This PDF file contains the front matter associated with SPIE Proceedings Volume 8126, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Optical manufacturing and testing technologies are critical to enabling NASA's future high priority missions. A technology assessment roadmap for Science Instruments, Observatories and Sensor Systems (SIOSS) was developed for the NASA Office of Chief Technologist. This roadmap identifies a wide range of specific challenges (including some which require optical manufacturing and testing technology) that require maturation over the next 10 years.

We describe progress on a novel process-chain being used to produce eight 1.4m hexagonal segments as prototypes for the European Extremely Large Telescope - a Master Spherical Segment as a reference, and seven aspheric segments. A new pilot plant integrates a bespoke full-aperture test-tower designed and built by OpTIC Glyndwr, with a Zeeko 1.6m polishing machine. The process chain starts with aspherising hexagonal segments on the Cranfield BoX™ grinder, followed by smoothing, corrective-polishing and edge-rectification using the Zeeko CNC platform. The paper describes the technology and progress, and anticipates how the process-chain is expected to evolve through the seven segments to increase both process-speed and surface-quality.

Stress mirror polishing is considered as one of several polishing technologies for the generation of the aspherical shaped primary mirror segments of the thirty meter telescope (TMT). For stress mirror polishing it is essential to precisely know the elastic response of glass ceramic substrate materials under a given deformation load. In the past it was experimentally shown that glass ceramics do not respond instantaneously to loading and unloading conditions, this effect was called "delayed elasticity." Recently SCHOTT has shown that it is possible to use a model to predict the characteristic thermal expansion behaviour of individual ZERODUR® batches for a given temperature profile. A similar approach will be used to predict the delayed elastic behavior of ZERODUR® under time dependent loads. In this presentation the delayed elasticity effect of ZERODUR® is reviewed. The delayed elastic response of the material to load conditions is shown and discussed. First results of a model approach based on experimental results and tools that have been built up for the modelling of the delayed elasticity effect of ZERODUR® will be presented.

In the recent past, SCHOTT has demonstrated its ability to manufacture large light weighted ZERODUR® mirror blanks for telescope projects like the GREGOR solar-telescope, for example. In 2010, SCHOTT was commissioned with a study aimed at developing a design for the M5 mirror blank of the ESO E-ELT. The tip and tilt M5 mirror of the European Extremely Large Telescope (E-ELT) requires a demanding approach in light weighting. The approximately 3.1 m x 2.5 m elliptical plano mirror is specified to a weight of less than 500 kg with high Eigenfrequencies and low deformation under different inclination angles. The study was divided into two parts. The first part focused on coming up with an optimized light weighted design with respect to performance and processability with finite element modeling. In the second part of the study, a concept for the processing sequence including melting, cold-processing, acid etching and handling of the M5 blank was developed. By producing a prototype section, SCHOTT demonstrated its ability to manufacture the demanding features, including pockets 350 mm in depth, thin walls and sloped pocket bottoms. This paper outlines the results of the design work, processing concept and demonstrator fabrication.

Deformable mirrors using polyvinylidene fluoride (PVDF) membranes in a bimorph configuration have been previously investigated. Kratos Defense and Security Solutions, in partnership with Advanced Optical Systems, Inc. and NeXolve, Inc., have been evaluating the utility of unimorph PVDF films for fabrication of deformable mirrors. Actuation using a unimorph film is achieved by creating a gradient in the piezoelectric response of the film through a proprietary process. This eliminates the requirement to bond multiple films and improves the optical quality of the films. To assist in the development and design of the films, a multiphysics design tool has been developed by tightly integrating several commercial software packages. This tool has then been used to model the performance of the films and extract significant material parameters. This paper reports on the initial modeling results and characterization of this novel material.

The first monolithic ZERODUR® 4 m class mirror was ordered by the German Max Planck Institute for Astronomical Physics in 1968. A ratio of 1:6 for thickness to diameter ratio ensured the necessary stiffness to minimize deformation under gravity load. The technological ability to actively compensate the bending of the mirror substrate under gravity initiated the development from heavy non active thick mirror substrates to ever thinner thicknesses starting with the NTT, the New Technology Telescope of ESO. The thinner the mirror substrates are becoming the more demanding are the requests on homogeneity of material properties to ensure best performance over the clear aperture at every spot. In this paper we present results on material properties achieved for the 4 m class mirror substrates recently delivered by SCHOTT. The CTE homogeneity, the internal quality regarding striae, bubbles and inclusions as well as stress birefringence data are reported. Improvements in CNC processing and overall manufacturing process for the very thin 4 m class blanks are discussed.

Optical engineering projects often require massive data processing with many steps in the course of design, simulation, fabrication, metrology, and evaluation. A MATLAB™-based data processing platform has been developed to provide a standard way to manipulate and visualize various types of data that are created from optical measurement equipment. The operation of this software platform via a graphical user interface is easy and powerful. Data processing is performed by running modules that use a proscribed format for sharing data. Complex operations are performed by stringing modules together using macros. While numerous modules have been developed to allow data processing without the need to write software, the greatest power of the platform is provided by its flexibility. A developer's toolkit is provided to allow development and customization of modules, and the program allows a real-time interface with the standard MATLAB environment. This software, developed by the Large Optics Fabrication and Testing group at the University of Arizona, is now publicly available.** We present the capabilities of the software and provide some demonstrations of its use for data analysis and visualization. Furthermore, we demonstrate the flexibility of the platform for solving new problems.

