Optical Coatings

The descriptions of the new products listed in this section are based on information supplied to us by the manufacturers. Physics Today can assume no responsibility for their accuracy. For more information about a particular product, visit the website at the end of the product description.Plain bearingsSection:ChooseTop of pagePlain bearings <<Carbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometerThe LM76 plain bearings produced by LM-Tarbell employ advanced polytetrafluoroethylene polymers, ceramic, and specialty composites for linear and rotary applications to meet the requirements of motion-system designers. The bearings are chemically and mechanically resistant under harsh conditions. They are compliant with government standards and are suited for food processing and packaging, medical products, pharmaceuticals manufacturing, robotics, assembly and construction equipment, and marine applications. The company provides RC60, 300 series stainless steel, and ceramic-coated shafting and offers pillow blocks and flange blocks in aluminum, ceramic-coated aluminum, and stainless steel. The ceramic-coated series of plain bearings handles high-speed applications and loads up to 10 times faster than linear ball bushing bearings. Also available are custom-blended polymer bearings for extreme applications such as high heat. LM-Tarbell, 140 Industrial Drive, East Longmeadow, MA 01028, http://www.lm-tarbell.com Carbon nanotubes for AFM probesSection:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ... <<Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometer Carbon Design Innovations (CDI) makes atomic force microscope probes from carbon nanotubes. The CNTs offer a method of expanding the depth of profiling from the surface of the probe by several nm to µm. They feature higher resolution, a higher-aspect ratio, and longer lifetimes than typical AFM probes. The result can be a high-resolution image at a molecular and submolecular scale of structures which are several hundred nm to 1 µm deep. CDI’s carbon core high-resolution (CCHR) probes are used for general high-resolution imaging purposes. They are a bit shorter than high-aspect ratio probes, but they are reinforced at the base so they can extend down to about 200 nm. That enables the high-resolution imaging aspects of AFM to be applied to structures of more complicated materials. The CCHR probes’ primary focus application is on material characterization and metrology. Carbon Design Innovations, 1745 Adrian Road, Unit 20, Burlingame, CA 94010, http://www.carbondesigninnovations.com Aluminum coating for excimer lasers Section:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci... <<Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometer Excimer lasers operate only in the pulsed mode, so each exposure consists of numerous pulses. The projection optics typically experience fluences in the range of 0.1 mJ/cm2 to 1 mJ/cm2 per pulse. Some of the other optics in the system are subjected to fluences in the range of 1 mJ/cm2 to several mJ/cm2 per pulse. Since a production-line system might involve several million pulses per day, the optics must be able to withstand several billion pulses over their lifetimes. Saint-Gobain Crystals has introduced a high-reflectance aluminum coating for excimer laser-based scanning applications. The Alpine Research Optics–brand thin film is UV enhanced and delivers more than 95% reflectivity at 193 nm and an average reflectivity of more than 85% from 400 to 1000 nm. The metal/dielectric coating also delivers better than 90% reflectivity at 193 nm over an angle-of-incidence range of ±10°. The coating is supplied on various substrates suitable for galvanometer scanners, including rectangular fused silica with chamfered edges. Saint-Gobain Crystals, 6810 Winchester Circle, Boulder, CO 80301, http://www.saint-gobain-northamerica.com Barrier properties of PLA filmsSection:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA... <<Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometerSono-Tek offers a system to enhance barrier properties of polylactic acid films based on the company’s ultrasonic atomization spray coating line. The system applies an ultrathin layer of clay nanoparticles to compostable films and significantly enhances their barrier properties. It offers the packaging industry an efficient and cost-effective way to prolong the shelf life of compostable packaging films. Nano-particles have a tendency to agglomerate while being dispensed, which results in an uneven coating-layer thickness. Sono-Tek’s ultrasonic nozzles disperse those suspensions with high uniformity by imparting vibrations into the liquid suspension, thereby providing an agglomerate-free, uniform coating. The unpressurized spray cuts down on the amount of overspray, since droplets settle on the substrate rather than bouncing off; the technology reduces waste and generates 30%–60% cost savings. Sono-Tek Corporation, 2012 Route 9W, Milton, NY 12547, http://www.sono-tek.com Carbon nanotubes of improved puritySection:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro... <<Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometerGoodfellow Corp has made available economical, high-purity nanomaterials employing a technique used for carbon nanotube manufacture. The CNTs are developed by Sustainable Carbon NanoTechnology and Engineering in Ohio. Conventionally produced nano-materials include electrochemically active impurities from the catalysts used in their production. The manufacturing technique developed by SCNTE does not involve such catalysts, so the carbon nanomaterials are free from contaminants found in electrochemically active metals such as nickel and iron. The high purity of the materials, which makes inhouse preuse purification unnecessary, can help researchers use carbon nano-materials in their applications at competitive cost. Standard carbon nano-materials in the Goodfellow catalog include 50–100-nm nanoclusters, 1- and 2-µm clusters, whiskers with nominal dimensions of 200 nm by 20 µm, and Carbon