the film to be used as anti-reflection coating (ARC), i.e. the transmittance and reflectance, are measured using an optical spectrophotometer. In spite of the optical absorption in the high refractive index part of the film, it is shown that by employing a very thin layer of amorphous silicon, it is possible to reduce reflection below conventional graded index films consisting of silicon oxynitride, and still maintain the transmittance required for solar cell applications.

Hydrogenated microcrystalline silicon (μc-Si:H ) thin films have attracted many attentions due to the high mobility compared with the amorphous silicon (a-Si) thin films. To fabricate μc-Si:H thin films, plasma-enhance chemical vapor deposition (PECVD) is the most popular method. The disadvantages of PECVD are the high facility cost and using the toxic processing gases such as silane (SiH₄). Whereas there is no these disadvantages using radio-frequency (RF) magnetron sputtering to deposit silicon thin films. Unfortunately, the silicon thin films deposited by the regular RF magnetron sputtering are a-Si. In this study, μc-Si:H thin films were fabricated using RF magnetron sputtering with argon and hydrogen as working gas at low substrate temperature (T_s=250°C and 350°C).The grain sizes, crystal volume fractions and photosensitivity (ratios of dark conductivities and photo conductivities) of the μc-Si:H thin films which deposited with different hydrogen partial pressures and sputtering powers were analyzed. The results showed that the grain sizes and the crystal volume fractions were increased and the photosensitivity was decreased as the hydrogen partial pressure increased at the sputtering power 200W. The grain size was between 15 to 20 nm and the crystal volume fractions was between 75 to 80% when the hydrogen partial pressure was over 90%.

Transition metal (TM) doped ZnO is a promising diluted magnetic semiconductor (DMS) material for the fabrication of spintronics devices. In this paper, we have investigated Mn and Cr doped ZnO thin films grown by RF magnetron sputtering. The films grown on Si(100) and sapphire (Al₂O₃) have been characterized by X-ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM) to know its structural and magnetic properties. The XRD results show that the Mn doped ZnO films deposited on Si (100) exhibit a polycrystalline nature whereas the films on sapphire substrate have only (002) preferential orientations indicating that the films are single crystalline. It has been observed from VSM studies that Zn_1-xMn_xO/Al₂O₃(0001) and Zn_1-xCr_xO/Si(100) system shows ferromagnetic nature while the paramagnetic behaviour observed in Zn_1-xMn_xO/Si(100) system.