bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion Assisted Deposition (IAD) of YF3 Films on Ge and ZnSe Substrates
Authors: Essex Douglas M. , Guenther Karl H.
Published: February 2023

Increasing regulatory and environmental concerns trigger a growing demand for replacing ThF4 with a non-radioactive, low-index infrared (IR) coating material with (at least the same) good evaporation characteristics and durabilty of the deposited films. Naturally, many other fluorides have been investigated1,2,3 for their suitability as a ThF4 substitute, and YF3 has been purported commercially as a good candidate.4 Unfortunately, its thermal expansion coefficient does not match well other common IR materials, so that the substrate temperature during deposition is normally kept below 200 °C. Such low substrate temperature causes relatively porous films which adsorb water vapor both during and after deposition.5,6 The rather loose packing often causes these films to fail severe abrasion tests commonly required for IR coatings.
A Physical Vapor Deposition System for Omega Upgrade Optics
Authors: Carnes Rex G. , Smith Douglas J.
Published: February 2023

The plans for the OMEGA Upgrade Project include over 2000 additional optical components, including over 60 polarizers for use at 1054 nm and 120 mirrors at 351 nm over a range of angles including 9° and 60° incidence as upper and lower extremes. A large number of these optics are to have a major dimension of 27 in. Plans are being made to coat up to three of these largest optics at once in a planetary system.
Improvements in mirror quality of reflective spatial light modulators using dielectric coatings and mechanical polishing
Authors: O’Hara A. , Hannah J.R. , Holwill R.J. , Underwood I. , Vass D. G.
Published: February 2023

The objective of this work is to improve the optical performance of mirrors on silicon backplane spatial light modulators (SLM). Currently this is done in two stages. The first improvement is achieved through the deposition of a protective coating applied at an appropriate stage in the microfabrication process sequence. Further enhancement is achieved by adding a novel processing stage involving wafer polishing.
Development of Iad Technique in China
Authors: Xing-Yi Chen
Published: February 2023

Many research results show that Ion-Assisted Deposition technique has good result in the improvement of film character, film microstructure, stress state and surface state. Many films with new function can be got. Since the IAD technique was used, many specialists and engineers in China have been specializing in the IAD technique. They not only developed IAD technique, but also manufactured the series of ion sources for IAD. A lot of work about IAD process is explained in this paper. The experimental parameters and results are also listed.
Monitoring Optical Thickness Of Infrared Coatings During Deposition
Authors: Zhang Keqi , Zhang Fengshan , Yan Yixun
Published: February 2023

Manufacturing optical interference coating in infrared region is similar to that in visible but more strict deposition process must be followed. Because of the special problems in infrared region like low signal to noise ratio, more and thicker layers in coating design and lack of usable coating materials, there are still some problems in the deposition process. In this paper, our discussion will be focused on the optical thickness monitoring during coating deposition.
Multichannel Real Time in Situ Spectroscopic Ellipsometry used for Monitoring of Process Control
Authors: Piel J.P. , Stehle J.L. , Thomas O. , Zalczer G.
Published: February 2023

Spectroscopic Ellipsometry is widely used to characterize optical thin multilayers films in a broad spectral range, from UV 250 nm to NIR 1.7 μm. Recently the use of optical multichannel array, OMA, as detector has reduced drastically the time of measure for a spectrum versus a simplex PMT detector ( ref 1 ). This enables to scan the angle of incidence or the surface mapping of the sample rapidly for homogeneity characterization of layers particularly useful for F.P.D. on line control. But this characterization comes too late and does not enable to correct the process of deposition in real time. In order to monitor in situ a growth or deposition of layers, single wavelength ellipsometers have been used (ref 2), also PEM spectroscopic ellipsometry have been utilized for very fast deposition, with less accuracy. One wavelength is not enough to get advantage of the full spectral range analysis, and of the spectral dispersion from UV to IR at same time.
Emission Spectroscopy of Reactive Low Voltage Ion Plating for the Deposition of Metal-Oxide Thin Films
Authors: Zarrabian S. , Lee C. , Guenther K. H.
Published: February 2023

Reactive Low-Voltage Ion Plating (RLVIP) is increasingly used as the method of choice for the production of dense, environmentally stable optical coatings.1 The operational details of this process, including system geometry, plasma voltages and currents have been published elsewhere.2,3 As with other plasma based methods, understanding the exact physics and chemistry of this complex process requires a very thorough and detailed analysis. One of the most important questions in the application of this process for the deposition of refractory oxide coatings is the nature and the role of the main oxidizing agent.
Characterization by guided wave of instabilities of optical coatings submitted to high power flux : thermal and third-order non-linear properties of dielectric thin films
Authors: Flory F. , Rigneault H. , Maythaveekulchai N. , Zamkotsian F.
Published: February 2023

