bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simplified Method for Measuring the Surface Figure of Off-Axis, Aspheric Mirrors
Authors: Hadaway James B. , Johnson R. Barry , Feng Chen
Published: February 2023

With the advent of new technologies such as diamond turning, ductile grinding, and computer-controlled polishing, the fabrication of complex off-axis, aspheric optical components has become a routine method for the production of ultra-high resolution optical systems for multispectral applications. However, the field of metrology with respect to such components can not be said to have progressed as rapidly. In fact, the metrology of an aspheric mirror can oftentimes become much more of a burden than the surface fabrication itself. In most cases, the surface figure is more difficult to determine than the surface finish. This presentation concentrates on the issue of surface figure measurement.
Absolute calibration of optical flats using a commercial phase measuring interferometer
Authors: Evans Christopher J. , Estler W. Tyler , Parks Robert E.
Published: February 2023

So called "absolute" calibration of optical flats can be performed using a range of algorithms, each with its own limitations. At NIST we have implemented, and are intercomparing, several techniques.
Zernike reference surfaces for extending accuracy in spherical testing
Authors: Hunter G. C. , Pfluke P. L. , Selberg L. A.
Published: February 2023

Interferometric testing of spherical parts is limited in accuracy by the reference surface quality; λ/20 PV is typical. Certification of spherical surfaces to high accuracy is typically achieved using a technique that involves multiple measurements of the surface (two sphere test)1,2. This test is time intensive and requires very precise alignment of the part under test, particularly for fast surfaces. In addition, long radius surfaces may be impossible to test using the two sphere test from a practical standpoint, simply because of the length of cavity required. In order to circumvent these issues, we have examined the accuracy of storing surface maps of the reference surface for a transmission sphere and subtracting this from subsequent measurements using that sphere. The reference map is obtained by absolute certification of the reference.
Non-Destructive Estimation of Subsurface Glass Damage Using Fluorescent Confocal Microscopy
Authors: Smith Warren E. , Bui Thu-Huong , Lindquist Arne , Jacobs Stephen D.
Published: February 2023

The processes of cutting, grinding and polishing optical materials cause fractures that extend some depth below the surface. The unrelieved strain and deep cracks present below the surface can seriously affect the performance of an optical system, especially in applications requiring precision optics. Subsurface damage (SSD) can lower image contrast, cause figure instability, and contribute to catastrophic fracture in high-power lasers [1]. Different optical materials present different forms of physical damage. Techniques used to increase productivity, such as high feed rates and high lap pressures, are the most serious causes of SSD [2]. An easily employed and non-destructive SSD measurement is important for the improvement of optical fabrication techniques.
Silicon Carbide Mirror Manufacture Processes and Techniques
Authors: Ealey Mark A.
Published: February 2023

A new generation of laser mirrors were required which feature more efficient mirror designs fabricated from newer advanced materials, Silicon carbide is a factor of four better in terms of specific stiffness and resistance to thermal distortion, the key parameters for a cooled mirror. In addition silicon carbide is a factor of three better than molybdenum in terms of weight, the critical parameter for a space based optic.
Shear-mode grinding to remove residual damage from brittle-mode grinding
Authors: Hashimoto H , Imai K , Blaedel K
Published: February 2023

When grinding a brittle material, there is a fundamental difference between material removal in brittle-mode grinding and removal in shear-mode (or ductile) grinding. Brittle removal occurs by propagating cracks and usually accompanies large depths of cut with large grit and high grinding forces. It results in a surface with significant roughness and deep subsurface damage. In contrast, ductile removal occurs by plastic deformation of the material and is promoted by shallow depths of cut with small grit and low cutting forces, and leaves a specular surface and shallow subsurface damage.
New High-Precision Magnetorheological Instrument-Based Method of Polishing Optics
Authors: Prokhorov I.V. , Kordonsky W.I. , Gleb L.K. , Gorodkin G.R. , Levin M.L.
Published: February 2023

Recently, the need for fine finishing of optical workpieces has become increasingly important, A variety of polishing methods have been developed to satisfy this need. The traditional mechanical methods of polishing optical workpieces use solid shaped tools, and it's rather difficult to obtain surfaces to be polished not only of mirror quality but also physically undisturbed.
The Design, Fabrication and Testing of a 0.9 NA UV Micro-objective used for Disk Mastering
Authors: Westcott Mark , Tienvieri Ted
Published: February 2023

In response to the requirements of optical disk mastering, a new micro- objective has been developed. Disk mastering requires a small spot, dynamically focused across a moving surface. The result is a low mass lens designed for high numerical aperture, and short focal length. To offer reduced spot size and spectral versatility, this objective is achromatized from UV Argon wavelengths through red diode colors, which can be used for focus servo methods. In disk applications, a single spot is imaged instantaneously, so the design permits some field curvature across its image area. Thus, this UV micro-objective incorporates appropriate optical and mechanical attributes for this custom application.
A Key to Cost Effective Optical Systems Maximize the Number of Qualified Fabricators
Authors: Thompson Kevin P. , Hoyle Lonnie
Published: February 2023

