bluuebunny/crossref_metadata_2025 huggingface dataset:
Making a Wright-Cassegrain Universal Telescope for Halley’s Comet.
Authors: De Vany Arthur S.
Published: February 2023

The Wright-Cassegrain universal telescope system is of 12.5 inch aperture with an f/9.0 ratio and is a catadioptric, which can be converted in three various instruments.

(1). A f/2.7 Wright camera with a flat field of 5°

(2). A f/2.7 Wright-Newtonian with a flat field of 5°

(3). A f/9 Wright-Cassegrain telescope

These three instruments are with interchangeable 3 in. tubes with adjustable mounts with respective optical components converting the telescope to the desired configuration.
T.I.S. Microroughness Measurement in the Optical Shop
Authors: Guerra John M.
Published: February 2023

Optical shops are increasingly called upon to characterize not only the optical figure and macrodefects (scratch/dig) of their work but the microroughness as well. Whether the optical surface is for imaging or non-imaging applications (e.g., calendering rolls), performance depends upon meeting the specified surface microroughness. The challenge of measuring roughness of 100Å RMS co less than 10Å RMS has been met by a myriad of surface interogation techniques employing most known surface interaction phenomena, including light scattering.
Manufacture of 27 Centimeter Square KDP Crystals for the Nova Laser*
Authors: Marchi F. Thomas , Maney Richard T. , Bradley Kenneth R. , Thompson Samuel L.
Published: February 2023

Frequency conversion of the Nova laser from 1.053 μm wavelength to the second and third harmonics is accomplished using arrays of KDP (Potassium Dehydrogen Phosphate) crystals. There are 180 crystals, 27 cm2 by 10 mm thick, used in the 10 beam Nova laser. Each beam uses 18 crystals in a 3 by 3 tandem array. KDP crystals are soft, brittle, thermally sensitive, and hydroscopic. All of these factors had to be accounted for throughout the manufacturing cycle.
Unitized Mosaic Mirror Fabrication
Authors: Fantone Stephen D.
Published: February 2023

Unitized Mosaic Mirror Technology (UMMT) is a method of fabricating a large generalized aspheric mirror from smaller more readily manufactured mirror segments. This paper presents a design for a specific mirror and experimental results from scaled mirror designs including cryogenic cycling.
Testing Methods for Modern Refractive Lenses
Authors: Hopkins Robert E.
Published: February 2023

Monochromatic laser sources eliminate the need for chromatic correction Lenses with remarkable performance can now be built but it requires new approaches to fabrication and testing. Some of these methods will be described.
Mechanism of Diamond Grinding of Glass
Authors: Rupp Wiktor
Published: February 2023

This paper presents an attempt to explain the basic mechanisms of diamond grinding of glass and describes a practical method for assessing tool performance characteristics.
A reference wavefront for wavefront sensing instruments
Authors: Selberg Lars A. , Truax Bruce E.
Published: February 2023

A reference light source (RLS) was designed to allow the measurement and removal of system wavefront errors in wavefront sensing instruments. The wavefront of the RLS is produced by collimating and re-focussing the output of a laser diode onto a 1 micron pinhole aperture. The diverging spherical wavefront is usable over a numerical aperture of .65 for wavelengths greater than 700 nm. To achieve a high quality wavefront, design constraints on the pinhole are quite severe in terms of current technology. Several pinhole fabrication techniques have been explored. Methods for testing pinhole quality include electron microscopy and optical phase conjugation techniques. The wavefront is tested for non-rotationally symmetric wavefront aberrations by rotating the RLS and analyzing the changes in the relevant Zernike terms. Rotationally symmetric aberrations may then be ascertained by comparison of wavefronts measured on several instruments. Methods and results will be discussed in detail.
Multi-Facet Holographic Lens with Parallel Axes
Authors: Zhang J.C.
Published: February 2023

The characteristic of the method of the multiple exposures with the plate shifting is that parts of the optical system are fixed except the adjustment of the plate holder during the exposures. Thus the complicacies of the device and operation can be avoided. The multi-facet holographic lens with parallel axes (PMHL) can be manufactured by means of this method. Fig.1 shows a schematic diagram of the experimental arrangement for the manufacture of the PMHL. A beam emitted from a laser S is split in two by the splitter SP. The transmitted beam that undergoes the objective N1 and the L1 is converted into a collimate one, which is used as the reference beam. The reflected beam that undergoes the objective N2 and the lens L2 is converted into a convergent one, which is used as the object beam. The convergent point can be considered as the focus of the corresponding facet of a PMHL. The angle between the object and reference beams must be chosen appropriatly. If this angle is too small, the use of the PMHL will be affected easily by the 0 order of the diffraction beams.
Upgrading Conventional Interferometers to Phase-Measuring Interferometers
Authors: Stahl H. Philip
Published: February 2023