It is now well known that generally dielectric thin films behave very differently from bulk materials. They can exhibit unstable optical properties due to water adsorption-desorption phenomena. When lightened with a high power flux they can have damage threshold much lower than the bulk; but, before damage occurs, their optical properties can be unstable in a reversible way. Both thermal and non linear effects can give such reversible instabilities.
Comparison of elemental composition and optical absorption of high damage threshold oxide coatings deposited by reactive electron beam evaporation and reactive low voltage ion plating
Authors: Guenther K. H. , Balasubramanian K. , Hu X.-Q. , Baumann S. M. , Edgell M. , Chow R. , Rainer F. , Stolz C.
Published: February 2023

Reactive low voltage ion plating (RLVIP) produces dielectric thin films of excellent quality with dense, glassy microstructure and smooth surface, thus featuring low bulk and surface light scattering. The dense structure also prevents moisture penetration and consequential spectral shift of transmission or reflectance characteristics. Hence, these films seem to be well suited for laser applications. However, earlier results showed a somewhat disappointing laser induced damage threshold (LIDT), lower than that of electron beam deposited thin films of the same material. This investigation aims at a better understanding of the underlying mechanism for the lower LIDT in RLVIP thin films and tries to identify effects introduced by chemical composition (suspected small sub-stoichiometry) or localized growth defects (perhaps sub-micron-size metal or sub-oxide clusters).
Studies on Infrared Absorption Loss of Antireflection Coatings on Germanium and Potassium Chloride Substrates at the Wavelength of 10.6μm by Photothermal Deflection Technique
Authors: Liu Xu , Atanassov Georgi , Gu Pei-fu , Sao Qin , Tang Jin-fa
Published: February 2023

In order to develop optical coating devices for high power laser systems, it is necessary to have coatings with ultra low absorption loss, high laser damage threshold and good mechanical adhersion properties. Ion assisted deposition (IAD) is known to produce thin films with characteristics that the conventional thermal evaporation techniques can not realise[1], and meets the needs of this.
Experimental Determination of Optical Properties by Using two Characteristic Isoreflectance Angles
Authors: Machorro R. , Siqueiros J. , Regalado L.E.
Published: February 2023

Many of the problems found when growing optical thin films to produce a designed multilayer stack, are related to the monitoring of the physical thickness, which in general, requires the mass density of the material as input data.
Determination of the Optical Constants of Molecular Beam Deposited Thin Films
Authors: Meredith Paul , Buller Gerald S. , Walker Andrew C. , Smith S. Desmond
Published: February 2023

The wide application of optical multilayer interference coatings has prompted the "growth" of numerous new vacuum and non vacuum techniques [1]. One such approach is that of Molecular Beam Deposition (MBD). A molecular beam epitaxy system, in our case an adapted VG Semicon V90H kit, is used under ultra high vacuum conditions for the production of polycrystalline films deposited on optically transparent substrates. Applications include, high damage threshold laser coatings [2], and also the fabrication of high finesse nonlinear Fabry Perot interference filters (NLIF) for use as logic, memory or threshold devices in the field of digital optical computing [3].
A Method for Determining Dielectric Losses of Thin Films
Authors: Lalezari R. , Kriewaldt M. , Long D.
Published: February 2023

Changes in the reflectivity of ultra low loss mirrors, after overcoating with evaporated dielectric films, can be used to determine the losses of those films.
Indices and Thicknesses Determination of Thin Optical Multilayer Coatings by Spectroscopic Ellipsometry
Authors: Neumann W. , Piel J.Ph. , Stehle J.L.
Published: February 2023

Thin optical multilayer coatings, digital mirrors, have been measured by visible spectroscopic ellipsometry. Data reduction and limitations of results of this technics will be analyzed.
Variable Angle Spectroscopic Ellipsometer Fourier Transform Infrared, Description and Applications
Authors: Piel J.P. , Stehle J.L. , Thomas O.
Published: February 2023

Spectroscopic Ellipsometry (SE), has been used for several years to measure the thicknesses and refractive indices of optical multilayers (ref 1). The spectral range of SE, which starts in the UV with PMT, has been extended to 1.7μ by the use of NIR detectors. In the mid IR, 2 to 16μm, where atmospheric windows exist, most thin film coating measurements are made by spectrophotometry.
Antireflection coatings on KCl single crystal windows with low optical loss
Authors: Atanassov Georgi , Gu Pei-fu , Liu Xu , Tang Jin-fa
Published: February 2023

The most successful optical components for high power laser are those
which most constructively deal with the problem of absorption of laser
radiation and removed of waste heat to protect them from distortion
and even damage.
Spectral performance of cooled infrared filters
Authors: Weiting Feng , Yixun Yan , Cuiyuan Zhu
Published: February 2023

In this paper experimental results on mild PbTe material and vacuum deposited multilayers are reported. Optical absorption of mild PbTe is determined by envelope methods and found to be different from that of stoichiometric PbTe on cooling. Generally the performance of multilayer coatings which are composed of mild PbTe/ZnSe is deteriorated in middle infrared band when temperature decreases. The wavelength shift of a multilayer filter is essentially a linear function of filter temperature.
The Application of Molecular Beam Deposition for the Production of Nonlinear Interference Filter Optical Logic Elements
Authors: Meredith Paul , Buller Gerald S. , Walker Andrew C. , Smith S. Desmond , Muirhead Ian T. , Fisher Shari Powell , Leonard John F. , Orr Jim L.
Published: February 2023