Since the 1990 IODC, some of the most dramatic changes in the field of optics have occurred in the optics market place. In optics, the catch phrase for the early ’90s is dual-use technology. Today, the production cost of an optical system is often the key characteristic and the singular measure of feasibility. The performance goals are heavily traded, up front, to meet the cost goals. For commercial products, the cost is market driven and is usually not negotiable.
The Design of a Machine Tool for Spherical Lens Production
Authors: Gerchman Mark Craig
Published: February 2023

The Opticam®SM was designed1 in the early 1990’s for use in the investigation of microgrinding at the University of Rochester’s Center for Optics Manufacturing. A multi-axis flexible machining center was delivered2 to the University in mid-1992, and is now located at the Center’s site in Rochester. This first SM machine represented a milestone in the design of machine tools specific to the manufacture of spherical lenses. Based on the experience gained from the construction and use of the original SM, a design is now being prototyped for a new machine tool for general lens production. This presentation will describe the design of this new machine tool, the Microform®SM.
The Effect of Additives in a Commercial Coolant on the Glass Grinding Process
Authors: Puchebner B. E. , Feltzi A. , Patterson S.
Published: February 2023

Intersurface Dynamics, Inc. is one of a few companies specializing in surface preparation products designed for the optical industry. Challenge 300HT is a diamond grinding fluid made for grinding of ceramic and optical materials. It is a synthetic formulation of corrosion inhibitors, surfactants, lubricants, and non-foaming detergents. It is biodegradable with a water-like viscosity. This commercially available coolant was altered several ways by Intersurface Dynamics chemists. Different concentrations and types of foaming agents, rust inhibitors, and anti-fungal agents were added to the basic coolant. Each formulation was used to grind BK7 glass on a Rogers & Clarke G-150 generating machine at the Center for Optics Manufacturing. Machine parameters and details of the test conditions are described in a companion paper.
AFM Microscopy of Ground Glass Surfaces
Authors: Lohnes Christine E. , Quesnel David J.
Published: February 2023

The AFM can be a valuable tool used for studying the surface topography of materials. In this case, we have studied the surface topography of optical glass surfaces that have been ground with diamond matrix cutting tools. Two different tools were used in the grinding process, one ring tool contained 10 20pm diamonds and the other ring tool consisted of 6-12μm diamonds. The ring tools were set up on the OPTICAM SM system. Twelve glass samples were ground, two of each of the different optical glasses( K7, BK7, SK7, F7, SF7, and KzF6) with one sample each undergoing grinding by each of the two diamond ring tools. Grinding parameters were kept constant for all of the samples. The purpose of this study was to characterize the grinding behavior and characteristics of the different optical glasses. A goal for the future is to relate the topographical information from the AFM images to the material properties of the different glasses. In addition, it may be possible to vary the grinding parameters for the different optical glasses in order to optimize the end surface of the glasses.
Testing Aspherical Surface by "Pinhole Method"
Authors: Qiming Xin , Hong Gao
Published: February 2023

An instrument based on a special shadow method -- pinhole method was made and some experiments were done. The results show that this novel method is simple, easy to operate and suitable to test large aspherical surfaces quantitatively.
Apparatus for Measurement of Spectral Transmittance and Optical Transfer Functions of Thermal Imaging Lenses
Authors: Zorin Sergei I. , Lamekin Peter I. , Lebedinsky Yury A. , Predko Konstantin G.
Published: February 2023

The demands for optical quality are in many applications much higher than several years ago. This is especially true for the infrared optics industry. Today it is going through a metamorphosis when the optical plants have to change from the very classical ways of optics production to a much more modern approaches. Different manufacturing techniques mean also different quality levels. In order to provide the best possible quality, the strict inspection policy concerns with the specified parameters on each and every infrared component.
Ion Beam Milling Status Update
Authors: Hylton K.W. , Egert C.M.
Published: February 2023

An update on results of ion milling for figure correction of ceramic and glass optics will be presented as well as future directions being pursued.
A Model of Roughness Evolution for Ion Beam Milling of Metallic Thin Films
Authors: Egert C.M. , Thomas K.A.
Published: February 2023

A predictive model of roughness evolution during ion milling of metallic overcaots and the application of this model to optical fabrication will be presented.
Fabrication and Sphericity Measurements of Single Crystal Silicon Spheres
Authors: Leistner Achim J. , Giardini Walter J.
Published: February 2023

Spheres (balls) of single crystal silicon have become essential components in experiments to redefine Avogadro's constant, which requires the measurement of three quantities, namely, the density, the lattice parameter and the molar mass of a suitable single crystal. Silicon has proved to be the best material so far.
Research Uses of Black Glass
Authors: Parks Robert E. , Evans Chris , Asmail Clara
Published: February 2023

We got involved with black glass for 2 reasons. We wanted a glass ball to use as a reference for calibrating reference spheres in an interferometer but did not want a reflection from the rear surface of the ball. Thus the need for a highly absorbing glass. Also, we wanted some partially polished surfaces with very specific, stable and reproducible surface statistics for use in calibrating BRDF instruments. Light scattered from the bulk or back surface of clear glass would interfere with the desired scattering from the front surface and thus the need for black or absorbing glass in this case as well.
Float Polishing of Sapphire: Some Recent Developments
Authors: Seckold Jeffrey A
Published: February 2023