Nanokit. Goodfellow Corporation, 305 High Tech Drive, Oakdale, PA 15071-3911, http://www.goodfellow.com Gas plasma system for powder treatment Section:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow... <<Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometerPlasmatech has added to its line of low pressure gas plasma systems the AL200-D for treating powder, pellet, and crystalline materials. A specially designed 5-L rotating chamber ensures treatment consistency, even when processing very fine powders and compounds. Production systems with larger chambers are available to accommodate higher-volume requirements.The AL200-D, which is clean room compatible, is available in a tabletop version or with a freestanding enclosure so users can incorporate a vacuum pump in the system cabinetry. To ensure process repeatability, the system is equipped with programmable logic control, recipe storage, error monitoring, and mass-flow controllers for precise gas measurement. Plasma generation via microwave frequency results in very low chamber temperatures, which eliminates the need for cumbersome, leak-prone liquid electrode cooling. Plasmatech Inc, 1895 Airport Exchange Boulevard, Suite 190, Erlanger, KY 41018, http://www.plasmatechnology.com Heated glass for outdoor cameras Section:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ... <<Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometerAbrisa has announced its new LuxVu heated optical windows for cameras and displays operating in rugged, wet, or cold outdoor environments; for imaging and sensing devices in the field, such as traffic, ground security, and unmanned aerial vehicle cameras; and for optical instrumentation panels on air and ground vehicles. The windows are made of transparent conductive coatings designed to keep the optical glass free from moisture and fog. The heated windows also aid in deicing in extreme weather conditions. They may be combined with various custom display enhancements and coatings. For example, antireflection coatings help protect the display while providing higher performance and improved transmission. Abrisa also offers additional glass fabrication and optical coating services for the heated optical windows. Customized solutions include screen printing, busbar, epoxy, glass strengthening, etching, and special masking. Abrisa, 200 South Hallock Drive, Santa Paula, CA 93060, http://www.abrisa.com Optical coatings on plasticsSection:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast... <<Laser drilling of wafer-b...Portable microviscometerDeposition Sciences Inc (DSI) has introduced optical thin-film coatings for plastic materials and substrates such as Ultem, Zeonex, and various polycarbonate plastics. The rugged, reliable coatings for plastic optics operate from the visible through the IR spectral wavelengths. Thin-film plastic coatings are suitable for applications for which lightweight and low-cost optics are specified, such as LED lighting, medical devices, unmanned aerial vehicle optics, and photovoltaic solar systems. The company’s optical thin-film coatings include bandpass filters, dichroic coatings, and high reflectors. DSI’s sputter deposition technology generates coatings on plastics, metals, and other thin-film materials and creates multilayer thin-film coatings for optics, MEMS, and other nanotechnologies. The company says its coatings will pass the stringent 24-hour humidity, adhesion, and moderate abrasion environmental tests. Deposition Sciences Inc, 3300 Coffey Lane, Santa Rosa, CA 95403, http://www.depsci.com Laser drilling of wafer-based solar cells Section:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b... <<Portable microviscometerThe Jenoptik lasers and material processing division has developed a laser processing technology for drilling minute through holes in wafers for solar cells. One of the crucial factors in the photovoltaic industry is the so-called grid parity, a comparison of the costs of generating electricity via solar energy versus conventional methods. Achieving grid parity requires either an increased level of efficiency or a reduction in production costs. The Jenoptik-Votan Solas 1800 laser system improves solar-cell electrical efficiency through the use of metal wrap through and emitter wrap through technologies. To increase the active surface area of the cells, in both technologies the contacts are laid from the front side to the rear side of the cell. Therefore, users can dispense with the contact fingers, currently used as standard, that cover parts of the active surface area. Lasers & Material Processing Division, Jenoptik Laser-diode GmbH, Goeschwitzer Strasse 29, D-07745 Jena, Germany, http://www.jenoptik.com Portable microviscometerSection:ChooseTop of pagePlain bearingsCarbon nanotubes for AFM ...Aluminum coating for exci...Barrier properties of PLA...Carbon nanotubes of impro...Gas plasma system for pow...Heated glass for outdoor ...Optical coatings on plast...Laser drilling of wafer-b...Portable microviscometer <<Petrolab’s MiniVis 445 can precisely determine dynamic and kinematic viscosity over a wide temperature range. Reflection sensors provide coverage for a wide range of applications; even samples as dark as used or heavy oil can be measured with high accuracy and repeatability. The viscometer includes a small sample volume and automatic sample feeding. The measuring chamber is a rugged glass tube that contains a metal ball. The sample is fed into the tube by the automated system or manually with a syringe. The temperature of the whole sample cell and of the sample introduction system is controlled by a thermoelectric (Peltier) system, which allows for quick determination of viscosity indices. After the ball accelerates to a constant velocity, its time of descent is measured with two reflection sensors. The MiniVis 445 repeats the procedure by rotating the sample cell and measuring in the opposite direction. Ametek Petrolab, 2001 North Indianwood Avenue, Broken Arrow, OK 74012, http://www.petrolab.com © 2009 American Institute of Physics.