Optically bistable nonlinear interference filter (NLEF) structures have been used as logic, memory or threshold devices in the field of digital optical computing. They operate via a temperature dependent refractive index change of the spacer [1]. Materials such as ZnSe and ZnS are commonly used as the nonlinear medium because of the magnitude of their dn/dT (~1x10-4K-1), and their ease of deposition [2]. Optical and thermal characteristics of such a device are critical factors if acceptable operating conditions are to be achieved [3,4]. For any parallel processing to be demonstrated large arrays of 2-dimensional binary data channels in the form of spatially separated pixels must be operated simultaneously on the device plane, so necessitating both high degrees of uniformity, and also low levels of cross talk [5]. A specific application demanding these properties is as the logic plane within a currently operating demonstrator; the Optical Cellular Logic Image Proccessor (O-CLIP) [6].
Reducing the Standing-wave Field Profile within High Reflection Interference Coatings
Authors: Johnson Walter E. , Crane Robert L.
Published: February 2023

Research to identify methods for increasing the laser damage threshold probability of high reflection interference coatings dates to the early 1970's. Particular emphasis has been placed on the wavelength(s) coinciding with the laser line(s) being reflected by these coatings. This work typically addressed multi-layer stack coatings. Our work has examined a sine-wave refractive index profile, commonly called a rugate filter (Ref 1). A single sine-wave refractive index profile having numerous identical cycles produces one well defined reflection band. This reflection band can be spectrally tailored and positioned anywhere within the passband of the filter with no associated higher order reflection bands present. The spectral location of this reflection band is twice the optical thickness of one of the cycles comprising the sine-wave refractive index profile.
The Fabrication of Optical Devices by Molecular Beam Deposition Technology
Authors: Fisher S.P. , Leonard J.F. , Muirhead I.T. , Buller G. , Meredith P.
Published: February 2023

Molecular beam deposition (MBD) technology has been used to fabricate complex optical devices of varying designs for diverse applications. This was achieved using a V90H system purchased by Heriot-Watt University with funding from the Science and Engineering Research Council and adapted by Optical Coatings, Ltd. to produce optical thin film structures. The major modifications included the addition of quartz crystal monitoring, broadband optical monitoring, and automated process control with data logging capability and built upon the research begun at the Royal Signal and Radar Establishment.1
Vacuum Deposited Thermal Control Coatings For Space Applications
Authors: Fisher Donald S. , Jafolla James C.
Published: February 2023

Coatings for controlling the temperature of satellites reguire a predetermined ratio of solar absorbtance α, to thermal emittance ε, to balance the absorbed solar energy with the thermal radiant energy emitted by the surface at the desired temperature. Specifically developed white paints, referred to as optical solar reflectors, OSRs, typically have low α and high ε, and are used for this purpose. Transparent polymers such as Mylar® and Kapton® with vapor-deposited metals of Ag, Au, and Al coated on the rear surface are also used, however, this treatment and the white paints degrade considerably in the space environment1. Evaporated films of aluminum and silicon oxide have been shown to produce a range of α/ε values and remain quite stable in space environments2.
Durable Low-Emissivity Solar Control Film
Authors: Wolfe Jesse , Thomas Bernard
Published: February 2023

Further conservation of energy continues to be a major priority, even with the advances that have been made in reducing our present consumption. For while energy use has gone down, costs continue to grow. Homeowners continue to look for ways to keep their fuel costs down. Buyers of new homes expect new construction to feature the latest in energy-efficient products such as insulated windows. Many insulated glass units (IGU's) have a thin film coating on one or two of the inner surfaces (#2 and #3) of the unit. Figure 1 illustrates such a unit.
High Reflectance Environmentally Protected Silver-based Mirrors Produced by Ion Assisted Deposition.
Authors: Sainty Wayne G.
Published: February 2023

This project was initiated to meet the optical coating needs of the Sydney University Chatterton Astronomy Department. The university is engaged in producing a very high angular resolution stellar interferometer (SUSI)1. The instrument involves eleven coelostats located in a configuration of minimum redundancy along a 640 metres baseline. Each coelostat is equipped with five 200mm diameter mirrors. In all there are fifty seven 200mm mirrors forming the beam line with ten in use at any one time. In the laboratory the starlight passes through a beam reducing telescope to be followed by an optical path length compensator which involves a further thirty two 80mm diameter mirrors. The starlight entering each coelostat will undergo as many as twenty three reflections before recombination at the optical tables.
Optical Properties of Metal Oxide Coatings Deposited Using Reactive Sputtering
Authors: Edlou Samad M. , Smajkiewicz Ali , Al-Jumaily Ghanim A.
Published: February 2023

Refractory metal oxide coatings are widely used for optical interference applications. These materials, used for bandpass interference filters, beamsplitters, anti-reflection coatings and protective coatings, are very hard and have a wide transmission range which extends from the UV to mid-IR. The materials included in this work cover a large index of refraction range.
Optimized Design of Antireflection Coating for Textured Silicon Solar Cells
Authors: Chiao Shu-Chung , Zhou Jiu-Lin , Macleod H.A.
Published: February 2023