Several authors [1-6] have described techniques for superpolishing sapphire, some of which require elaborate machining procedures, clean room conditions and temperature control. We have achieved excellent results using simple machinery and techniques.
Pad and planetary polishing for rapid fabrication of spherical surfaces
Authors: Schmell Rodney A. , Berggren Ralph R.
Published: February 2023

The development of techniques for the rapid production of flats using polishing with a polyurethane pad was previously reported.1 The pad polishing is usually followed with brief (less than one hour) final finishing on a planetary polisher. Optics up to about 200 mm square can be handled with available equipment at Los Alamos National Laboratory (LANL). This approach has become our standard production technique.
Near-Surface Hardness of Optical Glasses and Crystals
Authors: Fang Tong , Xu Su , Lambropoulos John
Published: February 2023

Microindentation is a rapid, inexpensive technique to determine the surface hardness of solids. The hardness of solids, as determined by microindentation techniques, often exhibits an increasing hardness as the indentation load is decreased. The indentation size effect has been observed in metals [Pethica et al., 1983], in semiconductors [Bifano, 1988; Pethica et al., 1983], in ceramics [Bifano et al., 1988; Bull et al., 1989], and in glasses [Bifano, 1988; Mason et al., 1992; Li and Bradt, 1992].
Effects of Crystal Orientation in Deterministic Microgrinding of Sapphire
Authors: Golini Don , Lambropoulos John , Fang Tong , Smith Maynard B.
Published: February 2023

A new high precision optical manufacturing process for nearly hemispherical sapphire missile domes has been established at the Center for Optics Manufacturing. During development of this process, an interesting lobing phenomenon was observed, and is the subject of this paper. The substrate material used for the guided missile domes was Crystal System’s highest quality HEMEX grade sapphire. The dome was cut normal to the c (0001) orientation. When cutting a steep spherical surface in sapphire, normal to the c plane, the machining process is influenced by the change in material properties as other crystal orientations are intersected (Figure 1). The work described here is intended to explain the reason for the lobing effect through a combination of activities including: machining of sapphire domes; loose abrasive lapping of various crystal orientations of sapphire; and microhardness testing of various crystal orientations of sapphire.
The Effect of Chemically Modulated Surface Charge in the Polishing of Optical Glass
Authors: Cumbo M. J. , Fairhurst D. , Jacobs S. D. , Puchebner B.E.
Published: February 2023

The role of surface charge effects is a subject of increasing interest in optical finishing [1 - 3]. This represents an intersection of the empirically driven world of the optician with the more fundamentally oriented field of colloid science. In this paper, we examine the effect of slurry fluid chemistry on the performance of a planar continuous glass polishing process using the electrokinetic methods of colloid science to characterize the properties of optical glass and polishing agents. The goal is to understand any consequences of the chemically modulated development of electric charge on the surfaces of metal-oxide polishing agents and glass surfaces during aqueous polishing. Our discussion here is confined to experimental work using nine combinations of commercially important silicate optical glass types (Schott BK7 borosilicate crown and SF6 dense flint and Corning 7940 fused silica) and metal-oxide polishing agents (CeO2 [4], monoclinic ZrO2 and nanocrystalline AI2O3 [5]). A more extensive study of the polishing process is the subject of the first author’s doctoral dissertation [6].
Deterministic Manufacturing Process for Precision Beryllium Mirrors
Authors: Seals Roland D. , Arnold Jones B. , Mayer Jim
Published: February 2023

A deterministic manufacturing approach for the production of beryllium mirrors was developed; whereby, single point precision machining and sputter coating processes were optimized and validated.
Cold Lens Blocking Methods
Authors: Novak Robert , Marro Marlene , Tipps Joe D. , Czajkowski Walter
Published: February 2023

Loctite "Cold Bloc™", a new uv-curing blocking adhesive enables optical manufacturers to produce lens surfaces that are practically distortion free and easily debonded using a variety of eco-friendly debonding agents which eliminates the environmental concerns (solvents) of the current technique. The adhesive is a significant advance in the lens blocking process, as it eliminates heat induced blocking strain; the most significant problem encountered with current hot pitch or wax blocking methods. In addition, this blocking process reduces costly processing time, utilizes convenient ready-to-use packaging and is compatible with both conventional optical manufacturing processes and is applicable to those manufacturers using the Opticam line of equipment.
Replica Technology Up To The 1-M Range - Astronomical applications
Authors: Assus P. , Tanne J.F.
Published: February 2023

The technique of replication developped in France at OCA will be presented. Variations of apparent shrinkage due to spatial distribution of deffects on the surface of substrate will be studied . Ageing of replicas and effect of thermal cycles will be adressed as well. Positive results obtained in the replication of al m diameter parabolic concave master onto a substrate through an intermediate convex replica will be shown. Potential applications may ease the production of large convex mirrors on lightweight substrates using possibly exotic materials.
The Analytical Signal for Interferograms Evaluation
Authors: Tartakowski Valerij A.
Published: February 2023

