bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferometer for measuring polarization and birefringence
Authors: de Groot Peter , Soobitsky James
Published: February 2023

Optical instrument and component fabrication often involves sensitive measurements of the polarization state of light. A common way of determining the polarizing properties of a sample is to place it between crossed polarizers. The crossed-polarizer method is easy to perform and to understand, but it is not sensitive enough for many applications because the intensity signal is proportional to the square of the electric field. When the electric field is very small, the intensity signal may be so small that it cannot be measured with any meaningful resolution.
The Center for Optics Manufacturing
Authors: Pollicove Harvey
Published: February 2023

The Center for Optics Manufacturing (COM), located at the University of Rochester's Institute of Optics, is a collaborative effort supported by the American Precision Optics Manufacturers Association (APOMA), several academic institutions, and the U.S. Army Materiel Command. COM's mission is to research and introduce innovative technology and novel processing techniques that increase the competitiveness of the optics manufacturing base and its customers. Collaborative support ensures rapid implementation of new technologies and processes that will revolutionize optics manufacturing.
Implementation of the Ritchey-Common Test for 300 mm Wafers
Authors: Parks Robert E. , Evans Chris , Shao Lianzhen
Published: February 2023

The requirements are growing daily for large polished flat surfaces made to optical quality figure. The obvious and most reliable way of testing these surfaces is in a collimated space Fizeau cavity. Such a cavity, however, requires 2 or more optics the same diameter as the optical surface under test made to figure accuracies better than the part being tested. This makes for an expensive test. Another approach is to use the Ritchey-Common test where the single test optic is only slightly larger than the optics under test and its radius does not have to be tightly controlled. This less costly solution is traded against the increased computation of the Ritchey-Common test.
Image Acquisition for High Accuracy Interferometry
Authors: Campbell Gene , Sommargren Gary E. , Truax Bruce E.
Published: February 2023

In phase shifting interferometry, the image acquisition electronics have largely been ignored, because the overall measurement accuracy has generally been limited by the quality of the reference wave. A recently developed interferometer, the phase shifting diffraction interferometer,[1] provides a high quality reference wave, which has been measured to be better than λ/8000 rms. With such a reference wave, the interferometer accuracy then becomes limited by systematic errors in the image acquisition electronics. This paper presents a variety of issues that arise when using image acquisition electronics of the sort commonly used in commercial interferometers. A basic fiber interferometer that isolates electronics issues is described, as are simple solutions to some of the errors.
Some Early Commercial Optical Coatings: A Lighthearted Retrospect
Authors: Turner A. Francis
Published: February 2023

The present day important commercialization of optical thin film coatings grew out of work carried out in the 1940's and 1950's, largely in a few industrial laboratories. During this period the vacuum evaporation method for depositing thin films, both metals and non-metals, emerged as the most versatile. Coatings plants were developed to carry out this technique, methods were devised for in situ optical monitoring of film thickness during deposition, and a multitude of evaporant materials was uncovered, mainly by trial and error. A whole new world of applications beyond simple anti reflection coatings was discovered and coating structures became complicated multilayers. Quarterwave stacks came to be routine as dichroic beam splitters or as components of wide and narrow band spectral filters. Calculations progressed from simple vector representations through admittance chart manipulations to sophisticated computer programs for extracting reflectance, transmittance and phase data from theoretical multilayer designs. Thin film optics became established as a discipline in its own right and important theorems were evolved to aid the film designer. The author was privileged to participate in this march of events. His talk will focus on some of the commercial coating projects, as well as laboratory trivia, which he encountered along the way.
A pellicle filter for the 8-13 micron region
Authors: Holm Christian
Published: February 2023

The main elements of an infrared interference filter are the substrate, the main filter stack and the necessary blocking filter stacks. These latter stacks are placed either upon a separate substrate or on the reverse of the main filter substrate. In the 8-13 micrometer wavelength band the substrate will normally be germanium or zinc-selenide, and typical stacks consist of zinc-sulphide or -selenide/thorium-fluoride or lead-telluride/zinc-sulphide alternating layers. The choice of substrate depends upon the subsequent application of the filter, and in many cases it is desirable to have a substrate with a very low index of refraction, i.e. air. When we consider the total physical thickness of a typical stack combination to be in the region 30 - 100 micrometers, it is tempting to have a possibility for making a self-supporting or pellicle type of filter.
The Use of a Characteristic Admittance for the Analysis of Multilayer Films
Authors: Becker Roger J.
Published: February 2023

The analysis of multilayered films made up of homogeneous layers is well developed.1 Much of the analysis of films with different, e.g., sinusoidal, profiles has been carried out through approximations, such as coupled-mode theory (CMT). An exact analysis can be undertaken by solving the wave equation for a given profile or class of profiles;2 however, an even more useful approach is to make use of the concept of a characteristic admittance. All of the formulas which are familiar from the theory of homogeneous multilayered films1 hold exactly for films with continuously varying refractive indices when expressed in terms of an appropriately defined characteristic admittance, ηc. It must be noted that ηc is a generalized admittance, and will be purely imaginary within a filter stop band. Away from the stop band, ηc approaches the mean index of the filter.
Reactive Plasma Plating of Multilayer Coatings
Authors: Seddon R. I. , Temple M. D. , Klinger R. E. , Hart T. Tuttle , LeFebvre Paul M.
Published: February 2023