The short-circuit density of solar cell is used as the merit function to optimize the solar cell AR coating designs. The Jsc/Jmax ratios reach 99% even with 20 nm thick passivation layer.
Polishing diamond films for optical applications
Authors: Hickey C. F. , Snail K. A.
Published: February 2023

Recent results using the hot iron thermochemical technique for polishing diamond films are presented, along with comparison to other polishing techniques.
Novel Lighting Industry Coating Applications
Authors: Lemons Thomas M.
Published: February 2023

Coated reflectors, lenses and lamps used in lighting systems are a growth market. Their cost is justified by achieving energy conservation, increased performance and system variability.
High Throughput Laser Line Polarizing Beamsplitters Using Rugate Coatings
Authors: Johnson W. E. , Southwell W. H. , Hall R. L.
Published: February 2023

Conventional polarizing beamsplitters constitute two right angle prisms, one having a multi-layer coating on the hypotenuse face, cemented together forming a cubic optical element. This paper presents two design methodologies for embedding a rugate coating into a polarizing beamsplitter. The function of the rugate coating is to be highly transmitting for both p- and s-polarized light except for a s-polarization reflection band at a specific wavelength. For convenience absorption, the optical cement, and all external faces of the polarizing beamsplitter are excluded from consideration.
Fourier transform method with refinement in the frequency domain for optical thin film design
Authors: Verly P.G.
Published: February 2023

Inhomogeneous optical coatings have received a lot of attention in recent years. Not only do they have unique physical properties, but they have also been found useful as an intermediate stage in the design of conventional multilayers.
Wide Angle Antireflection Coatings For IR Windows
Authors: Fisher Donald S.
Published: February 2023

Infrared (IR) transmitting windows and domes require antireflection (AR) coatings to reduce fresnel losses. The need for AR coatings effective at higher angles of incidence is more pronounced in the infrared than in the visible. This is due to the higher index of infrared substrate materials. A comprehensive review on AR coatings for IR materials has been written by Savage but examines broadband normal incidence coatings only1. The goal was to design improved antireflection coatings with particular attention to high angles of incidence, and without the use of radioactive materials.
Evaluation of Chracteristic of Optical Thin Film By Neural Network System
Authors: Ma Yuan-sheng , Liu Xu , Gu Pei-fu , Li Hai-feng , Tang Jing-fa
Published: February 2023

Controlling and mastering the optical constant of thin film is a key factor concern for the optical coating. Each optical constant must be controlled very well to make the films meet requires desired. At present, there are many methods to characterize the optical constants of the films, for example: the envelop method, ellipsometry measurement, waveguide prism methode etc.[1]. All of them use numerical inversion technique to obtain the optical constants from the physical parameters measured. These methods are very well for treating their problems, but they have their main shortages of indefinite and very complex. We propose now an artifical neural network (ANN) model to simulate the relationship between the spectral character and optical constant of the thin films. ANN is a simplified mathematical model of biological network, it is extremely strong in dealing fuzzy and indefinite problem, and is widely used for the signal process and recgonization. Neural networks have the ability to learn directly from example data rather than following programmed rules based on a knowledge base, and can treat the problem extremely fast and tolerate data containg experimental error[2].
Optimum Solutions to Single-Band Normal Incidence Antireflection Coating Problems
Authors: Tikhonravov A.V. , Trubetskov M.K. , Dobrowolski J.A. , Sullivan Brian T.
Published: February 2023

Antireflection coatings have been the subject of two books and of numerous scientific and technical papers.1,2 until recently, there have been no systematic studies made to determine the optimum performance that can be achieved for a given set of specifications and coating materials. Willey has published two papers with empirical studies of this problem.3,4 He has presented equations which, for a given set of coating materials and for an overall thickness of the multilayers, give an estimate of the lowest achievable reflectance for a normal incidence antireflection. The two equations presented by Willey are valid for a certain range of coating materials, widths of the spectral region and overall thicknesses of the multilayer. They are based on the calculated results obtained for a number of different examples . It will be shown in this paper that, whilst giving a good first estimate of the attainable results, the formulae are not accurate for any one set of coating materials.
Synthesis method for visible and infrared broadband spaceflight anti reflection coatings
Authors: Cole C. , Bowen J. W.
Published: February 2023

Broadband antireflection coatings are indispensable for spaceflight refractive optics, suppressing the ghosting of images and increasing the throughput of the optical elements. These coatings are required to be resistant to abrasion and radiation exposure, while operating over a bandwidth of typically 2 or 3 orders. The range of available thin-film materials is therefore restricted for these coatings and so any optimization routine is likewise restricted in its search for an optimal design. Existing refining or synthesis methods1 modify multilayer antireflection coating designs to an extent, but there is still no guarantee that the final design is the best which can be achieved for the given design parameters. Choosing the coating starting design, thin film materials, optimization routine and target function is of paramount importance in achieving the coating with the best performance. A synthesis routine for a computer is therefore outlined which will achieve optimal broadband antireflection coatings for spaceflight use by a judicious choice of starting design and a powerful optimization routine.
Intrinsic Stress in Mixtures of Fluoride Thin Films
Authors: McEldowney Scott , Brown Lindsey
Published: February 2023