Interferometry is a well established optical shop tool. Unfortunately, many shops still rely upon manual interferogram interpretation to determine the quality of their efforts. Manual interferogram interpretation is slow, of limited accuracy, and reduces overall productivity. By upgrading in-house conventional interferometers to phase-measuring interferometers, optic shops can rapidly acquire and analyze interferograms with increased measurement accuracy and resolution, and therefore, improve productivity. Furthermore, by upgrading in-house instruments, optician training, experience, and familiarity with specific interferometers is retained.
Bound Abrasive Grinding and Polishing
Authors: Clarke Fred W.
Published: February 2023

The use of bound abrasive tools has historical roots in gem stone processing methods extending back for centuries. The broad use of bonded diamond tools for the manufacture of optical components runs only for about the last fifty years. The rapid development in the 1930's of powder metalurgy technology and its application to manufacture of optical tooling represented for the optical shop its most significant advance in methods since Newton's introduction of pitch for polishing tools. The advantage derives in that the "bound" particle is fixed in its system orientation. At work, it is maintained in its position or path and can be driven at elevated speeds; neither of which operating conditions is practically available to "loose" abrasives. The utility of bonded diamond tooling in optical shop operations is most readily perceived in the high rates of stock removal and great dimensional stability.
Component Specification
Authors: Seppala L. G.
Published: February 2023

Summary not available.
Figuring with Sub-diameter Laps
Authors: Cheng A. Y. S. , Angel J. R. P. , Brown D. S.
Published: February 2023

The method of stressed lap polishing promises to be very powerful for figuring steep aspherics. The shape of a sub-diameter lap is changed in motion under computer control to match the desired surface shape. If this is done perfectly, the problem is reduced to that of polishing a spherical surface with a sub-diameter lap. However, this simpler process still requires considerable care, to ensure uniformity of removal and control during figuring.
Fabrication of Large Aspheric Optics Using Computer Controlled Optical Surfacing (Invited paper)
Authors: Jones Robert A. , Plante Roland L.
Published: February 2023

In the near future many large optics are required for astronomy and space applications. The use of
computer controlled optical surfacing provides a way to meet this challenging requirement. This
paper describes such an automated fabrication operation, the process, and equipment. Also, the
automated fabrication of six large aspheric optics is reported.
Polishing CVD Silicon Carbide*
Authors: Fuchs Baruch A. , Brown Norman J.
Published: February 2023

Silicon carbide has a combination of properties that place it high on the list of candidates for sychrotron radiation grazing incidence reflectors. The chemical vapor deposited form has a very fine structure that permits the polisher to obtain very smooth surfaces. 5 cm diameter flats have been polished to about 1 Å rms in the 5 to 400 cycles per milimeter spatial frequency range.
Grazing Incidence Synchrotron Radiation Optics—Correlation of Performance with Metrology
Authors: Takacs P. Z. , Hewitt R. C. , Church E. L.
Published: February 2023

The performance of grazing incidence x-ray optical systems is severely compromised by arc-second slope errors arising from surface irregularities in the millimeter spatial period range. It is those errors that limit the performance of most of the aspheric optical systems in use at the National Synchrotron Light Source (NSLS) and it is those errors that are most difficult to control during the polishing process. We present here a set of scanning pinhole measurements made on a grazing incidence cylinder mirror which exhibit typical arc-second beam deflections and then correlate these measurements with surface roughness measurements made with a WYKO optical surface profiler. The average power spectral density (PSD) curve for the surface is computed from the profile measurements, and the various bandwidth-dependent statistical quantities, such as RMS roughness and slope error, which are computed from the PSD curve, are compared with the results from the scanning pinhole measurements.
Fabrication and Assembly of a High Production Injection Molded Optical System
Authors: Fantone Stephen D.
Published: February 2023

The Polaroid Spectra Camera contains an unusual telescopic viewfinder comprised of injection molded components and glass mirrors. The reverse telephoto design includes seven lenses, five aspheric surfaces, and two prisms. Figure 1 depicts the Spectra Camera and the location of the viewfinder 24 and the orientation of the optical axis OAv of the viewfinder. Figure 2 depicts the folded optical path. Note that the image is erected using a 4 mirror system. Figure 3 is a layout of the unfolded optical path. The surfaces marked by asterisks are aspheric. All of the lenses are fabricated by injection molding acrylic plastic. Camera geometry dictated a folded optical path and imposed severe packaging requirements. Figure 4 is an exploded view of the entire viewfinder assembly. All of these components (with the exception of parts 184 and 198) are machine assembled, aligned and tested using an automated assembly machine. Parts are placed into the viewfinder housing using pick-and-place units or robots and are retained by snaps, clips, or retainer housings. Cycle time for each assembly step is less than 5 seconds. The viewfinder is bore sighted by adjusting the vertical tilt of 40 (mirror 1) and the lateral position of the field mask 48. The system focus is verified using a modulation measurement technique which images a rotating radial grating through the viewfinder and onto a slit. There is no adjustment for focus. Poorly focused assemblies are discarded; hence, it is imperative that high piece part quality be maintained and that the design allow for reasonable tolerance stack up. Figures 5 and 6 depict details of a snap mount and the one mirror alignment screw.
Evaporative Deposition of Aspheric Surfaces
Authors: Rogers John R. , Martin John D. , Smith Doug S.
Published: February 2023