"Plasma Plating" as discussed in this paper is an otherwise conventional evaporation process in which coatings are deposited on substrate surfaces immersed in an intense plasma. The deposition process is characterized by very high ion currents and relatively low ion energies. A similar process has been called Ion Plating by Pulker, et al1, but since this term is associated in many people’s minds with the relatively low-current, high-ion-energy process developed by Mattox2, we have elected not to use it.
Description of a Scattering Apparatus Application to the Problems of Characterization of Opaque Surfaces
Authors: Amra C. , Grèzes-Besset C. , Roche P. , Pelletier E.
Published: February 2023

We show how the complexity of a micropolished optical surface can be investigated in detail by measurement of the distribution of scattered light.
Laser Induced Damage of Dielectric Systems with Gradual Interfaces at 1.064 µm
Authors: Ebert J. , Ristau D. , Schink H. , Mittendorf F. , Akhtar S.M.J. , Welling H.
Published: February 2023

Interfaces between adjacent layers contribute essentially to laser damage in dielectric film systems. Due to different thermal and mechanical properties of the adjacent materials stress is built up in the interface region by heating during laser exposition. Generally interface absorption exceeds volume absorption and an additional amount of heat is generated at the boundaries. In contrast to this layer adhesion is small at the interfaces. Therefore, in many cases, laser induced damage of dielectric systems starts at the boundaries of the layers.
Coatings in the Infrared
Authors: Yen Y. H.
Published: February 2023

This paper will describe work carried out principally at the Shanghai Institute of Technical Physics. It will introduce the group working on optical coatings there and will describe their research on lead telluride as an infrared high-index material. An account of recent studies in measurements techniques and monitoring methods will be included.
Ellipsometric Determination of the Optical Constants of Gold and Anisotropic Bismuth in the Form of Thin Films
Authors: Atkinson R. , Lissberger P.H. , Vallely L.A.S.
Published: February 2023

The optical constants of gold were measured throughout the visible spectrum by means of an automatic ellipsometer which operates without a phase plate. The measurements were made at various angles of incidence and with radiation incident both at the air and substrate interfaces of the optically thick gold film specimens. Moreover, the effects of vacuum deposition parameters and of surface contamination in the atmosphere were investigated. The results to be presented are compared with those of other workers and it is concluded that these measuranents constitute a good check on the random and systematic errors associated with ellipsometric observations. Such a check is a necessary preliminary step to the measurements on bismuth which involve the additional complication of anisotropy and the need to make observations at two angles of incidence, at least.
Optical Characterization of Small Samples
Authors: Edgerton Robert F.
Published: February 2023

Linear arrays of detectors and flat-panel displays have pixel-size elements of the order of 50 micrometers. Traditional spectrometers have beam dimensions much larger than this. Using available components, an instrument was designed to facilitate the making of optical measurements on small samples. Measurements of the quantum efficiency of amorphous silicon detector test pads of one square millimeter were made. The equipment is also capable of measuring the transmission and reflection spectra of small samples as well as the spectral output of small light source/filter combinations. To this end, the following components were utilized: 75 Watt xenon arc lamp with elliptical focusing mirror f/3.5 monochromator with adjustable entrance and exit slits stepper motor control of the wavelength scan of the monochromator one-to-one imaging of the exit slit to a beam-splitter/horizontal slit one-to-one imaging of the horizontal slit to the sample plane beam splitter/source-intensity detector fiber-optic sample-illumination system sample detector or calibrated detector optional detectors for transmission or reflection photocurrent to voltage amplifiers light chopper two lock-in amplifiers with ratioing capability IEEE 488 bus to computer computer control of stepper motor
Teflon Laps: Some New Developments and Results
Authors: Leistner Achim J.
Published: February 2023

The process of superpolishing using Teflon laps has been very successful and supersmooth (<1 Å rms) and very flat (λ/100) optical surfaces have been produced on a large range of amorphous and crystalline optical materials. A brief outline of the Teflon lap technique will be given.
Comparison of Vector Scattering Theory and BRDF Measurements on a Thick Silica Overcoated Aluminized Substrate
Authors: Elson J. Merle , Bennett Jean M. , Stover John C. , Apfel Joseph H. , Rancourt James D.
Published: February 2023