application is shown for editing, analysing, optimising, designing technologies anddetermining the optical constants out of the (R,T) measurements. A dynamic arborescent structure of data(optical coatings) has been used, allowing a great flexibility in describing the optical coatings. The opticalcoatings of the arborescent structure are defined on the same thin layers (defined in root), the change of alayer being detected by all the optical coatings of the arborescent structure, containing that layer. The layersare seen by coatings by means of some groups (structures) oflayers and some scale factors, the groups beingthe elements that describe the coating. So, one can study an optical coating or parts of coating (e.g. opticalmonitoring) under different conditions.Keywords: optical coatings design1. INTRODUCTIONWhen one is designing an optical coating, a computer assisted programme for exploiting the newhardware and software facilities is a strong and indispensable tool. Such a programme must cover all theactivities implied in the designing and manufacturing of optical coatings. The Windows 3 1 application, alsocalled STRAT V5.1, written in Borland C 3.0 has been performed (

248 nm laser interaction studies on LaF3/MgF2 optical coatings by cross-sectional transmission electron microscopy

An interior broadbeam HID uplight and an upstream roadway luminaire were developed to demonstrate that optical coated luminaire components can improve the visual effectiveness and energy efficiency of a lighting system. Optical coated reflectors and flat lens covers were very effective in the development of new improved lighting techniques. The coatings reduce reflection and transmission losses, opening the door to new design options for improving lighting performance and saving energy.

Optical coatings have been deposited by pulse magnetron sputtering of the target materials silicon and aluminium using the reactive gases oxygen, nitrogen and fluorine. The measured refractive index and roughness of the SiO₂, Si₃N₄, Ta₂O₅ and Al₂O₃ films indicate the deposition of very dense and smooth films. Absorption of SiO₂ and Al₂O₃ films is low even at a wavelength of 193nm. The sputter deposited AlF₃ layers have low absorption until 150 nm but then show an absorption edge. Examples of multilayer include antireflective coatings for ophthalmic lenses and cut filters consisting of up to 150 &#955;/4 layers. These films were produced at a single stationary coating station without interruption of film deposition by changing the reactive gas during the plasma process. This process was also used for the deposition of rugate filters with apodisation function by continuous variation of the reactive gas composition during the deposition.

Increasingly demanding requirements are being placed on optical interference coatings and in many cases, accurate and reproducible depositions of large numbers of multiple layers are required to fit within the stringent demands of industry. In order to meet some of the more severe requirements, Cametoid Limited has carried out a program to develop inhomogeneous optical films. The objectives of the program were to derive the technical knowledge and capability to produce advanced optical coatings using the method of inhomogeneous films, both by design and refinement and by computer controlled production. This paper presents the technique used and results obtained.

Compared to the breathtaking evolution of new coating technologies in the semiconductor industry in the last few years, developments in the field of optical interference coatings have been extremely modest. Classical thermal evaporation methods are still by far the most widely used for the large scale production of optical coatings. "Automation: The Optical Coating Revolution", to quote a recent publication1, is just about now having its first impact in the industry. Apart from control of the layer thickness, any automatic system must cope with the control and reproducibility of an inherent nonideal film structure2,3.

One of the significant limiting factors in gravitational wave detectors is the Brownian noise associated with the optical coatings [1], which are required to form the highly-reflective laser mirrors. UWS has a unique range of capabilities being used to help develop novel coating technology that can address this challenge, targeted for aLIGO+ and beyond.

Within the scientific conception of the modern world, thin film optical coatings can be interpreted as one-dimensional photonic crystals. In general, they are composed of a sequence of single layers which consist of different transparent dielectrics with a thickness in the nanometer scale according to the operation wavelength range. The major function of these photonic structures is to adapt the properties of an optical surface to the needs of specific applications. By application of optical thin film coatings with optimized designs, the spectral characteristics of a surface can be modified to practically any required transfer function for a certain wavelength range. For example, the Fresnel reflection of a lens or a laser window can be suppressed for a broad wavelength range by depositing an antireflective coating containing only a few single layers. On the basis of a layer stack with alternating high- and low-refracting materials, high reflectance values up to 99.999% can be achieved for a certain laser wavelength. In addition to these basic functions, optical coatings can realize a broad variety of spectral filter characteristics according to even extremely sophisticated demands in modern precision optics and laser technology. Moreover, recent developments in optical thin film technology provide the means to combine selected optical properties with other features concerning, for instance, the thermal, mechanical or chemical stability of a surface. The latest progress in ophthalmic coatings even includes the integration of self-cleaning, photoactive or anti-fogging functions in antireflective coatings on glass.