Evaporative deposition using a mask to produce a spatially varying thickness profile is investigated. Using dielectric evaporants with a carefully designed mask and a rotating substrate, it is possible to produce highly accurate, rotationally symmetric aspheres. The problems of surface roughness, mask misalignment, and mask form error are discussed. The use of this technique for the production of "keystone-distorted" aspheres is also investigated. By this it is meant the family of aspheres having their contour lines distorted to account for the keystone, or trapezoidal distortion which occurs when a converging or diverging beam strikes a surface obliquely. These aspheric types are useful in the design of tilted mirror systems.
Methods for Characterizing Surface Topography
Authors: Vorburger T.V.
Published: February 2023

We divide the field of surface topography characterization into profiling techniques, area techniques, and microscopy. We briefly describe each category, and give a summary of the various areas of application for each.
Design, Preparation and Use of Area Compensated Polishing Tools
Authors: Dixon J. William
Published: February 2023

Summary not available.
Removal Rates, Polishing and Subsurface Damage of Chemical Deposited Silicon Carbide
Authors: Fuchs Baruch A.
Published: February 2023

Chemical vapor deposited silicon carbide (CVD SiC) is an excellent material for use in first mirrors for synchrotron radiation beam lines. We have developed methods to grind and polish flat samples of CVD SiC down to measured surface roughness values of 1 Å RMS. This paper describes the removal rate of CVD SiC during free abrasive grinding and during polishing. The removal rate during grinding with boron carbide was found to be about 29 times slower than that of fused silica and about 58 times slower than that of BK-7 glass. The surface roughness was also measured after each grinding step in order to estimate the amount of material to be removed in subsequent operations. The measured ground surface roughness of CVD SiC was about 4 to 5 times finer than that of BK-7 and Fused Silica, respectively. At the time of the presentation, additional data on polishing rate, as well as subsurface damaged depth, will be provided.
Thin Film Distributed Phase Plates
Authors: Kessler T. , Smith D. , Sampat N. , Swales S. , Castle W. , Wohl M.
Published: February 2023

The intensity distribution in the quasi-far-field plane of a high-power laser beam is often dominated by the phase variations in the near field amplitude distribution. Diffraction limited performance can be obtained with static phase correction, adaptive optics or phase conjugation, but presently these approaches are expensive, difficult to implement or not yet available for the high-power laser. Alternatively, laser beam propagation through a distribution of phase elements in the near-field can provide improved uniformity in the far-field plane of a focusing system. The fabrication of distributed phase plates involves the combination of microelectronic mask generation and thin film vapor deposition.
A Novel Technique for the Fabrication of Infrared Irregular Polygon Scanner
Authors: Sharma G.K. , Dimri G.P. , Hradaynath R.
Published: February 2023

An irregular polygon scanner used in infrared systems has a number of plane mirror facets which are tilted at a variety of angles with respect to each other and also to the rotational axis. As the faces do not possess angular symmetry, it is difficult to manufacture irregular polygons in a block. Only methods available for mass production of such polygons are replication or single point diamond turning. Due to individual working of irregular polygon, the production cost also becomes very high.
ISO Standards on Optical Test Methods
Authors: Rosenbruch K.J.
Published: February 2023

Standardization is aimed at an internationally uniform application of terms, formulas, symbols and nomenclature to avoid misunderstandings or even unfair competition. In addition, standardization of measuring equipment avoids undetected systematic errors of different magnitude which may affect the accuracy of the measurement results obtained. Finally, standardization of measurement parameters allows measurement results obtained with instruments made by different manufacturers to be more easily compared. Standardization of test methods thus is a prerequisite for a fair quality assessment of products, and apart from being of technical and scientific interest, it is also of great commercial importance.
ISO Standards for Optical Drawings
Authors: Hildebrand Klaus
Published: February 2023

Immediately after being set up in April 1980, ISO TC172 on Optics and Optical Instruments decided to begin work on an international standard for drawings of optical elements and systems. The first need was to recognize the fact that existing general standards for mechanical components are not always adequate to express the tolerance information necessary for the production of optical elements (example: for optical workshops, surface form error tolerance must be stated in "fringe spacings", in accordance with the usual interferometric test methods). In 1980, Working Group 2 (WG2) of Subcommittee 1 (SC1) was given the task of drafting the new standard (SC1 deals with General Standards, WG2 is responsible for Indications in Optical Drawings). It has sixteen members, drawn from France, Germany, Japan, Switzerland, the UK, and the USA.
A New Ion Exchange Technique for Fabricating Radial GI lenses
Authors: Kaite Yoshikazu , Toyama Minoru , Kitano Ichiro
Published: February 2023

The ion exchange technique is widely used to produce radial gradient-index lenses, however, has a disadvantage for fabricating much larger ones. It probably takes hundreds days to make the lenses with 20 mm in diameter using this technique. In large scale imaging systems, such large radial gradient-index lenses are required.
Scanning Interference Microscopy for Surface Characterization
Authors: Lee Byron S. , Strand T. C.
Published: February 2023