An aluminized substrate overcoated with a 1.83 μm thick silica film was used to test the correlation properties of the two rough film surfaces using BRDF measurements in the visible spectral region. Thin overcoating films contour the low spatial frequency roughness of the substrate but can add small amounts of high spatial frequency roughness because of the lumpiness of the coating. Thick overcoating films can destroy the low spatial frequency correlation, making the two rough surfaces completely uncorrelated. The outer silica film surface and a comparable aluminized substrate (inner surface) were measured using a mechanical stylus profiler to obtain rms roughness and autocovariance functions for both surfaces. The thick film system was then modeled by assuming a Gaussian autocovariance function for the highest frequency roughness (that could not be directly measured by the mechanical profiler) and an exponential autocovariance function for the lower spatial frequency roughness for both surfaces. This film model was used in theoretical calculations of BRDF for the 1.83 μm physical thickness silica film for s and p polarization at various angles of incidence in the visible. The calculations showed measurable differences in BRDF for correlated and uncorrelated roughness on the two surfaces. BRDF measurements suggested that the interfacial roughnesses were uncorrelated for the thick silica film.
Optical scattering and microstructure of gold and platinum coatings
Authors: Al-Jumaily G.A. , Bennett J. M. , Coulter D. R. , Raouf N.A.
Published: February 2023

Reduction of optical scattering is becoming a concern for space and astronomy applications. Scattering makes it difficult to resolve faint planets near much larger and brighter stars. In earlier work we have shown that applying ion beam processes have greatly influenced the microstructure of metal coatings. This paper reports results concerning the ion beam deposition of gold and platinum coatings onto super polished fused silica and Zerodur substrates. Coating processes employed are evaporation, ion assisted deposition (IAD), sputtering, and ion assisted sputtering (IAS). Coatings have been examined using variety of techniques listed below.
An experimental equipment for studying the whole space scattering from microrough surfaces
Authors: Zhao D.K. , Liu X. , Gu P.F. , Tang J.F.
Published: February 2023

Scattering light in an optical system caused by the rough surfaces of optical devices, is always a critical problem for the quality of the system. Even the optical surfaces that are superpo1ished will also creat considerable undesired scattering noise light, especially for the light with shorter wavelength.
Relations between Light Scattering and Microstructure of Optical Thin Films
Authors: Duparré Angela
Published: February 2023

Light scattering has been widely recognized to be of use to the analysis of thin film microstructures. In particular, advantages arise from the non-contact and nondestructive nature of the measurements.
Characterization of losses in optical coatings: the relative amount of absorption, surface and bulk scattering in multilayer waveguides
Authors: Amra C. , Cleva F.
Published: February 2023

Previous works [1] have shown how to use both guided waves and photothermal technique to provide a powerful characterization tool of losses in single thin film layers. In this continuation of the work, we use complementary techniques to assess our understanding of the phenomena in single layers, in particular about the relative amount of surface and bulk scattering in the waveguide. Moreover, new results are presented and concern the relative absorption of different materials inside the same multilayer stack.
In-situ analysis of electrochromic thin film devices with Rutherford backscattering spectrometry
Authors: Hichwa Bryant P. , Mathew J. Gordon H.
Published: February 2023

In-situ Rutherford backscattering spectrometry measurements of electrochromic devices were made to better understand their electrochemical performance. 4He++ ions with energies ranging from 2.0 to 5.0 MeV were incident on cycling electrochromic devices. We experimentally determined the changing film composition as a function of the applied device voltage. These results, when combined with transmission electron microscopy data, yield film densities as a function of depth. Significant elemental diffusion was noted in comparison with the as-deposited layer structure. We will also discuss experimental RBS analysis techniques for other complex multilayer thin film devices.
General layered media properties in connection with coating design and investigation techniques
Authors: Tikhonravov A.V.
Published: February 2023

General layered, media properties are of interest not only from the theoretical point of view, but they have a certain applied meaning also. In connection with the applied problems of thin-film optics we can distinguish several main topics in theoretical research of the layered media properties.
Techniques and Applications for Large Aperture Structured Thin Films
Authors: Sczupak Robert J. , Smith Douglas J.
Published: February 2023

The University of Rochester’s OMEGA laser system requires each of its 300-mm-diam beams to have a high degree of intensity uniformity when focused on a target sphere. This task is largely accomplished through the use of the distributive phase plate (DPP). The DPP subdivides each laser beam into a multitude of small beamlets and introduces a randomized phase variation (of 0 or π radians) to each beamlet. The beamlets are then recombined by a focusing lens and directed on the deuterium/tritium target.1,2 DPP fabrication can be accomplished two ways: by additive methods, such as coating with a thin film, or by subtractive methods, such as an ion milling process. The former process has the advantage of being the simpler of the two, but the latter yields the higher laser-damage threshold, and was recently determined to be the only acceptable method of DPP fabrication for the OMEGA Upgrade.
Synthesis and research of the optimum conditions for the optical monitoring of non-quarterwave multilayers
Authors: Grèzes-Besset C. , Chazallet F. , Albrand G. , Pelletier E.
Published: February 2023

Many optical filtering problems require the use of assemblies of layers having thicknesses which bear no obvious relationship to each other. After a brief review and comparison of some numerical techniques of synthesis which are used to obtain specific designs with given properties, we discuss the problems connected with production. The stacks are realized by Ion Assisted Deposition and Ion Plating techniques. For each technique we have reached a good knowledge of the refractive indices of the layers that we can produce starting from different materials (TiO2, Ta2O5, SiO2, ..) and we can demonstrate that conditions of deposition are correctly adjusted in order to prevent any shift of refractive index between vacuum (during growth of the film) and air (after deposition).
Infrared Optical Characterization of Superconducting Films
Authors: Tirri Bruce A.
Published: February 2023