The results of phase restoration from interferograms by testing of the optical surfaces are presented and demonstrated on computer.
Interferometric measurement of convex aspheres using holographic test plates
Authors: Burge James H. , Anderson David S.
Published: February 2023

A new interferometric test for convex aspheric optics that uses a spherical test plate with a circular computer-generated hologram is described.
Interferometric measurement of convex aspheres using holographic test plates
Authors: Burge Jim , Anderson Dave
Published: February 2023

A new method of measuring large, highly aspheric convex secondary mirrors is being pursued at the Steward Observatory Mirror Lab. This new interferometric test uses a full-aperture test plate with a computer-generated hologram (CGH) fabricated onto a concave spherical reference surface (See Fig. 1). Fringes of interference are viewed through the test plate, which is supported several millimeters from the secondary. The hologram consists of annular rings of metal spaced at intervals as small as 80 μm and as large as 500 μm. The accuracy of the surface measurement using this technique is expected to be better than 50 nm P-V and 8 nm rms for mirrors with up to 331 μm departure from the best-fit sphere. Considerably higher accuracy can be attained for less aspheric surfaces.
Production Advantages of Opticam Machining Centers for Visible and IR Optics Manufacture
Authors: Czajkowski Walter , Vakiner John
Published: February 2023

Eastman Kodak Company and Texas Instruments (Defense Systems Electronics Group) have both implemented Opticam (Optics Automation and Management) machinery into their optics manufacturing facilities through participation in the Center for Optics Manufacturing's Optics Manufacturing Modernization Program (Optimod).
Experiences with Industry Implementation and Technology Transfer at the Center for Optics Manufacturing
Authors: Richard Michele , Ruckman Jeff
Published: February 2023

The Center for Optics Manufacturing (COM) and the Army Materiel Command -- in collaboration with the American Precision Optics Manufacturer's Association (APOMA) has created a diverse and comprehensive optics manufacturing modernization program that is helping to revitalize the global competitiveness of the North American Optics industry. The key benefit of the program is the ability of COM to provide support and guidance to the technical and business resources of participating companies, transferring COM's know-how to their staffs. A significant portion of this benefit includes the tryout of Opticim and Opticam modules -- using the company's designs and parts - in order to best solve the company's business challenges.
Aspheric Surface Generation Requirements in Magnetorheological Finishing
Authors: Golini Don , Zhou Yiyang , Jacobs Steve , Yang Fuqian , Quesnel Dave , Gracewski Cheryl , Atwood Mark , Fess Ed
Published: February 2023

A manufacturing system for grinding and polishing aspheres is under development. Polishing is accomplished using the magnetorheological finishing (MRF) technique. MRF utilizes the unique properties of MR fluids to achieve high polishing removal rates. The fluid is carried through a magnetic field, in which its viscosity is increased by several orders of magnitude. The lens is polished in this viscous zone to optical quality. MRF is very effective at polishing high spatial frequency errors (microroughness) and at figuring global form errors (e.g. power), but has limitations for smoothing of mid-frequency errors. The work presented here is intended to define the problematic mid-spatial frequency regime, and to use this a criteria for the aspheric grinding process.
Surface characterization of optics for EUV lithography
Authors: Gaines D. P. , DeLong K.W. , Vernon S.P. , Stearns D.G. , Sweeney D.W. , Baker S.L. , Tichenor D. A. , Kestner R.
Published: February 2023

The surface topography of optics for extreme ultraviolet lithography (EUVL) must be precisely controlled from spatial scales extending from the full aperture (~50mm) to the wavelength of illumination (~13nm), or 7 orders of magnitude. Measurement and control of an optical surface over this range of spatial scales is challenging. This paper will present bare-surface PSD surface descriptions over these spatial scales for state-of-the-art EUVL optics.
The Economics of Traditional Versus CNC Lens Fabrication
Authors: Wiederhold Robert
Published: February 2023

Summary not available.
Fracture and Plastic Flow in Grinding and Microgrinding
Authors: Lambropoulos J. C. , Fang Tong , Xu Su
Published: February 2023

Most optical components consist of surfaces which must be manufactured via the cold working of glass: Rough grinding, microgrinding (lapping under fixed nominal pressure, or deterministic microgrinding under fixed infeed rate), and polishing [Izumitani, 1986; Karow, 1993]. The quality of the resulting optical surface may be described by its surface roughness, subsurface damage, or the residual stresses arising in the manufacturing process. The quality of the surface is determined by process parameters (pressure or infeed rate, relative speed, coolant, abrasive size and shape, etc.) and by glass chemo-mechanical properties. An optics manufacturing map will consist of a predictive scheme whereby the process parameters and the glass material properties can be used to predict the quality of the resulting optical surface.
Assessment of Microgrinding Tool Topography Using Optical Profilometry
Authors: Zhou Yi-Yang , Quesnel David J. , Funkenbusch Paul D.
Published: February 2023