Recent work has introduced the concept of scanning interference microscopy which has 3-D resolution comparable to a confocal microscope (1). This is obtained by performing interference microscopy with spatially incoherent and broadband illumination. By scanning along the optical axis, one can measure the coherence function at each point in the image. This coherence function can be processed to obtain various pieces of information. The maximum of the envelope of the coherence function corresponds to the surface height. By Fourier processing of the fringes at each point, the spectral reflectivity can be measured for that point, determining both the magnitude and the phase of the reflection as a function of wavelength. Thus a tremendous amount of information is available, but at the cost of a high processing overhead. A PC based system which provides a low cost solution with good performance will be discussed, with trade-offs between range resolution, number of points processed, and precision versus the processing time and hardware requirements analyzed. Traditionally, interferometric techniques have not been applicable to optically rough surfaces or heterogenous surfaces. This talk will discuss how scanning interference microscopy can be applied to such surfaces.
Optical Surface Inspection Using Real-Time Fourier Transform Holography in Photorefractives
Authors: Uhrich Craig , Hesselink Lambertus
Published: February 2023

We present a practical real-time optical pre-processor intended to enhance small defects in a smooth surface. The heart of the system is a photorefractive BSO phase conjugate mirror which reflects only the low intensity features of the object’s optical Fourier Transform. By adjusting the beam ratios so that only the low intensity, high spatial frequency image components are phase conjugated and inverse transformed, an image consisting of just the defects is produced. To our knowledge, this is the first use of this technique on opaque and non-periodic objects. We present experimental data showing enhancement of defects smaller than 0.2 μm.
Classification of Some Interferometers Used in Optical Testing
Authors: R. A. Cornejo , D. A. Cordero , U. R. Díaz , C. J. Pedraza , Cardona O.
Published: February 2023

There are some well known interferometers used in optical testing, which are not clearly classified in the literature as wavefront or amplitude division devices. Examples of them are the Burch, Ronchi, Linnik-Smartt and line diffraction interferometers. Another possible aspect to consider for classification, is to know if the reference wavefront is self-contained in the test wavefront. Therefore, if we do these type of classification of the interferometers, within the two above mentioned aspects, some families of interferometers can be obtained, each family showing its particular advantages or disadvantages.
Competitiveness in the US Optics Industry
Authors: Phelps James W.
Published: February 2023

There is no question that foreign competition has been successful in taking over the optical production market. In 1984, 63.5% of high technology laser optics were made in North America, with 17.5% produced through off-shore facilities. It has been predicted that by the end of 1988 that the North American share will drop to 45% and the Asian share, alone, will increase to 40.0%.
Smooth Optical Surfaces
Authors: Leistner Achim J.
Published: February 2023

Polishing plates based on teflon rather than traditional pitch retain their shape for long periods of time. That is, once they are flat they stay flat. We have polished 3-inch diameter lithium niobate crystals flat to better than λ/100 with rms roughness less than the noise in our Talystep machine (0.1 nm). The best silicon sphere we have produced (100 mm diameter) is spherical within 75 nm and we still see room for improvement. We are exploring various polishing agents to find the best material for polishing zerodur, magnesium fluoride, calcium fluoride, various grades of silica, some of the best optical glasses, and silicon, while minimizing subsurface damage. We will describe the procedures we use to commission the teflon plates and show interferograms and micro-roughness results for several of our products. We are currently expanding the upper limit on the diameter of our precision workpieces, hopefully to 8-inch. Another feature of our method is that we can also make rather thin devices as well. The lithium niobate crystal, for example is 0.2 mm thick and has an optical thickness uniformity better than 2 nm over 95% of its area as determined by our digital interferometer.
Microstructure Characterization by Angle-Resolved Scatter and Comparison to Measurements Made by Other Techniques
Authors: Jacobson R. D. , Wilson S. R. , Al-Jumaily G. A. , McNeil J. R. , Bennett Jean M. , Mattsson Lars
Published: February 2023

In many areas of technology it is becoming increasingly important to characterize the microstructure of smooth surfaces. In the optics industry, which has long been concerned with optical scatter and related microstructure of components, the requirements for better, lower scatter materials and components are becoming more demanding as optical systems evolve. For example, high-energy laser optics and laser gyro mirrors require components which are state-of-the-art, with extremely low scatter from surfaces of < 2 Å rms roughness.
HeCd Phase Measuring Interferometer Used in Photolithographic Lens Manufacture
Authors: Mahany Richard
Published: February 2023

Phase measuring interferometers have long been used as metrology systems in the manufacturing of precision optical elements and lens systems. Their computational power coupled with recent advances in rapid data taking permit users to perform complex analysis in a cost effective fashion. This paper will describe the use of a commercially available PMI Software System which was integrated with a specialized interferometer design to perform in process testing of a precision photolithographic objective lens.
Abrasive Water Jet Cutting of Mirror Cores
Authors: Baumler Mark
Published: February 2023

Eastman Kodak has combined an Abrasive Water Jet (AWJ) and a three axis robot to provide the capability to cut lightweight mirror cores. An overview of the AWJ process will be given and mirror core design flexibility resulting from this process will be shown. This process can be used for high accuracy machining of mirror cores or lower accuracy - lower cost cores. Insights into machining these types of cores will be discussed and results will be presented.
ISO 9000 and Optics
Authors: Oberheuser Joseph H.
Published: February 2023