The discovery of high temperature superconducting materials has opened up a wide range of opportunities for novel applications of superconductivity. The use of these materials in optical applications requires knowledge of scattering characteristics, optical constants, and feasibility of layering with other optical materials for device structures.
Spectroscopic Ellipsometry-Instrumentation Overview & Trends
Authors: Henderson W.R. , Piel J.P. , Stehle J.L. , Thomas O.
Published: February 2023

Ellipsometry has been extensively used since long time ago, particularly the HeNe null ellipsometer using compensator plate. This technique is very well known for its accuracy on thickness and refractive for a thin single transparent layer.
Characterization of Inhomogeneous and Absorbing Thin Films by Combined Spectroscopic Ellipsometry/ Reflection, and Transmission Measurements
Authors: Johs Blaine , Meyer D. , Woollam John A. , Elman J.F. , Long T.E. , Koberstein J.T.
Published: February 2023

Optical constants and film structure of inhomogeneous and absorbing thin films are characterized by a combined analysis of spectroscopic ellipsometry, transmission and reflection data.
Grazing Incidence X-Ray Coatings
Authors: Tirri B.A. , Bilodeau S. , Dave S. , Poirier R. , Slane P.
Published: February 2023

The throughput of a grazing incidence optical system is highly dependent on the reflectivities of the coatings used. To support ongoing work at HDOS for the Advanced X-ray Astrophysics Facility, AXAF, we have begun to look at materials and processes which maximize reflectivity in the 1-10 keV range. These processes must be scaleable and compatible with the coating of the AXAF elements. These elements are concentric paraboloids and hyperboloids ranging in diameter from 18 to 40 inches with an axial length of 40 inches. The coatings are applied to the interior optical surfaces.
Reducing Defect Density in Hafnia Optical Coatings
Authors: Chow Robert , Loomis Gary E.
Published: February 2023

The motivation for this work are observations at LLNL and the rest of the laser damage community of a correlation between increasing laser damage thresholds with decreasing defect density (ρ) on the coatings. Using data generated at LLNL, the laser damage thresholds increased from 10 to 100 J/cm2 as the ρ decreased from >100 to 1 per cm2, plotted on a log-log scale.
Antireflection coatings simultaneously effective at 1064, 532, and 355 nm
Authors: Thelen Alfred , Ebert Johannes
Published: February 2023

Harmonic generation is growing into a valuable tool to expand the availability of high power laser radiation into the visible and infrared wavelength region. Nd:YAG laser (Neodymium doped Yttrium Aluminium Garnet) for example, with a basic working wavelength at 1064nm, can be used to generate this way high power laser radiation at 532 and 355nm.
Monitoring The Growth of Ag Thin-Films Onto MICA Substrates
Authors: Corella Adalberto , Flores-Acosta Mario , Regalado Luis E.
Published: February 2023

Optical monitoring is setup into a vacuum chamber to carry out experimental measurements of the reflectivity of p- and s-polarized light entering at 45 degrees of incidence allowing the calculation of the term Δ=Rs2-Rp. It is well known from geometric optics that this term Δ equals zero for the bare substrate but it presents some variations when the surface is modified by a very thin-film growing up onto it.
Optical Thin Film Coating With Continuous Reoptimization of Layer Thickness
Authors: Chuang Chun-Shu , Ling Kow-Je
Published: February 2023

The quality of optical thin film has a decisive influence on the performance and the appearance of precise optical elements. But there are always some errors in the thickness and the refractive index due to the unstableness of physical condition in vacuum chamber. In this work we used a multi-channel optical monitoring system together with a computer optimization program to make a multi-layer thin film coating. A satisfactory result is obtained.
Applications and Processes for High Damage Threshold Sol-Gel Coatings
Authors: Staley Arthur R. , Smith Douglas J.
Published: February 2023

The Laboratory for Laser Energetic's Omega Upgrade Laser system requires the use of high laser damage threshold sol-gel anti-reflection coatings.1 The need for sol-gel coatings required the development of several different production level processes to coat a variety of components. There are over 1,200 large aperture components in the system with sol-gel coatings including, input spatial filter lenses, frequency conversion crystals (KDP), laser amplifier windows, liquid crystal devices, CCD camera arrays, final focus lenses, and blastshields. Many of these devices were hardened in an ammonia atmosphere prior to use.
Diffractive Optics replicated in Amorphous IR Glasses
Authors: Rallison Richard D.
Published: February 2023