In the construction of thin film interference filters, It is necessary to have materials with various indices of refraction. Thorium fluoride (ThF4) is an excellent material for use from the near ultraviolet to the far infrared spectral range. It has a low index of refraction, moderate stress in thin film form (20kpsi)(1), and it is environmentally very robust. The primary disadvantage of using ThF4 is its radioactivity.
Surface plasmon resonance probing of dynamic biomembrane processes
Authors: Salamon Z , Tollin G , Wang Y , Macleod H A , Zhao T
Published: February 2023

When the hypotenuse of a dielectric prism coated with the correct thickness of a suitable metal is illuminated with p-polarized light at the appropriate angle of incidence beyond critical the light couples into a bound surface wave on the outer surface of the metal. The coupling is marked by a sudden sharp and deep dip in the internal p-reflectance of the prism. This phenomenon is known as Surface Plasmon Resonance and this particular form of coupling is known as the Kretschmann [ 1 ] configuration. The resonance is a very sensitive function of the surface conditions and changes in its angular position and shape can be used as a probe of surface conditions. In particular it may be, and has been [ 2 ], used to track changes in a thin film deposited over the metal surface. The better the optical performance of the metal, the narrower is the resonance. The work reported here uses silver. Silver has very high optical performance and gives excellent resonance curves but suffers from long term durability problems.
Investigation of the phase composition for TiO2-SiO2 composite films prepared by reactive ion-assisted coevaporation using atomic force microscopy
Authors: Tsai Rung-Ywan , Ho F. C. , Hua Mu-Yi
Published: February 2023

Recently there has been a great deal of interest in studying TiO2-SiO2 composite films. These films can be produced by coevaporation,1 cosputtering,2 and sol-gel3 methods. Material studies have highlighted the novel properties of this composite films. From the x-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses, structures of TiO2-SiO2 composite and their compositional component films deposited by reactive ion-assisted coevaporation (IAC) are completely amorphous, which is one of the favored properties for optical coating materials. However, it is difficult to identify whether the structure of the composite films is a mixture of their component phases or a solid solution, because their diffraction patterns are too close to be distinguished. It has been shown that the atomic force microscope (AFM) can be used for measuring not only the topography, but the lateral friction force. With the measurements of lateral friction forces, it is useful in detecting the different phases on a nanometer scale. The aim of this paper is to study the phase composition of TiO2-SiO2 composite films prepared by reactive IAC using AFM. In combination with the results of XRD and TEM analyses, it is possible to distinguish that the structure of the composite film is a mixture of their component phases or a solid solution. The surface roughness of these films is also presented.
Extending a reststrahlen band with a dielectric coating
Authors: Andersson Stefan K. , Ribbing Carl G. , Staaf Örjan
Published: February 2023

We shall consider solutions for two related problems concerning thermal
emission: frost-prevention on electrical insulators and thermal
signature reduction of radomes. The optical requirement is low thermal
emittance in the atmospheric window 8-13 μm. The objects to protect
can be large and have a complex shape, which are strong argument
against advanced multilayer solutions. Corrosive and abrasive
resistance are important considerations as in many other optical
applications. A few years ago, beryllium oxide was identified as a
material for which the bulk optical emittance
has a spectral profile that is favourable for frost
prevention1.
Infrared Ellipsometry Investigations of SiOxNy Thin Films on Silicon
Authors: Brunet-Bruneau A. , Vuye G. , Frigerio J.M , Abelès F. , Rivory J. , Berger M. , Chaton P.
Published: February 2023

Silicon oxynitrides are extensively studied, because they are attractive for diverse applications in microelectronics or because of their low absorption in the near infrared. The change of their optical constants with composition makes these materials suitable for the production of graded index films. IR studies have been done in many cases by reflectivity R or transmittance T measurements, the optical constants being then calculated by using the Kramers-Kronig relation; p-polarized T measurements were also analyzed by a sum of classical oscillators[1]. A detailed study has on the other hand been done from R and T measurements on different types of substrates[2]. Very recently, high resolution electron-energy-loss-spectroscopy was used[3] to determine the function
Im(1/ε˜) which was fitted with a simple three-oscillator model after subtraction of a phenomenological background.
Studies of optical properties of hafnia and co-evaporated hafnia:magnesium fluoride thin films prepared by ion-assisted physical vapor deposition
Authors: Tsou Y. , Ho F. C.
Published: February 2023

There has been great interest in composite thin film materials in order to relieve the material constraints on refractive indices as well as to reduce the number of layers required in coating design (1, 2). We chose to study composite films of hafnia (HfO2) and magnesium fluoride (MgF2) because HfO2 is known to be a hard and durable high-index material in the near ultra-violet (near-UV) region while MgF2 has wide transmission spectral range extended into vacuum UV region in addition to being a highly durable low-index material (3, 4). We investigated composite films of various HfO2 and MgF2 compositions in search of a mixture which has better transparency in the UV region and relatively high refractive indices in the UV and visible spectral region.
Short Wave IR Multi-Spectrum Micro—Filters Array
Authors: Cheng Shiping , Yan Yi Xun , Zhang Fengshan
Published: February 2023