ISO 9000, which replaces MIL-Q-9858A in the USA, is endorsed by DOD and has been adopted by the USAF. Key features of ISO 9000 and differences from MIL-Q-9858A effecting optics are discussed.
Ultraviolet Light Immobilized Lens Blocking Adhesive Performance Quantified Using Polymer Analysis Techniques
Authors: Caputo Alfred , LeBlanc Glenn
Published: February 2023

A new ultraviolet immobilized material has been formulated as a temporary holding adhesive to mount or block glass lenses during the generating and polishing operation. This recently developed "blocking" material possesses unique properties in both the liquid and solid state. The product transforms from a liquid to a solid through a controlled exposure of low intensity ultraviolet light.
Ultraviolet Light Immobilized Lens Blocking Adhesive Performance Quantified Using Polymer Analysis Techniques
Authors: Caputo Fred , LeBlanc Glenn
Published: February 2023

A new ultraviolet light cured material has been formulated as a temporary holding adhesive to mount or block glass lenses during the generating and polishing operations. This recently developed “blocking" material possesses unique properties in both the liquid and solid state. The product transforms from a liquid to solid through controlled exposure to low intensity ultraviolet light (20 to 30 mw/cm2 at 365 nm).

In the liquid state the product rheology has been devised to ensure that it meets the needs of the end user. Upon solidification, this single component product has been designed to remain rigid at room temperature after it has been cured, and release (deblock) without solvents. This paper will quantify these product parameters by employing sophisticated polymer testing equipment. The results of dynamic mechanical analysis (DMA), thermal analysis and other engineering property tests will substantiate the product's performance demands in the liquid, semi-liquid and solid stages.
The Optics Modernization Program (Optimod)
Authors: Ruckman Jeff
Published: February 2023

The Center for Optics Manufacturing (COM) has developed an innovative new program designed to effectively transfer state of the art optical technology from COM laboratories to the factory floor. By providing engineering support that promotes rapid implementation and minimizes industry's technology investment risk, the Optics Modernization Program (Optimod) will establish a viable modernized optics industrial base. By redefining technology transfer, the approach reduces implementation risk and projects savings before capital commitment.
Trends and Challenges in Optical Fabrication and Testing
Authors: Bruning John H.
Published: February 2023

Summary not available.
Introduction of the Opticam Micro SX
Authors: Bechtold Michael
Published: February 2023

The Opticam Micro SX, a multi-axis CNC precision optics machining center, will incorporate the use of newly discovered techniques and advances in deterministic microgrinding. Micro lens elements with diameters of .05-12 mm will be processed and ready for polishing.
Electrolytic Dressing of Bronze-Bondel Grinding Wheels in Fixed-Load Grinding
Authors: Bifano Thomas , Caggiano Helen , Krishnamoorthy Raji
Published: February 2023

When using bronze-bonded diamond grinding wheels, no methods of intermittent or in-process dressing have been automated to the point where sharp, continuous cutting performance can be obtained over the life of the grinding wheel when grinding hard ceramics. ELID may provide the first such continuous-dressing technique for ceramic grinding with metal-bonded wheels. With ELID, the wheel is made the anode in an electrolytic cell - a system of two electrodes and an electrolyte undergoing an electrochemical process as the result of an electric potential applied across the electrodes (note the distinction from an electrochemical cell, which generates an electrical potential in response to spontaneous electrochemical reactions between electrodes and electrolyte). The grinding coolant serves as an electrolyte, and a graphite cathode completes the cell. An applied voltage across the electrodes causes the anodic wheel bond to be continuously eroded, exposing sharp, new diamond grains before the already exposed diamonds become unacceptably dull. The graphite cathode evolves hydrogen gas, and neither gains nor loses material in the process. All of the ELID systems described to date use cast iron for cast iron fiber bonded grinding wheels, though such wheels are not common in the US [1]. Experiments have been performed at Boston University using two load-controlled grinding machines. Currently, experiments are also underway on an ultraprecision infeed-controlled grinding machine, with both iron and bronze wheels. The process dynamics for bronze are found to be markedly different than that for iron wheels. The results show significant promise for this technique in ceramic grinding with bronze-bonded wheels.
Role of etching in measurement of subsurface damage by SEM and optical microscopy
Authors: Zhou Y.Y. , Funkenbusch P.D. , Quesnel D.J. , Golini D. , Lindquist A.
Published: February 2023

Evaluation of the depth of subsurface damage (SSD) on ground glass surfaces can be performed using a taper polishing (1) or "dimpling" technique (2) to expose the glass below the surface to observation. However, accurate determination of the depth is dependent on the ability to microscopically detect cracks. An etchant is generally applied to the glass surface prior to dimpling to "open" cracks and improve their detection.
Subsurface Damage Measurements of Opticam-generated Infrared Materials
Authors: Cerqua-Richardson K.A. , Schmidt S.L. , Vakiner J.
Published: February 2023