The spectral region from about 2 microns to far IR has to be covered with only a few materials that are intrinsically transparent. Diffractive optics can be machined into tire surfaces of most materials and may be slumped or molded into a few materials. The readily available moldable materials include arsenic Trisulfide (Ar2S3) and both AMTIR 1 and AMTIR 2. All three of these amorphous IR glasses may be slumped into lenses and diffractive optics using fused silica and other glass master molds. They all begin, to flow at temperatures well below the softening temp of common plate and silica glasses. We have experimented with writing gratings in photo resist, etching the substrates and then healing the IR glasses under pressure in an oven until the pattern is transferred. We have produced zone plates and gratings interferometrically and by using lire Postscript language with typesetters and photo reduction. We have etched primarily with HF in solution and with vapors and are in the process of setting up an RIE machine to get better detail and anisotropic etch profiles. Gratings of 35 and 671/mm with near square and also sinusoidal profiles have been made recently and prior work was with blazed zone plates reduced from postscript masters. The design and production of binary masks and silica masters is well covered in the literature and won't be reproduced here. The experiments we report on are all dealing with the replication into AMTIR 1 and Arsenic Trisulfide.
Rugate filters with spatially-modulated nanostructures
Authors: Hodgkinson Ian , Wu Qi hong , McPhun Adrian
Published: February 2023

We have designed and fabricated birefringent rugate filters (birugates) by modulating the columnar nanostructure of titanium oxide and zirconium oxide during vacuum deposition. To produce the modulation the angular position of the substrate, and hence the deposition angle, is changed in a systematic way by a computer-controlled stepper drive. The deposition parameters (deposition rate ≈ 0.1nm/s, oxygen back-fill pressure ≈ 2×10–4mbar and substrate temperature ≪ 300°C) are within a regime where columnar growth tracks the applied deposition angle, according to a modified version of the tangent rule.1
Uniformity Model for Energetic Ion Processes Using a Kaufman Ion Source
Authors: Smith Douglas J. , Warner Joy A. , LeBarron Nelson
Published: February 2023

Processes that use energetic ions for large substrates require that the time-averaged erosion effects from the ion flux be uniform across the surface. A numerical model has been developed to determine this flux and its effects on surface etching of a silica/photoresist combination. The geometry of the source and substrate is very similar to a typical deposition geometry with single or planetary substrate rotation. The model was used to tune an inert ion-etching process that used single or multiple Kaufman sources1 to less than 3% uniformity over a 30-cm aperture after etching 8 μm of material. The same model can be used to predict uniformity for ion-assisted deposition (IAD).
Aspects of Plasma Assisted Chemical Vapour Deposition for Deposition of Graded Index Multilayers
Authors: Sainty Wayne G , McFall William D , McKenzie David R
Published: February 2023

Thin film structures have been produced with sinusoidal and step-wise index profiles. Results of time dependent plasma studies will be explained.
High index oxide alloys for UV applications
Authors: Simpson J , Pitt A.M.
Published: February 2023

Hafnia is the high index material of choice for ultra violet optical coatings. However, not all UV devices need the full window of transparency of hafnia and could benefit from the availability of higher index materials, particularly in the area of high performance filters. One example is the demanding requirement for bandpass filters operating in the solar blind region of the UV , where devices with a transmission band of 260-300 nm coupled with rejection levels to greater than OD10 are needed.
New high-rate automated deposition system for the manufacture of complex multilayer coatings - III. Filter Repeatability
Authors: Akiyama T. , Sullivan Brian T. , Clarke G. , Osborne N. , Dobrowolski J. A. , Howe L. , Ranger M. , Matsumoto A. , Song Y. , Kikuchi K.
Published: February 2023

In a previous paper dealing with a high-rate automated deposition system (ADS),1 it has been shown that it is possible to fabricate complex coatings accurately if the gas process control is optimized. For this ADS system, the thickness control depends upon fitting the measured transmittance of a layer to determine its thickness. However, depending on the type of filter to be fabricated, different thickness determination strategies may have to be employed in order to ensure that all the layers in the filter are deposited accurately. In addition, the thickness determination strategy for a given filter must be robust to ensure that the same filter performance can be achieved from run-to-run. In this paper, we will discuss the systematic errors that may occur with this thickness determination method and describe different thickness determination strategies for various filters including broad-band antireflectance coatings, edge filters, bandpass filters and partial reflectors. The run-to-run repeatability for this ADS system is demonstrated by depositing a set of five different filters five times in a row.
Infrared Optical Filters for Meteorological Space Instrument I.A.S.I
Authors: Lemarquis F. , Marchand G. , Amra C. , Buil Ch. , Cousin B. , Otrio G.
Published: February 2023

I.A.S.I (Infrared Atmospheric Sunding Interferometer), developed by the CNES (French Spatial Agency), will be the major intrument of the european meteorological METOP satellites. The optical part of this instrument is mainly composed of a Fourier spectrometer, followed by a three channel infrared detection device (cold box), as shown in figure 1. The spectral range of this instrument extends from 3.62 µm up to 15.5 µm. Two dichoïc filters, placed in the cold box, permit to divide this spectrum in three channels, B1, B2 and B3. A 1.54 µm laser beam serves as wavelength reference in the interferometer.
Recent Advances in Electrochromics for Smart Windows Applications
Authors: Granqvist C.G. , Azens A. , Hjelm A. , Kullman L. , Niklasson G.A. , Rönnow D. , Mattsson M. Strømme , Veszelei M. , Vaivars G.
Published: February 2023