The focal plane chromatic dispersal element is a kind of new
micro-spatial filter which has being developed in the past few years,
Combining it with the detectors array the spectrum distinguishable
detectors array can be constructed. Use this new type of detector we
can simplify the structure of the spectrum splitting set-up, promote
its stability and reliability, as well as improve the optical
efficiency and signal to noise ratio of the instrument[1-2]. The focal
plane filters matched for the detectors array are principally the
micro-linear wedge filter and the micro-filters array, The wedge
filter, when matched for the detectors array, can provide more
spectrum channels, but its spectral properties and the total channel
number are proscribed by the dispersal theory of the gradient
structure of the filter[3-4]. compare with the wedge filter, the
micro-filters array has better band pass characters and more accurate
wave length location, and the available spectral channel number is
limited by the fabrication technique. In the application of few
channels is considered, the multi-spectrum detectors array with the
micro-filters array being the chromatic element is of some practical
value. So in this paper the design and preparation of the
micro-filters array for the multi-channeled IR humiditymeter is
reported.
8-14 µ IR Linear Variable Filter And The HgCdTe Array Detector Device With LVFs
Authors: Zhang Fengshan , Pan Jiandong , Xu Guosen , Yan Yixun
Published: February 2023

The development and application of IR focal plane array detector
accelerate the study of IR multichannel dispersion devices. IR
miniature linear variable filters (LVFs) are important dispersion
component which has been developing in recent years. [1-2] The
assembly, which is made up of miniature IR LVFs and HgCdTe array
detector, is a new type of IR array detective devices. Using the
device can simplify the optical system of multi-spectroscope detective
instruments, enhance the reliability and stability of multi-element
array detective instruments, and can minify the detective instruments
which will be made easy to be carry about. The more important point is
that it can differentiate different spectrum radiation, can detect
multi-spectra radiation speedily and simultaneously. It has very
important affect in the study of space, oceans and land objects and
research of background radiation. This paper consists three parts: the
design and deposition of 8-14µ miniature IR LVFs; the method of
assemble the miniature IR LVFs with miniature HgCdTe array detector;
and the method of measure the optical spectra property of the
assembled device.
Optical Coatings for Deuterium Fluoride (DF) Chemical Laser System
Authors: Xiong Shengming , Zhang Yundong
Published: February 2023

Deuterium fluoride laser system brings an interesting challenge to the development of optical coatings. A wide variety of different specifications, often contraditory, has to be fullfilled. The choice of deposition process and coating materials is critical with respect to losses, damage threshold, optical specifications, their long term stability and other optical properties.
Comparison of Fabrication Processes for Thin-Film Monolithic Electrochromic Devices
Authors: Mathew J G H , Hichwa B P , O’Brien N A , Raksha V P , Sapers S , Sullivan S , Wang L S
Published: February 2023

Interest in the use of electrochromic (EC) technology has been steadily growing in recent years(1). Applications include architectural and automotive glazings for glare and energy management and automated attenuators and filtering for instrumentaion.
Experimental Study of Low-Voltage -Driven Thin Film Electroluminescence Mechanism
Authors: Jia-yu Zhang , Fu Gu Pei , Xu Liu , Fa Tang Jing
Published: February 2023

Thin film electroluminescent devices are now attracting much attention since they have open up a way to the application to the flat panel display. However, the bases of the physical phenomena governing the electroluminescence have been reported comparatively little. This is due to the difficulties to treat in detail the carrier dynamics of the interface and the bulk in the high electric field (1). In this paper, we study experimentally the field distribution in phosphor layer and the properties of insulator/phosphor interface.
Low–Voltage–Driven Thin Film Electroluminescent Device with Stacked Insulators
Authors: Jia-yu Zhang , Pei-fu Gu , Xu Liu , Jing-fa Tang
Published: February 2023

The phenomenon of electroluminescence is the non-thermal conversion of electrical energy into luminous energy, in which the light is generated by impact excitation of a light emitting center by high energy electrons. AC driven thin film electroluminescant(AC-TFEL) devices are very attractive for use as flat panal display because they have a number of advantages, such as high brightness, high resolution, low power dissipation, complete solid-state multicolor flat-panel display ,and potential for use in large area. However, these devices need a high driving voltage of about 200V. This makes it difficult to use a compact driving circuit composed of available ICs, and as a result, lowering the driving voltage is one of the main keys to fabricate practical TFEL displays (1).
Coating of Fabry Perot Etalons
Authors: Netterfield R P , Sainty W G , Drage D J , Freund C H
Published: February 2023