The optical fabrication time associated with an optical component’s production most often dictates its final cost. Historically, art-driven conventional fabrication techniques used to produce infrared (IR) optics were labor-intensive, making the costs of such components prohibitive. Alternate, lower cost, fabrication technologies based on automated machine systems such as diamond turning, have been shown to be effective in generating high quality optical surfaces for some non-brittle materials. During the past year, fabrication techniques employing Opticam microgrinding technology have been demonstrated for glass and crystalline visible and infrared optical materials resulting in optical surfaces exhibiting superb figure, low roughness and subsurface damage.
Glass Polishing Experiments Using Magnetorheological Fluids
Authors: Kordonsky Wm. I. , Prokhorov I. V. , Kashevsky B. E. , Jacobs S. D. , Puchebner B. E. , Hsu Y. , Pietrowski D. , Strafford D.
Published: February 2023

A pre-prototype magnetorheological (MR) finishing machine has been constructed at the Center for Optics Manufacturing. It consists of an electromagnet, a trough for MR fluid containment and a work spindle (see Figures 1 and 2). A glass part is mounted on the spindle, positioned within the trough and above the magnet pole pieces. Polishing occurs on the surface of the glass as a function of the movement of polishing abrasives through a zone of high pressure, created by the action of the magnetic field on the MR suspension[1]. Polishing slurry in the zone of high pressure is continually refreshed by the rotation of the trough. By rotating the work spindle, an annular ring is polished out on the part (see Figure 3). The entire lens surface is polished out by adjusting spindle tilt (theta, in Figure 2) and dwell time.
Surface Figure Metrology during highly Automated Fabrication of Microoptics
Authors: Heimbeck Hans-Jörg
Published: February 2023

Optics fabrication has many common aspects independent from size and shape, but some aspects of microoptics are special. Microoptics means : ☺ small dimensions ☺ little removed material ☺ fast grinding ☺ fast polishing ☺ low weight ☺ difficult to test These properties call for automation of the production process.
Instruments for the Automatic Measurement of Radius of Curvature (AMROC™)
Authors: Manning K.R.
Published: February 2023

The paper will give a review of a family of instruments for the Automatic Measurement of Radius of Curvature (AMROC™) being developed by Roke Manor Research Ltd.
Specifications and Metrology of Surface Figure and Finish for Microlithography Optics
Authors: Zernike F.
Published: February 2023

Optical lithography has come a long way since the initial days of projection lithography in the early 70's. In the last two decades the resolution has increased by an order of magnitude, the numerical apertures used have gone from .16 to values higher than .5 and the wavelength has gone to deep UV (248nm) and is likely to go even shorter in the not too distant future. Pretty good for a technology that was supposed to be dead by the early eighties!
A Brief Survey of Pressure Calculations for Abrasive Wear Systems
Authors: Brown Normal J. , Cook Lee M.
Published: February 2023

Abrasive wear systems employ a coulomb friction process so that the power input per unit area of abraded surface is related to the product of local pressure and relative velocity by the Coulomb friction factor. The product of this power input with a process dependent efficiency factor yields the volumetric removal rate per unit area. Calculation of pressure is therefore necessary to determine abrasive removal rates. Local pressure variations are also necessary to determine local geometries such as edge rounding and roll-off. A pressure distribution poorly suited to a specific application may lead to an increase in the separation between the part and lap, permitting entrance to particle agglomerations or abrasive particles larger than would otherwise gain entrance. Such conditions lead to surfaces rougher than usual. Finally, calculations based on elastically produced pressure variations permit estimates of rates of smoothing or roughing in some applications.
Market Evolution of the Optics Industry
Authors: Trotta Patrick
Published: February 2023

Summary not available.
FAUST: generation of conic surfaces
Authors: Fähnle O.W. , van Brug H. , van der Laan C.J. , Frankena H.J.
Published: February 2023

The method FAUST (Fabrication of Aspherical Ultraprecise Surfaces using a Tube) has been described in a separate paper [Fäh95]: a modified curve generator, which uses a tubular element with a non-circular cross-section, applies loose abrasive ductile grinding with subsequent bowl feed polishing and is employed for the generation of rotationally symmetric optical surfaces. In this paper we apply FAUST for the generation of rotationally symmetric surfaces which have a longitudinal section in the shape of a conic section (in the following these surfaces will be referred to as conic surfaces [Mal92]). Figure 1 shows a vertical cross-section of the production and defines two systems of coordinates, one with respect to the workpiece (r-,y- and f-axes), the other to the tube (x-, y- and z- axes).
Rock and Roll Polishing: A New Process for Precise Optical Surface Polishing
Authors: Sasian Jose M. , North-Morris Michael
Published: February 2023

The precise polishing of optical surfaces is an important technology in the optics industry. We present a new polishing process that we call Rock and Roll polishing. This new process has the feature that it can be used to polish precise aspheric surfaces, axially and non-axially symmetric, can be scaled to polish several surfaces in parallel, and it is inexpensive.
Education and Training in Optics Fabrication: Establishing unique partnerships to address workforce training needs for optics and other high technology manufacturing
Authors: Kiernan Karen J. , Aikens David , Nichols Michael , Novak Robert F. , Czajkowski Walter
Published: February 2023