Because of the complicated interactions between the tool and workpiece during the grinding process, tool topography is a useful resource for understanding the process [1-2]. Issues that can be understood by tool topography include: overall wheel surface profile, abrasive concentration on the wheel surface, effective number of cutting points, fracture and debonding of abrasives, protrusion height of abrasives, and tool wear mechanisms [2-7].
Precision Flat Polishing Of Lithium Niobate
Authors: Seckold Jeffrey A
Published: February 2023

Lithium niobate (LiNbO3) is a man-made, birefringent, electro-optically active crystal. We have used LiNbO3 in the fabrication of 75mm diameter, thin, solid Fabry-Perot etalons [1], and 50mm diameter birefringent plates for a Lyot filter. The tight tolerances on the transmitted wavefront for these components require that the material be of extremely high quality and that the surfaces be polished flat to λ/30, or better. Cutting and grinding of LiNbO3 presents no problems, since diamond cutting tools and conventional, loose, abrasive grinding can be used, but precision polishing requires special techniques.
Vertical Wheel Magnetorheological Finishing Machine for Flats, Convex, and Concave Surfaces
Authors: Kordonski W.I. , Jacobs S.D. , Golini D. , Fess E. , Strafford D. , Ruckman J. , Bechtold M.
Published: February 2023

In magnetorheological finishing (MRF), an optic is positioned above a reference surface to define a gap. A magnetorheological (MR) fluid, deposited on the reference surface, is carried through the gap. By applying a magnetic field at the gap to substantially stiffen the MR fluid in a localized region, a transient work zone or finishing spot is formed which causes removal of material from the part surface. The finishing spot is smaller than the optic. By controlling dwell time as the part moves relative to the finishing spot, the MRF process achieves surface smoothing, removal of subsurface damage, and figure correction.
Toward a Mechanical Mechanism for Material Removal in Magnetorheological Finishing
Authors: Lambropoulos J. , Yang Fuqian , Jacobs S.D.
Published: February 2023

Interest in magnetic finishing has increased greatly during the past decade [1-3]. Among the various approaches, the most recently developed process is called magnetorheological finishing (MRF) [2,3]. In MRF, a magnetorheological suspension is used to polish optical glasses and other materials. A non-uniform magnetic field is applied between the workpiece and the carrier surface to increase the flow resistance (such as apparent viscosity and yield stress) of the magnetorheological suspension. Previous studies have indicated that MRF is an efficient finishing method for polishing spheres and aspheres [4, 5]. In what follows, we show that the mechanical properties of a variety of optical materials correlate well with MRF removal rates.
Innovative Optics for Giant Telescopes
Authors: Martin H. M.
Published: February 2023

The present decade is an unprecedented period of expansion in the collective power of ground-based optical and infrared telescopes worldwide. No fewer than 13 telescopes between 6.5 m and 10 m in diameter--all larger than the most powerful telescope available before 1990--will be completed by roughly the year 2000. Some of these telescopes are designed with specific scientific goals in mind, such as high-resolution infrared imaging and spectroscopy, while others are multi-purpose instruments designed to serve the needs of an astronomical community whose observations have been limited by collecting area and resolving power for several decades. The projects are listed below.
Fabrication of the 6.5 m Primary Mirror for the Multiple Mirror Telescope Conversion
Authors: Ketelsen D. A. , Martin H. M. , Burge J. H.
Published: February 2023

We describe the process of fabricating the 6.5 m mirror for the conversion of the Multiple Mirror Telescope (MMT) to a single primary mirror. We write this summary during the loose-abrasive grinding stage. At the meeting we will present the status of the polishing process.
Measurement of large convex aspheres
Authors: Burge J. H.
Published: February 2023

Large ground-based telescope projects are currently underway that require primary mirrors as large as 8.4 meters in diameter and as fast as f/1. Since the primary mirrors are concave, they can be interferometrically measured from center of curvature using null correctors. The secondary mirrors for these giant telescopes are often convex, steeply aspheric, and large (up to 1.7 m in diameter) making them much more difficult to measure. To achieve the highest possible image quality, the mirrors must be polished to the correct shape within 20 nm rms, so they should be measured to an accuracy of 10 nm rms.
Common Processes in the Polishing of Optical and Electronic Materials
Authors: Cook Lee M.
Published: February 2023

Polishing is a tribochemical process in which specific reactions occur in the local environment of the point of contact between the abrasive particle and the substrate. This local environment is likely to be considerably different from that of the bulk liquid employed in the polishing process. Polishing may therefore be viewed as a spatially activated process. This spatial selectivity has made polishing especially useful in the planarization of electronic devices (CMP). CMP processes for a wide variety of materials (e.g., SiO2, metal, Si3N4, and Si) appear to possess a common removal mechanism, namely the production, reaction, and removal of a solvated surface layer, present either as a discrete species or as a reaction intermediate. This mechanism is reviewed within the context of evolving models for CMP contact mechanics.
Technical Developments for the Next Decade of Optical Fabrication
Authors: Fiedler Knut Holger
Published: February 2023