Optical instrumentation used in space normally employs optical coatings. Future interplanetary space missions will be characterized by ever longer stays in environmental conditions where low energy protons represent one of the main types of radiation impacting the coating longevity and performance. To ensure the reliability of coated optics, environmental resistance tests should be accurately planned to be representative for a mission. To this end, the existing standards for coating tests and the test results interpretation have been constantly improved. In this study, we analyze the relevant standards of the European Space Agency (ESA) and of the Chinese Space Agency (CSA) for testing coated optics for interplanetary missions, and in particular for the missions at the Lagrange points. We focus in particular on the applicability of these standards and hence on their possible refinement when specifically implemented to the optical thin films and coatings. We proceed with the development of a methodology for reliable interpretation of the proton irradiation tests for the optical coatings for interplanetary missions, first briefly overviewing the existing tools which allow for space environment simulation and hence deriving the test conditions for the Lagrange points. Furthermore, we apply the approach to testing of aluminum oxide optical coatings for applications in the visible spectral range, concluding on the representativeness of the proposed approach and on possible refinement of the existing standards for coating tests when they are specifically developed for optical applications.

The first part of the paper presents the test techniques and the equipment used to make them, as well as the morphological characteristics of the tested parts and the properties of the materials that compose them. Also, there are presented briefly the results obtained after testing the resistance of several types of optical coatings are presented. The full description of the testing operations and acquiring experimental results will be described in a future paper. The authors used techniques found in the literature, but also standardized ones, comparing the mechanical behavior of frequently used materials (for example: MgF2, TiO2, Ta2O5 and SiO2), deposited on a glass substrate (BK7). The tested parts are flat surfaces, with a diameter of 25 mm, covered with anti-reflective layers for the visible range. In this paper, various methods for testing the strength of thin films for three types of optical coatings have been studied and developed. The three types of coatings tested had the following morphological characteristics: AR (anti-reflective) single layer, AR 4 layers and AR 6 layers. From the results obtained from the tests, it was concluded that the strength of the optical coatings differs depending on the test to which the sample is subjected. The most resistant types of optical abrasion coatings were single-layer coating and four-layer coating, followed by 6-layer coating.KeywordsOptical coatingsAnti-glare coatingsLayers strength

The exposure of optical interference coatings to low-fluence DUV-radiation reveals changes of thin layer properties due to interactions between radiation field and thin film structure. An experimental set up for irradiating antireflective as well a high reflective coatings with 193nm excimer laser was used in order to study permanent cumulative changes in optical coatings at fluences ranging from 20mJ/cm 2 with up to 240 10 6 laser pulses. The optical ex-situ monitoring of radiation induced modifications enabled the differentiation of coating specific and substrate inherent alteration effects. The identification of conditions as well as degradation processes during the exposure could be achieved for several types of DUV-coating materials. They were deposited with an ultra low loss evaporation process onto calcium fluoride and fused silica substrates. Fluoride coating included LaF 3 , Na 3 AlF 6 , MgF 2 , AlF 3 oxide coatings consisted of SiO 2 and Al 2 O 3 exclusively.

As low refractive index materials in visible wavelength SiO2, MgF2, and Na3AlF6 have been used in the optical thin film coatings. While MgF2 and Na3AlF6 films have lower refractive index than SiO2 films, their mechanical properties are not as good as SiO2 films. On the other hand, in the semiconductor industry fluorine-doped SiO2 (SiOxFy) films prepared by the CVD method have been developed as an inorganic low-dielectric constant material.[1] In this study, we fabricated SiOxFy films by ion beam assisted deposition (IBAD) to utilize them in the optical coatings as a low index material with a better mechanical property and investigated the optical, mechanical, chemical properties of SiOxFy films.

Photothermal techniques are widely used in thin film characterizations and are particularly useful in studying laser-induced damage in optical coatings. The specific applications include measuring weak absorption, characterizing thermal conductivity, detecting local defects, as well as monitoring laser-interaction dynamics and determining laser damage thresholds. In this paper we take an overview of the principle of photothermal techniques, the various detection methods, and the progress made during laser decade in applying these techniques to optical thin films. Further potential and limitations of the techniques will also be discussed, with emphasis on in-situ studies of laser-interaction with thin films and local defects.

The laser induced deflection (LID) technique for absolute absorption measurements is introduced. From the general principle, several concepts are derived for measurements in optical materials, coatings and fibers. Experimental results will cover nonlinear optical crystals, optical coatings and fiber Bragg gratings.