Over the past several years much concern has been voiced about the lack of trained technologists to support high-technology industry and manufacturing in the United States. Attracting and training both new members and upgrading and retraining current members of this area of the workforce has many challenges to address before adequate numbers of well trained individuals will be available to fill the growing demand and help secure our nation’s economic industrial edge. Among the concerns are the lack of effective training programs, available funding, career image, and vehicles to educate the public on the availability of positions and excellent rate of compensation. These concerns which effect many areas of industrial manufacturing have been highlighted by government organizations, such as the Department of Labor statistics, and professional journals and publications. In the specific area of optical fabrication, journals such as “Laser Focus: and Photonics Spectra” have dedicated articles and editorials discussing the lack of optical fabrication training resources in the United States. Examples of other vocational areas lacking skilled workers, such as precision machinists, are reflected in articles in other publications such as “Manufacturing Engineering”.
Deterministic Microgrinding of Aspheres
Authors: Fess E. , Ruckman J.
Published: February 2023

The Moore Asphere Grinder was designed and built by Moore Tool (Bridgeport, CT) with inputs from the COM-led Machine Technical Advisory Board. The scope of this latest COM machine development project was to design and build a cost effective, high precision machine that would deterministically microgrind aspheric optical components in brittle optical glass materials. The ground surfaces had to be compatible with COM and QED-developed magnetorheological finishing processes. Moore Tool’s design goals were to design a machine dedicated to grinding aspheres up to 100mm in diameter in a production environment (see page 2 for machine specifications). With the new capabilities of this grinder and the magnetorheological finishing process, COM’s goal was to demonstrate a 10x reduction in the cost of asphere fabrication.
The Improved Stability of Optical Interference Coatings Produced By Ion Beam Sputterin
Authors: Cole B.E. , Moravec T.J. , Ahonen R.G. , Smith D. L. , Ehlert L.B.
Published: February 2023

Optical Interference coatings for the visible and near infrared are usually made of oxide thin films. Many oxide coatings produced by popular thermal deposition techniques, e.g. electron beam, are less than bulk density and absorb water from the atmosphere. We present data on coatings prepared by ion beam sputtering that are very dense and show very little water content. This results in coatings that are more stable in the environment.
A Monitoring Method, of the Arbitrary Thickness of Optical Thin Films and. Their Error Simulation
Authors: Zhen Zhu , Wensheng Li , Yansen Hua
Published: February 2023

In an optical multilayer system of the specifically desired, spectral character, usually the film system designs produced by automatic synthesising consist of multi-layer films of unequal thicknesses. A monitoring technique of film thickness is of great importance to preparing necessary films.
Ultraviolet Dielectric Multilayer coatings With Extended High Reflectance Band
Authors: Hui Yuan , Liying Han
Published: February 2023

The principal techniques for achieving multilayer coatings of ZrO2-SiO2 with reflectance higher than 98% in most laser lines over the spectral region 240-370 nm are given.
Laboratory Methods to Study Thin-Film Phenomena
Authors: Bowling R. A.
Published: February 2023

During the past fifteen years, materials characterization techniques have undergone dramatic changes, particularly with regard to the development of new spectroscopic techniques for the study of thin films. Most of these spectroscopic techniques use as primary sources electron beams, ion beams, or x-rays. They include such techniques as Auger electron spectroscopy (AES), electron induced x-ray fluorescence (which is also known as electron microprobe analysis (EMP) and includes both energy dispersive spectroscopy or x-ray analysis (EDS or EDX) and wavelength dispersive spectroscopy or x-ray analysis (WDS or WDX)), Rutherford backscattering spectroscopy (RBS), secondary ion mass spectrometry (SIMS) which includes ion microprobe mass analysis (IMMA), x-ray induced x-ray fluorescence (XRF), and x-ray photoelectron spectroscopy (XPS) which is also known as electron spectroscopy for chemical analysis (ESCA). For each of these techniques the detected species is also either electrons, ions, or x-rays.
Theory of Light Scattering from a Rough Surface with an Inhomogeneous Dielectric Permittivity
Authors: Elson J. M.
Published: February 2023

First-order perturbation theory is used to calculate the scattering of a plane wave from the surface of a semi-infinite medium; the surface is slightly rough and the scattering medium is isotropic but has optical constants which vary as a function of position over the surface, i.e., the material has an inhomogeneous dielectric permittivity. Both the roughness and dielectric permittivity perturbations, which are treated as random variables, can independently cause scattering, and there is generally interference between the two scattered fields. The scattering depends on the autocovariance functions for the surface roughness and dielectric fluctuations and their cross correlation properties. Thus, the polarization ratio between the p and s angle-resolved scattering components is found to be a variable that depends on the autocovariance functions and cross-correlation between the surface roughness and dielectric fluctuations. This result is unlike predicted scattering caused by roughness or dielectric perturbations alone; in these cases the polarization ratios do not depend on the statistical properties of the perturbation.
Specifications and Measurements of Large Coated Optics
Authors: Bennett Harold E. , Elson J. M.
Published: February 2023