Before 1940, glass optics were generated by loose abrasive grinding. During World War II this started to be replaced by fixed abrasive grinding. Afterwards, in Europe, a typical supplier-driven market situation emerged. The booming post-war market for binoculars, camera lenses and eyeglasses provided the driving force behind the progress made in optical manufacturing. Therefore, from the mid-1950s onward, production sequences such as surface generation by fixed abrasive grinding, followed by labor intensive loose abrasive grinding and pitch polishing, had to be reorganized. These slow production cycles were replaced by multi-step, fixed abrasive grinding utilizing diamonds as abrasives, and by fast polishing methods.
The Importance of Standards for the U.S. Optics Industry
Authors: Kohlenberg Gene
Published: February 2023

The Optics and Electro-Optics Standards Council (OEOSC) has been formed to help the U.S. take a more active role in the development, maintenance, and administration of U.S. optics and electro-optics standards, and participate in international standards activities under ISO (International Organization for Standardization). Optics and electro-optics standards activities in the U.S. are in a time of crisis. Without support from U.S. optics and electro-optics companies, these communities will be unable to participate in the world market, and will find it progressively more difficult to engage in domestic production and sales.
Characterization of large aperture optical wavefronts using the Power Spectral Density function
Authors: Wolfe C.R. , Lawson J.K.
Published: February 2023

This paper describes interferometric measurements of large aperture optical components, and the use of Fourier techniques to characterize the data. Fourier analysis leads directly to calculation of the Power Spectral Density (PSD) function. Representing the wavefront in this manner addresses the critical issues of light scattering and diffraction which can limit the performance of high peak power laser systems. High peak power solid-state lasers can exhibit nonlinear amplification of specific spatial frequencies. These phenomena can cause "hot spots", self-focusing and beam break-up. The optical components that comprise the laser system can act as noise sources to seed these effects. As a result, the design of the optical components for these lasers use specifications based on the PSD. These specifications limit the amplitude in the mid-spatial frequency regime of the wavefront from the optical components. Once the PSD is known, the RMS surface roughness can be determined for any range of spatial frequency by integrating the PSD(v) vs. v.
Sol-Gel Replicated Optics Made From Single Point Diamond Turned Masters Exhibit Fractal Surface Roughness
Authors: Bernacki B.E. , Miller A.C. , Evans B.M. , Moreshead W.V. , Noguès J.-L. R.
Published: February 2023

Deterministic optics manufacturing, notably single point diamond turning (SPDT) has matured such that the current generation of machines1 is capable of producing refractive and reflective optics for the visible wavelength region that are quite acceptable for many applications.2 However, spiral tool marks are still produced that result in unwanted diffractive scattering from grating-like features having a spatial frequency determined by the machine feed, tool radius, and other influences such as vibration and material removal effects. Such regular artifacts are the characteristic of deterministic manufacturing methods such as SPDT.
Some Results from an Absolute Calibration for LIGO
Authors: Bourgeois Robert , Magner Joann , Stahl H. Philip
Published: February 2023

We present the results from a full-aperture calibration of an interferometer for the LIGO program. Measurements reproduce predictions to better than 0.001 rms over 200 mm. Comparisons will be made with published algorithms.
Magnetorheological Fluid Composition and Enhanced Material Removal Rates with Nanodiamonds
Authors: Jacobs S. D. , Fess E. , Gillman B. E. , Edwards H. , Golini D. , Kordonskri W. I. , Kordonski V. W. , Prokhorov I. , Yang Fuqian
Published: February 2023

Magnetorheological finishing (MRF) requires long term stability of the removal function or polishing spot, which is created by the magnetic field-stiffened magnetorheological (MR) fluid in contact with the workpiece surface. Once it is characterized for shape and magnitude of removal, the stable polishing spot serves as input to a computational algorithm for designing polishing programs to finish optics [1,2].
Advances in optical fabrication for large telescopes
Authors: Martin H. M.
Published: February 2023

Construction of larger and more powerful optical telescopes has required a number of advances in optical fabrication and testing. Necessary innovations start with the mechanical design and choice of materials for primary and secondary mirror blanks, and extend to the manufacture of the blank, and polishing and testing of the largest and most aspheric mirrors made.
Fracture and material removal mechanisms from rough grinding to polishing
Authors: Lambropoulos John C.
Published: February 2023

When manufacturing optical surfaces in brittle materials, it is often convenient to estimate the quality of the resulting surface without extensive manufacturing experiments. Such estimates include the rate of material removal, as well as typical measures of surface quality, for example surface roughness and subsurface damage. In addition, the ground surface may be in a state of residual stress which will induce an overall curvature to an optical component, especially if its aspect ratio is large. These attributes of optics manufacturing can be estimated by using a few mechanical properties of the brittle material being ground or polished.
Micro-Fabrication Grinding of Aspheric Micro-Lens Mold with ELID (Electrolytic In-Process Dressing)
Authors: Moriyasu Sei , Nakagawa Takeo , Yamagata Yutaka , Ohmori Hitoshi
Published: February 2023