Electrochromic smart windows are able to vary their throughput of radiant energy by low-voltage electrical pulses. This function is caused by reversible shuttling of electrons and charge balancing ions between an electrochromic thin film and a transparent counter electrode. The ion transport takes place via a solid electrolyte. Charge transport is evoked by a voltage applied between transparent electrical conductors surrounding the electrochromic film/electrolyte/counter electrode stack. This review summarizes recent progress concerning (i) calculated optical properties of crystalline WO3, (ii) electrochromic properties of heavily disordered W oxide and oxyfluoride films produced by reactive magnetron bias sputtering, (iii) novel transparent reactively sputter deposited Zr-Ce oxide counter electrodes, and (iv) a new proton-conducting antimonic-acid-based polymer electrolyte. Special in-depth presentations are given on elastic light scattering from W-oxide-based films and of electronic bandstructure effects affecting opto-chronopotentiometry data in Zr-Ce oxide. The review also contains some new device data for an electrochromic smart window capable of very high optical transmittance.
A new transparent conductive antireflection coating for deposition by sputtering
Authors: Carniglia C. K. , Laird R. E.
Published: February 2023

The simplest transparent conductive broadband antireflection (AR) coating consists of four layers: counting outward from the glass substrate, the layers could consist of indiumtin oxide (ITO) which is a transparent conductive material, a low-index material, a high-index material and a low-index material. In the standard four-layer AR coating, the high-index layer has an optical thickness which is essentially a halfwave (HW) at the design wavelength of the AR coating.1
Band edge position variations with errors in monitoring cut level
Authors: Willey Ronald R. , Machado David E.
Published: February 2023

The goal of the deposition of layers in a thin film optical coating is to achieve a reproducible result from each coating run. Various film thickness monitoring techniques may be used. The author generally favors the monitoring of the optical thickness since an optical result is what is desired. Some designs such as narrow bandpass filters are mostly dependent on the optical thickness, and others such as beamsplitters are also quite dependent on the index of refraction of the layers. If accurate knowledge of the real photometric level of transmittance or reflectance of the coated part is available from the optical monitor during the deposition of homogeneous layers, both the optical thickness and the index of refraction, and thereby the physical thickness, can be calculated.
Effect of process parameters on the amorphous and crystalline structure of indium-tin-oxide thin films
Authors: Heinz Bernd
Published: February 2023

DC magnetron sputtering is the deposition process of choice for high volume production of ITO (indium-tin-oxide) coated devices. Depending on the process conditions the deposited ITO layer is either amorphous or crystalline. Both structures are significant for the manufacturing of STN and active matrix TFT devices. The major parameters that influence the structure and the film performance are discussed, showing how temperature, voltage, gas and target quality influence the resistivity and the optical parameters.
Multilayer linear polarizer in a cemented “cube”
Authors: Baumeister Philip
Published: February 2023

An all-dielectric multilayer is encapsulated in a “cemented cube.” The index of the glass is 1.62. The goal is a linear polarizer that functions in the spectral region 420 nm to 680 nm. The angle of incidence of an axial ray is 51°, as measured in the glass. The range of angles is ±7°, as measured in the glass. The goal is a coating that manifests an average p transmittance in excess of 95% and an s transmittance of less than 1%.
Evaluation of the solutions for the 1998 design problems
Authors: Baumeister Philip
Published: February 2023

Table 2 Revised 5/25/98 (refer to summary on p. 216)
The UV Narrow-band Filters of Sequential Center Wavelengths for 300—380nm Spectrum Region
Authors: Xiao-mo Sun , Ke-jun Zu
Published: February 2023

It is known that the UV narrow-band filters are important in the specific application. In this paper the design and the fabrication of a series of narrow-band filters for sequential central wavelengths from 300 to 380nm are reported. The technical requirements of the filter designed are as follows: ■ Center-wavelength distance between every two filters is 5-10nm. Shown as figure(1). ■ The peak transmittance of central wavelength ≥ 40%. ■ The long wavelength rejection zone extends to 690-2500nm (According to different demands). ■ The short wavelength rejection zone extends to 200nm. ■ The transmittance for rejection zone ≤ 1‰.
Non-Quarter-Wave, Metal-Dielectric, Broadband Spectral-Contouring Coatings in the Visible and Near-Infrared
Authors: Morin Steven E. , Upton David , Johnson Robert L.
Published: February 2023

We have realized metal-dielectric soft coatings whose spectra match broadband, continuous, application-driven, spectral performance curves. We chose a soft coating technology because it’s relatively low batch cost allowed multiple deposition cycles. The multiple deposition cycles proved critical to success in that they allowed us to optimize the designs for unexpected process-dependant deposition material anomalies.
Purely nonlinear amplified ultralow-noise transmission using hybrid second-order DRA and PPLN-based PSA
Authors: Zhang Guibin , Chen Zhirong , Zhang Weiyu , Du Jiangbin , Guo Xiaojie , Li Zhaohui
Published: February 2023