Large coated optics are used in signal optics to maximize light gathering power so that faint objects can be revealed, and in power optics to maximize focal spot intensity. In both types of applications wavefront distortion and scattered light are of concern. Substrate specifications thus usually include optical figure, zonal tolerance, micro roughness, and allowed surface defect levels. In refractive elements, optical homogeneity is also of crucial importance. The role that single or multilayer dielectric coatings can play in modifying these specifications is not generally appreciated. For example, film thickness nonuniformities will change the apparent optical figure and may increase near angle scatter significantly. Film inhomogeneities are predicted by Elson* to have a synergistic effect on microirregularity scattering, and film-induced surface plasmon excitation may be significant in ultraviolet wavelength regions if silver or aluminum undercoatings are used. Cleanliness is crucial since coating defects may produce unacceptable scatter and even catastrophic damage. A discussion of the magnitudes of these effects, possible specifications for controlling them, and verification techniques will be given.
Refractive Index and Inhomogeneity of Thin Films
Authors: Borgogno S. P. , Flory F. , Roche P. , Schmitt B. , Albrand G. , Pelletier E. , Macleod H. A.
Published: February 2023

The fact that the optical characteristics of materials in thin-film forms are generally different from those of the same materials in bulk form is well known. The differences depend very much on the conditions under which the deposition has been carried out. A good understanding of these differences, their causes and the influence of deposition parameters is vital if we are to be able to improve coating quality.
Comparison of Optical Scatterometer and Optical Profilometer Techniques for Microstructure Characterization of Optical Surfaces
Authors: Jacobson R.D. , Wilson S.R. , Al-Jumaily G.A. , McNeil J.R.
Published: February 2023

Many systems have been devised to characterize smooth surfaces. Some systems measure the optical scatter characteristics of surfaces to provide information concerning surface microstructure; examples include the angle-resolved scatter apparatus (scatterometer) and the total integrated scatter (TIS) apparatus. Other instruments measure the surface profile more directly; examples include the mechanical profilometer (e.g. Talystep and Dektak) and the optical profilometer (e.g. WYKO). The optical profilometer measures the optical phase of a surface to derive a surface profile. If the sample is coated with optically transmitting films, the "surface" is not well defined optically. For these samples, strictly speaking, none of the optical techniques should be used to determine surface microstructure.
Methods of Determining Thin Film Stress
Authors: Thomas Norman L.
Published: February 2023

Thin film stress can play an important part in the fabrication of flat media on thin substrates, and can cause unwanted deformations and failure. The stress parameter has been shown to be adjustable by varying the deposition parameters during thermal evaporation or sputtering. For example, ion assisted reactive evaporation is a deposition technique which has been shown to be useful in controlling stress, in addition to other thin film parameters. The successful application of these techniques requires that the stress be monitored, in situ, during a coating run, or, by means of a piggy-backed stress monitor disk whose curvature is measured after the coating run.
The Effect Of Space Contamination On Optical Coatings
Authors: Raouf Nasrat A , Al Jumaily G. A.
Published: February 2023

The effects of certain space contaminants on the optical properties of coatings are presented. Single layer coatings of both silicon and aluminum oxynitride deposited on silicon substrates using ion assisted deposition method are examined.
Trends in Interference Coatings for Optoelectronics
Authors: Brown R G W
Published: February 2023

Optoelectronics is widely seen as a dominant technology of the 21st Century. Optical Interference Coatings play an important role in many optoelectronic devices and systems. The next generations of optoelectronics will place considerable extra demands on the performance of optical interference coatings to ensure successful operation. This lecture will examine these new demands in detail, focusing on practical fabrication and testing problems, but also addressing the theoretical basis of coatings as their size and wavelengths of operation become ever smaller.
Broadened Polarization Bandwidth for Thin Film Slab Polarizers Using Adjacently-Centered Long Wave and Short Wave Pass Stacks
Authors: Browning Stephen D.
Published: February 2023

Brewster’s angle thin film polarizing beamsplitters utilize the polarizing region on the long wavelength side of a long wave pass stack of layers. The bandwidth over which effective polarization splitting of the incident light occurs is limited by the ratio of the refractive indices of the coating materials. (A higher ratio gives a broader bandwidth.) For certain applications, the bandwidth must be broad enough to accommodate multiple spectral lines. Immersed designs will accomplish such spectral broadening. However, they are not suitable for high energy laser applications due to low laser damage thresholds of optical cements. The air-spaced cube polarizer, while nominally an immersed design, does not exhibit such bandwidth broadening. A straightforward method for broadening the polarization band of a Brewster’s angle slab polarizer is to combine two separately-centered polarizers into one design.
Analysis of the transfer coefficients in layered media
Authors: Kaiser Hans
Published: February 2023

With respect to reflectance and transmission of electromagnetic waves layered media can be regarded as linear input-ouput-systems ℒ. The transfer coefficients - rs or rp for instance - are so-called system functions of ℒ.