There has been a resurgence of interest in the use of Fabry Perots as the narrow band selecting element in high-resolution imaging astronomical spectrometers. The trend has been to solid etalons1 and away from air-spaced interferometers which often require complex electronics to control parallelism and spacing of the flat plates. These may be manufactured from optically passive material such as silica where tuning is achieved by tilting or electrooptic material such as lithium niobate (LiNbO3) where the filter can be scanned electrically2. Typically the solid etalon has a thickness in the range 0.2-0.5 mm and a diameter in the range 40-70 mm. In this presentation we report on the role that coatings have played in the manufacture of a number of etalons. During the preparation of the substrate, departures from optical thickness uniformity over the aperture have been reduced by depositing layers with the same refractive index as the substrate to selected parts of the surface. Single wavelength and broad band high reflectance coatings have been applied to the surfaces of the etalons. In the case of the electrically tunable etalons, the outside layer of the coatings has consisted of a transparent conducting layer of indium tin oxide (ITO). Ion assisted deposition has been used to prepare hard, dense dielectric oxides layers as well as the ITO. No substrate heating has therefore been required. Measured finesses over the full working aperture have ranged from 15 to 30.
Application of Residual Stress Analysis for Ion-Assist-Deposited (IAD) Thin-Films Manufactured Using a Gridless End-Hall Ion Source
Authors: Fulton Michael L. , Kai Fu Ji , Hock Tan Fong
Published: February 2023

The residual stress of Titanium dioxide (TiO2) and Silicon dioxide (SiO2) films on Silicon (Si) substrates prepared by Ion-Assisted-Deposition (IAD) were systematically investigated. The films were deposited using a Balzers 760 vacuum chamber equipped with a diffusion pump, substrate heaters, optical monitoring, crystal monitoring, and a gridless end-Hall ion source. Substrates were tooled in either a universal planetary drive with 6 planets (dia. 225 mm) or a rotating, umbrella shaped holder (dia. 800mm). A standard electron beam source was used to evaporate the TiO, TiO2, or Ti2O5 starting materials for the TiO2 films. The starting material for the SiO2 thin-films was SiO heated with a resistant source. The end-Hall source produces a broad beam (30° half angle) with relatively high ion current densities (0.3 to 0.5 mA/cm2) at 400mm source to substrate distance.1
Design and process considerations for infrared multilayer notch filters
Authors: Kalem S.
Published: February 2023

Narrow bandpass (notch) filters are very important elements in eliminating the noise in optoelectronic devices. In many applications, the notch filters should be able to stop the wavelength of interest very precisely. Also, their characteristics are expected to be intact against the environmental changes. Furthermore, the operation of sensitive electronics should not be disturbed by the presence of these filters. There are different types of notch filters. Among others, multilayer interference coatings are very promissing for many applications. In this paper, we describe the design and the selection of the materials for the notch filters. Also, we present an ECR (Electron Cyclotron Resonance) ion beam enhanced deposition system which we have developed for the fabrication of notch filters.
An In-Situ Fiber Optics Sensor for Monitoring Particle Microcontamination During an IBS Optical Coating Process
Authors: Knollenberg Robert G. , Long Dale , Lopez Sharon
Published: February 2023

Research Electro-Optics, Inc. (REO) has provided alpha and beta sites to Particle Measuring Systems, Inc. (PMS) during their development of process chamber microcontamination sensors for the semiconductor industry. These real-time sensors are a desired replacement for monitor wafers currently widely in use and are equally suitable for optical thin-fílm process chamber applications. An early application of the use of silicon monitor wafers and a Surface Analysis System to study defect generation in optical thin films was described by Lalezari and Knollenberg (1989). Real-time sensors include both exhaust line sensors and in-chamber process environment sensors. An exhaust line sensor application on an IBS application was described by Knollenberg and Knollenberg (1992). The most recent cooperative effort has been with “in situ” fiber optics sensors. This work is ongoing, and some preliminary results are described here.
Comparison of Optical Coating Deposition Techniques Using Vapour Phase Precursors
Authors: Lewis Keith L , Simpson John , Milward Jonathan R
Published: February 2023

Significant interest continues to be shown in the improvement of the performance of optical coatings destined for high power laser applications. For laser applications, several factors play a role, in particular the effect of thin film microstructure. Many commercial processes rely on the use of electron beam sources. When used for refractory materials, such processes often result in coatings with a significant density of second phase inclusions. The problems arise as a result of non-uniform heating exacerbated by the poor thermal conductivity of the material present in the hearth, giving rise to the ejection of particulates. In addition the strong electrostatic forces within the chamber result in the efficient recirculation of the particles, distributing them around the coating chamber. A number of studies have recently highlighted the role that such defects play in setting the laser damage resistance of optical coatings. The defects have recently been shown [1-2] to act as immersion microlenses, enhancing electric field intensities and energy densities . Coatings with a high resistance to laser induced damage can therefore only be realised when steps are taken to avoid the formation of such defects during film deposition.
Characterization of Optical Coatings by Photothermal Deflection
Authors: Commandré Mireille , Roche Pierre
Published: February 2023

Photothermal deflection techniques (PD) have been developed at the beginning of the eighties1-2 and widely employed over the last few years to characterize optical coatings3-14. Their success originates from various advantages: the absence of any mechanical contact with the sample, the ease of implementing ( no sample preparation for example ), high sensitivity and the possibility of application to microscopy and imaging.
Laser Damage and Conditioning at Defects in Optical Coatings
Authors: Tench Robert , Kozlowski Mark , Cohen Joel , Chow Robert
Published: February 2023