We report ultralow-noise transmission over a 102-km single-mode fiber using a purely nonlinear amplification scheme consisting of a second-order distributed Raman amplifier (DRA) and a phase-sensitive amplifier (PSA) based on periodically poled LiNbO3 waveguides. The hybrid DRA/PSA features a broadband gain over the C and L bands and an ultralow-noise advantage, with a less than −6.3 dB effective noise figure in the DRA stage and a 1.6 dB optical signal-to-noise ratio (OSNR) improvement in the PSA stage. Compared with the unamplified link, the OSNR is improved by 10.2 dB for a 20-Gbaud 16QAM signal in the C band, resulting in error-free detection (a bit-error rate of less than 3.8 × 10−3) for the signal with a low link input power of −25 dBm. Mitigation of nonlinear distortion is also achieved by the proposed nonlinear amplified system due to the subsequent PSA.
Process-Structured Multi-Computer Architectures
Authors: Uhr Leonard
Published: February 2023

This paper will examine the wide range of parallel multi-computer architectures that have already been developed, and the far wider range of architectures that will soon become feasible, and desirable, because of the rapid explosion of very large scale integration (VLSI) technologies.
Nonlinear Optical Mechanisms and Devices for Optical Computing
Authors: Gibbs H. M. , Peyghambarian N.
Published: February 2023

Most present day optical computing uses optics only to perform linear transforms, such as imaging and Fourier transformations. Of course, computing requires decision making by various logic operations. These are usually performed by an array of detectors and an electronic computer. Sometimes a matched filter or mask (usually permanent, i.e., not programmable) performs part of the decision making. All-optical logic gates are essential for all-optical computing, and they can be used to reduce the output data rate of special-purpose all-optical processors to a rate compatible with the electronic computers they are assisting. Some of the nonlinear optics concepts and prototype devices which have the potential of performing all-optical logic operations are summarized here.
Physical Limits on Logic Operations Employing Nonlinear Optical Effects
Authors: Hellwarth R. W.
Published: February 2023

We discuss the minimum energy dissipation required to perform one logic operation by degenerate four-wave mixing of optical pulses in resonant, nonresonant, and photorefractive media.
Optical Computing in Japan
Authors: Ishihara S.
Published: February 2023

Since Japan is one of the leading countries in optoelectronics and computer technology, it is no wonder that researches in optical computing are imagined to be also very active. As is well known, much work in optical analog information processing with spatial filtering and holography has been done after notable one of Tsujiuchi. While some computer applications of optical technology such as optical storage, data transmission by optical fibers, and laser printers are being well developed, research efforts in optical computing have been just begun as in the other countries so far as it is concerned in a relatively narrow sense. In this paper, the state of the art in optical computing devices and systems in Japan is reviewed.
The Strengths and Weaknesses of Optical Architectures Based on Symbolic Substitution
Authors: Cloonan Thomas J.
Published: February 2023

Symbolic substitution (S.S.) is a parallel technique for pattern replacement within a binary array. S.S. can be used in optical architectures to perform many different operations[1]. There are several different ways to implement hardware which performs S.S. operations. This paper presents four different optical architectures based on S.S., and the strengths and weaknesses of each architecture are analyzed. This paper will deal only with architectural issues, leaving the detailed issues of implementation to future studies.
Four-dimensional optical crossbar
Authors: Lohmann Adolf W. , Stork Wilhelm
Published: February 2023

An ordinary crossbar is a two-dimensional array of N2 binary switches. N input channels communicate in any configuration with N output channels. It has been suggested before to implement the N channels as an one-dimensional array of parallel light rays, and to implement the binary switches by polarising beam-splitters and electro-optical half-wave plates. Each of the rays may be subdivided into several pixel channels in order to exploit fully the inherent parallelism of free-space optics.
A Unified Approach to Analyzing Optical Computing Systems
Authors: Athale Ravindra A. , Stirk Charles W. , Haney Michael W.
Published: February 2023

Many problems exist that available methods of computation, including those implemented by advanced parallel electronic computers, cannot solve within the bounds established by the immutable requirements of numerous significant applications. The bounds for some of these applications are generally described in terms of environmental stresses, input format, desired output, computational throughput, accuracy, size and power. In recent years, the potential capabilities of many optically implementable algorithms, architectures and technologies have been considerably enhanced. What must be done now is to construct composite system performance metrics in terms of individual algorithmic, architectural and technological capabilities that can predict whether or not a given optical system can satisfy the requirements imposed by these applications. (Clearly, a given application can be solved by more than one algorithm, each implemented on several architectures, using a wide variety of technology.) The method used to construct these composite metrics should reveal what individual performance gains must be achieved before an optical system can be applied to a given problem. Thus, a methodology that unifies heretofore unrelated aspects of algorithms, architectures, and technology will serve as a tool to point out fruitful avenues of .research to the optical computing community.
Materials and Devices for Optical Computing
Authors: Tanguay Armand R.
Published: February 2023

Summary not available.
Fingerprint Enhancement by Fourier Domain Optical Processing
Authors: Monro D M , Sherlock B G , Petts C R
Published: February 2023