Recent techniques for the fabrication of fine optical components have rapidly been developed as the expansion and development of information networks around the world. Generally optical components require higher accuracies than any other parts, and the fabrication of fine optical components require special techniques additionally. So it has been very difficult to fabricate them with high efficiency and high accuracies by conventional methods.
Precision optics fabrication using magnetorheological finishing
Authors: Golini Don , Dumas Paul , Kordonski William , Hogan Stephen , Jacobs Stephen
Published: February 2023

In general terms, the magnetorheological finishing (MRF)1 process occurs as follows (refer to Fig.1). A workpiece is installed at some fixed distance from a moving wall, so that the workpiece surface and the wall form a converging gap. An electromagnet, placed below the moving wall, generates a non-uniform magnetic field in the vicinity of the gap. The magnetic field gradient is normal to the wall. The MR polishing fluid is delivered to the wall just above the electromagnet pole pieces. The MR polishing fluid is pressed against the wall by the magnetic field gradient, acquires the wall velocity, and becomes a plastic Bingham medium before it enters the gap. Thereafter, a shear flow of plastic MR suspension occurs through the gap, resulting in the development of high stresses in the interface zone and thus, material removal over a portion of the workpiece surface. This area is designated as the “polishing spot” or removal function.
Simulation and optimization for a computer-controlled large-tool polisher
Authors: Burge James H.
Published: February 2023

Large aspheric mirrors are ground and polished at the Steward Observatory Mirror Lab (SOML) using stressed-lap polishers under computer control.1,2 Stressed-lap polishing uses large stiff circular polishing tools, which are actively deformed under computer control forcing the lap to continually fit the aspheric mirror surface. The size of the tool is typically one-third to one-sixth the diameter of the minor. As the lap is translated across the rotating minor, the lap's horizontal speed and rotation rate, the total force on the lap, and applied moments to the lap are all dynamically controlled. In order to take full advantage of these many degrees of freedom, computer simulation and optimization software has been developed. The simulation is based on Preston's relation (local removal rate proportional to pressure and relative velocity) but allows the inclusion of non-linear effects based on measured results. The optimization of polishing parameters is accomplished by a damped least squares optimization algorithm which varies the polishing parameters to obtain a desired simulated removal profile. This software has been successfully used at SOML to guide grinding and polishing of numerous large primary and secondary telescope mirrors.3 The software was developed for the stressed lap polishers at the University of Arizona, but it can be used with equal effectiveness for other types of polishers.
Development of statistical tolerancing system for optical products - Virtual PT system and Mass-Product Simulation -
Authors: Sasaki Toyoharu , Shinkai Masahiko , Higashiyama Kohichiro , Tanaka Fumiki , Kishinami Takeshi
Published: February 2023

Tolerance is very important parameter for all products to be keep stable the product performance with low manufacturing cost. However in optical products, it is very difficult to predict the productivity , optical performance and complex sensitivity of tolerance on mass-production. To solve the above problems and increase efficiency of manufacturing time and cost, This study develop the statistical tolerancing system and enable the quantitative analysis of optical performance with productivity before manufacturing. In this paper, We propose a concept of Virtual PT System(PT: Production Try) for optical products such as SLR Lenses. And we report a development of Mass-Product simulation system based on Monte-Carlo method according to the proposed concept. Furthermore, we report reliability of it’s simulation result.
Developing enabling optics finishing technologies for the National Ignition Facility
Authors: Aikens D. M. , Rich Lisa , Bajuk Dan , Slomba Al
Published: February 2023

Lawrence Livermore National Laboratory is in the process of constructing the National Ignition Facility, a half million square foot facility which will house a 192 beam laser system capable of generating the 2 million joules of ultraviolet light energy necessary to achieve fusion ignition with inertial targets by 2004. More than 7,000 meter class optics will need to be manufactured by LLNL’s industrial partners to construct the laser system1. The components will be manufactured starting in 1998 and will be finished by 2003.
Calibration of Interferometer Transmission Spheres
Authors: Parks Robert E. , Evans Chris , Shao Lianzhen
Published: February 2023

As the tolerances on optical figure get tighter and as the need to provide traceable test methods to fulfill ISO 9000 standards becomes greater, the more there is the need for a robust and reliable method to determine the residual error in interferometer test optics. This paper describes an inexpensive, quick and self-consistent method of calibrating spherical transmission optics where there is a real focus of the diverging test beam outside the transmission optic. The method is self-consistent in the sense that any given test result provides a means of calculating the variance of the result and requires no additional optic that must be calibrated or traced to another standard.
Ultraprecision Smooth Surface Finishing with ELID-Iap Grinding using Metal-Resin Bonded Wheels
Authors: Itoh Nobuhide , Ohmori Hitoshi , Kasai Toshio , Karaki-Doy Toshiro
Published: February 2023