Standard damage testing of multilayer dielectric optical coatings for use at 1.06 μm, typically using 100x optical microscopy, indicates that damage often initiates at microscopic defects in the coatings. These defects are known to be μm-scale nodules formed as a result of self-shadowing effects at particulate seeds deposited during the coating deposition process. It has been demonstrated that the damage threshold of these coatings can often be increased by factors of 2 or more by first illuminating the coatings at lower fluences. This pre-illumination process, called laser conditioning, is being used to increase the damage threshold of coatings for advanced laser systems being developed for Inertial Confinement Fusion research.[1]
Surace Corrosion of Thin Film Optical Components
Authors: Duparré Angela , Truckenbrodt Horst , Scheerer Friedrich
Published: February 2023

Thin film optical components on glass substrates, though designed for application in high quality optical instruments such as microscopes, binoculars, and cameras, have been found to reveal pronounced degradation effects as a result of surface corrosion on the classes. Starting with substrate roughness and defects due to the polishing process, subsequent cleaning procedures and storage of the samples under normal environmental conditions (in particular exposure to humidity) cause further development of the existing as well as the emergence of new morphological defects on the glass surfaces. After covering the substrates with optical coatings, the corrosion process is ongoing, and it is often only after a certain time of exposure to the environment that these effects become actually obvious. This, of course, gives rise to severe shortcomings regarding the overall quality of the final optical component.
Low-level scattering and localized defects in optical multilayers
Authors: Maure S. , Albrand G. , Bayle M. , Lazaridès B. , Amra Claude
Published: February 2023

Light scattering from random continuous profiles is rather well understood today and can be predicted with high accuracy1,2. However, for high-quality coatings produced on super smooth substrates (< 0.2 nm roughness), pratically the whole scattering originates from a few localized defects in the stacks. Such discrete irregularities can be detected by the presence of a “ripple” in the angular scattering3 measured with high resolution (0.01°). Therefore the characterization tools must be improved in order to reach the size, refractive index and density of localized defects that still play a key role for many applications4 such as laser damage.
Optical losses in multilayer waveguides
Authors: Ranier R. , Maure S. , Albrand G. , Mollenhauer R. , Cleva F. , Borgogno J. P. , Pelletier E. , Amra Claude
Published: February 2023

Planar optics offer an easy method for highly increasing the sensitivity of optical multilayers to absorption and scattering from interfaces and bulks. In this aim we developed in Marseilles two techniques that enable to measure the attenuation of a guided mode inside a multilayer planar waveguide1. The first technique is based on photothermal measurements that result from an absorption process, while the second involves a camera reading that registers scattering data. Though the principles of these two techniques are different, they should lead to the same value of attenuation coefficient, which is confirmed by experiment. At the present time these techniques allow to measure imaginary indices up to some 10-8 at the wavelength 515 nm.
A study of Electrochromic thin films and Devices by Photothermal Deflection Technique
Authors: Liu Xu , Chen Xong-bin , Gu Pei-fu , Ye Yong-hong , Tang Jing-fa
Published: February 2023

Recently, electrochromic thin films and thin film devices have attracted more and more interest because of strong possibility to act as smart windows and smart glass that may be widely used in the daily life[1]. The electrochromic thin film devices usually have a five layers structure: an actual electrochromic layer, an ionic conductor and an ion storage layer are sandwiched between two outer transparent electrical conductive layers, WO3 film is used as the actual electrochromic films in the general studies. The coloration and bleaching are accomplished when positive ions (Li+, H+ etc. )are moved from the ion storage, via the ionic conductor, into the electrochromic layer, or in the inverse direction. Currently, the electrochromic thin films or thin film devices are characterized by electrochemical analysis and optical spectral transmittance measurement. In fact, the electrochromic effect is a spectral absorption modulation, the investigation of the optical absorption variation during the electrochromic process may offer us more information about the process.
Defect Dominated 1.06μm Laser Induced Damage of Anti-Reflectance Coatings Designed for Use at 1.3μm
Authors: Franck Jerome B. , Riede Wolfgang , Allenspacher Paul
Published: February 2023

In this paper, we will discuss recent work that has taken place at the Laser Induced Damage Facility that is currently under development at the Institut für Technische Physik at Deutsche Forschungsanstalt für Luft- und Raumfahrt (DLR) in Stuttgart, Germany. The coatings discussed in this paper were selected for "out of band" studies to ensure that damage would proceed at fairly low levels. It is the unique nature of the damage that makes this a useful study into the mechanism of defect dominated damage. The samples were found to contain defects that were uniformly distributed through out the coating with a separation between defect sites of about 10μm. A second unique property is that the coating defect ensemble appears to be degenerate, i.e. there is a single defect type whose onset of failure takes place at a specific fluence. As higher fluence levels are attained, sets of micro-fracturing and pits form around the origional defect area that eventually coalesces into macroscopic damage. Higher fluence levels induce catastrophic coating failure on a macroscopic scale.