Fingerprint enhancement is an essential stage in the computer processing of fingerprint images. A technique based on directional Fourier domain filtering which is capable of producing excellent results is discussed in this paper. Implementation of this algorithm on a general-purpose digital computer is slow, but using optical hardware removes the computational overhead of Fourier domain filtering.
Electronic vs. Optical Implementations of Neural Networks*
Authors: Sage Jay P.
Published: February 2023

This paper will address for the optical community the relative advantages and limitations of electronic neural network implementations in contrast to optical implementations. Its intent is by no means to be adversarial. It is hardly necessary to say that today electronics has an edge over optics in this field. The aim of the paper will be to help indicate the areas where electronic and optical implementations can each make their most important contributions and the areas in which advances in technology, particularly in optical technology, will be required.
Self-Pumped Optical Neural Networks
Authors: Owechko Yuri
Published: February 2023

Neural network models for artificial intelligence offer an approach fundamentally different from conventional symbolic approaches, but the merits of the two paradigms cannot be fairly compared until neural network models with large numbers of ”neurons” are implemented. Despite the attractiveness of neural networks for computing applications which involve adaptation and learning, most of the published demonstrations of neural network technology have involved relatively small numbers of ”neurons”. One reason for this is the poor match between conventional electronic serial or coarse-grained multiple-processor computers and the massive parallelism and communication requirements of neural network models. The self-pumped optical neural network (SPONN) described here is a fine-grained optical architecture which features massive parallelism and a much greater degree of interconnectivity than bus-oriented or hypercube electronic architectures. SPONN is potentially capable of implementing neural networks consisting of 105-106 neurons with 109-1010 interconnections. The mapping of neural network models onto the architecture occurs naturally without the need for multiplexing neurons or dealing with contention, routing, and communication bottleneck problems. This simplifies the programming involved compared to electronic implementations.
Optical Computing Research at MCC
Authors: Redfield Steve
Published: February 2023

MCC has been looking at the use of optics in computing systems as a means to overcome barriers which are inadequately addressed by electronics. The history, motivation, and successes of these efforts is presented.
Implementation of Dynamic Holographic Interconnects with Variable Weights in Photorefractive Crystals
Authors: Marrakchi A. , Patel J. S.
Published: February 2023

Elementary holographic gratings can be used to implement interconnection links betweeen individual processing elements of two distinct planes in a multi-layered optical neural network. In such networks, one issue that has a direct impact on the development of learning machines is the capability of continuously modifying a given interconnection strength (or weight) without affecting the others, when the gratings share the same volume in the photorefractive crystal (i.e., frequency-multiplexed gratings). In the following, we extend the principle of coherent erasure by the double-exposure technique to the case of elementary gratings that implement real-time optical interconnections in photorefractive materials. The effect of continuously varying the phase shift between the two recorded gratings on the diffraction efficiency is quantified, and shown to be applicable to the simulation of synapses with programmable variable weights, as would be required in a learning neural network. Issues that relate to fan-in and fan-out capabilities, which ultimately determine the achievable level of parallelism and cascadability in such processing architectures, are also addressed. An experimental interconnection system based on two-dimensional liquid crystal phase and amplitude modulators and photorefractive recording is described. Finally, an extension of the double-exposure technique to time-average erasure is then discussed.
Programmable Emulation with the Optical Reconfigurable Logic Array
Authors: Zeise EE , Guilfoyle P.S.
Published: February 2023

An optically implemented reprogrammable logic array using control logic to compute ALU primitives for emulating a general purpose programmable computer.
Entropy-Optimized Filter for Pattern Recognition
Authors: Mahlab Uri , Fleisher Michael , Shamir Joseph
Published: February 2023

One of the procedures in the generation of spatial filters for pattern recognition starts from the correlation plane and defines a desired output pattern such as the Synthetic Discriminant Function (SDF) and the desired filter is generated to yield that output for a given input.
Demonstration of Colored Optical Interconnects and Implementation of a 2 × 2 Optical Crossbar Switch with Bistable Diode Laser Amplifiers
Authors: Pan Zeqi , Dagenais M.
Published: February 2023

Bistable diode laser amplifiers have the lowest switching energy of any optical switching devices. Single and double beam usable gains in excess of 50 and 250 respectively have been demonstrated, which implies very large fan out capabilities. These devices have also been shown to be cascadable and can be operated at rates approaching 1 Gbit/s. We have used four of these devices to implement a 2 × 2 generalized nonblocking, optical crossbar switch. Any of the inputs can be connected with any of the outputs. In addition, any of the input channels can be recovered from any particular output channel using the concept of colored optical interconnects.
An Optical Respite from the Von Neumann Bottleneck
Authors: Dickinson Alex
Published: February 2023

The high end of microprocessor performance is currently dominated by Reduced Instruction Set Computer (RISC) architectures. These machines execute one or more instructions per clock cycle. A processor such as the i8601 [1] runs with a 40MHz clock - requiring that on average an instruction must be delivered to the CPU every 25nS. With DRAM access times currently at around 100nS, timely instruction delivery has become a critical constraint on processor speed.