As our society becomes increasingly information-oriented, various high-tech devices are developed to support its growth. As these high-tech devices become more and more advanced and compact in the recent years, the optical and electronic part, which make up these devices also need to be more accurate and smaller. These parts are commonly ground by loose abrasive lapping and polishing, but these methods have such disadvantages as wastewater processing problem, mechanical damages, wear by scatting abrasives, dirty workplace, and difficulty in using different grains on the same machine. For these reasons, new grinding methods are required as alternatives to the finishing method using loose abrasives. To answer to such needs, the authors have proposed a lap grinding method applying the electrically in-process dressing1) (ELID-lap grinding2)) and are carrying out studies to realize efficient and highly accurate machining. The latest bonding system which is composed of metal and resin was investigated for the ELID-lap grinding in order to improve the grinding quality by addition of the vibration absorbing function during grinding operation3). In this paper, Si which is typical material for X-ray mirror, was ground using metal-resin bonded wheels with different grain sizes, and the grinding characteristics were investigated.
Laps and Metrology for large fast aspheric convex mirrors
Authors: Smith Bryan Keener , Burge James H.
Published: February 2023

At the University of Arizona, Steward Observatory Mirror Lab (SOML), we have developed a method to make the convex aspheric surfaces for secondary mirrors. These mirrors are large, up to 1.7 meter in diameter, and depart from the best fit sphere by as much as 300 microns. The techniques proven on these large mirrors can be used with equal effectiveness on convex optics that are much smaller.
Absolute sphericity measurement: a comparative study on the use of interferometry and a Shack-Hartmann-sensor
Authors: Pfund J. , Lindlein N. , Schwider J. , Burow R. , Elßner K.-E. , Blümel Th.
Published: February 2023

High precision measurements in surface interferometry make absolute calibration methods necessary. Especially, spherical surfaces being the boundary of glass lenses have to be tested to the highest possible precision and, furthermore, it should be possible to test whole objectives at the working wavelength.
Some aspects of optical coatings in China
Authors: Tang J. F.
Published: February 2023

Up to thirty more years ago one could not find any optical coatings work in China. In the early nineteen fifties Prof. Zenglu He, the former director of the Department of Physics at the Zhejiang University, and his co-workers began to work on optical thin films. Since no vacuum equipment was available at that time, they first had to design and build coating machines, including glass vacuum systems and glass bell jars. They were some of pioneers in this field in China. Since then many optical coatings laboratories were founded in Changchun, Shanghai and other places with purpose of developing multi-layer optical coatings. Nowadays several hundreds thin film people are working in this field, mostly in research institutes and universities in Shanghai, Beijing, Changchun, Chengdu and Hangzhou etc. Their efforts are mainly concentrated on preparing various thin film optical filters for practical applications in optical and laser engineering. The following coatings, such as narrow band filters with center wavelengths from 0.20 to 20 μm, high quality laser mirrors with reflectance of 99.9% at the wavelength 632, 8nm, polarized beam spilitters with extinction ratio up to 300:1, visible and infrared circular variable filters, unprotected cold mirrors, wide band heat reflectors, color seperation filters, multilayer antireflection coatings and many more others have been produced. Almost all types of optical coatings can be produced today in many research institutes and universities only for their own projects. This indicates a significant progress in this field in China. However, most of complex optical coatings are not commercially available so far. Many optical companiesonly produce simple antireflection coatings and metallic mirrors in their production lines.
Deposition, Characterization, and Simulation of Thin Films with form Birefringence
Authors: Hodgkinson I.J. , Horowitz F. , Jacobson M.R. , Lee C.C. , Macleod H.A. , Sikkens M. , Wharton J.J.
Published: February 2023

Birefringence in optical thin films due to structure on a scale large compared to atoms but small compared to optical wavelengths, otherwise known as form birefringence, was observed almost a century ago by Kundt (1886), Braun (1985) and others. More recently, studies by Holland (1953) and other workers on obliquely deposited metal films stimulated new interest in birefringent films. The link between structure, which is predominantly columnar in evaporated thin films, and birefringence has been conclusively demonstrated through modeling and by high resolution electron microscopy. Theoretical investigations were initiated by Abeles (1958), with the goal of producing a general, elegant basis for the interaction of polarized light with anisotropic thin films. The value of such a theory lies not only in the insight into the origins and disruption of the columnar structures that pervade evaporated films, but also in the possibility that form birefringence can be exploited optically.
Ion Beam Processing for Coating onto Ambient Temperature Substrates
Authors: Kennemore C. M. , Gibson U. J.
Published: February 2023

The use of ion beams for processing optical coatings is receiving increasing attention. The ions incident on the growing film have been shown to increase the packing density and moisture resistance of the coatings. The ions deliver kinetic energy locally to the growing film, promoting a more dense structure.
Use Of Large Area Cold Cathode Ion Source For Ion Assisted Deposition Of Optical Films
Authors: Denton P.R. , Musset A. , Singh B.
Published: February 2023

We report operating characteristics of a large area cold cathode ion source suitable for use in production coaters and present data for ion-assisted deposition of SiO and other optical films.
Sputtering of multicomponent materials
Authors: Wehner G.K.
Published: February 2023

A survey is given of present, still rather sketchy, knowledge of (a) preferential sputtering of certain species in multielement materials, (b) the subsequent formation of a near surface layer with altered composition, (c) the total sputtering yields as a function of composition after steady-state conditions are established, and (d) the angular ejection distribution of different species. The basic differences between single phase alloys or compounds and multiphase alloys and materials with volatile species are described.