The purpose of this research was to construct a measurement system which can fast and accurately analyze the residual stress of the flexible electronics. The transparent conductive oxide (TCO) films, tin-doped indium oxide (ITO), were deposited by radio frequency (RF) magnetron sputtering using corresponding oxide targets on PET substrate. As we know that the shadow Moiré interferometry is a useable way to measure the large deformation. So we set up a double beam shadow Moiré interferometer to measure and analyze the residual stress of TCO films on PET. The feature was to develop a mathematical model and combine the image processing software. By the LabVIEW graphical software, we could measure the distance which is between the left and right fringe on the pattern to solve the curvature of deformed surface. Hence, the residual stress could calculate by the Stoney correction formula for the flexible electronics. By combining phase shifting method with shadow Moiré, the measurement resolution and accuracy have been greatly improved. We also had done the error analysis for the system whose relative error could be about 2%. Therefore, shadow Moiré interferometer is a non-destructive, fast, and simple system for the residual stress on TCO/PET films.

The MicroFinish Topographer (MFT) is the result of an interest in directly measuring the surface roughness of large optics without the need for using replicas that may degrade the measurement data and that contaminate the surface. Once the MFT proved itself on large optics it was immediately suggested that a similar device should be designed for small optics. All this really took was turning the original MFT upside down and placing small specimens on a holder. This one device tests samples from 10 mm diameter to 10 m with phase measuring interferometry that does not need vibration isolation. Further, the MFT form factor makes it ideal for use in doing on-machine surface finish metrology.

The scanning long-wave optical test system (SLOTS) is under development at the University of Arizona to provide rapid and accurate measurements of aspherical optical surfaces during the grinding stage. It is based on the success of the software configurable optical test system (SCOTS) which uses visible light to measure surface slopes. Working at long wave infrared (LWIR, 7-14 μm), SLOTS measures ground optical surface slopes by viewing the specular reflection of a scanning hot wire. A thermal imaging camera collects data while motorized stages scan the wire through the field. Current experiments show that the system can achieve a high precision at micro-radian level with fairly low cost equipment. The measured surface map is comparable with interferometer for slow optics. This IR system could be applied early in the grinding stage of fabrication of large telescope mirrors to minimize the surface shape error imparted during processing. This advantage combined with the simplicity of the optical system (no null optics, no high power carbon dioxide laser) would improve the efficiency and shorten the processing time.

The canonical Zernike phase-contrast technique transforms a phase object in one plane into an intensity object in the conjugate plane. This is done by applying a static π/2 phase shift to the central core (~ λ/D) of the PSF which is intermediate between the input and output planes. Here we present a new architecture for this sensor. First, the optical system is simple and all reflective. Second, the phase shift in the central core of the PSF is dynamic and or arbitrary size. This common-path, all-reflective design makes it minimally sensitive to vibration, polarization and wavelength. We review the theory of operation, describe the optical system, summarize numerical simulations and sensitivities and review results from a laboratory demonstration of this novel instrument.

A dynamic profiler is presented that is capable of precision measurement of surface roughness in the presence of significant vibration or motion. Utilizing a special CCD camera incorporating a micro-polarizer array and a proprietary LED source, quantitative measurements were obtained with exposure times of <100 μsec. The polarization-based interferometer utilizes an adjustable input polarization state to optimize fringe contrast and signal to noise for measurement of optical surfaces ranging in reflectivity from 1 to 100%. A new phase calculation algorithm is presented that nearly eliminates phase-dependent errors resulting in shot noise limited performance. In addition to its vibration immunity, the system's light weight, <5 kg, compact envelope, 24 x 24 x 8 cm, integrated alignment system, and multiple mounting options facilitate use both directly resting on large optical surfaces and directly mounted to polishing equipment, stands, gantries and robots. Measurement results presented show an RMS repeatability <0.005 nm and an RMS precision < 0.1nm which are achieved without active vibration isolation.

The technical requirements for large future space optics are becoming more and more challenging. This is particularly the case with respect to thermal stability under cryogenic conditions. During the past two years, ECM together with its industrial partners carried out extensive cryo-stability tests of its HB-Cesic® optical material under a range of conditions. In this paper we report the test configurations and results of two of these tests and qualification campaigns. The first of the tests was carried out with a 600-mm HB-Cesic® mirror that was polished directly without any overcoating. The second of the tests was carried out with an 800-mm HB-Cesic® mirror whose optical surface was coated with a silicon layer prior to polishing. The 600-mm mirror was tested to a cryogenic temperature of 93 K. The 800-mm mirror was tested to a cryogenic temperature of 18 K.

Shaping processes, e.g. cnc grinding, loose abrasive grinding and fluid jet polishing have been investigated experimentally for the level of sub-surface damage caused analyzing different process characteristics.

Fabrication and testing of optical elements with precision up to lambda/100 or freeform optics for high-end products are always a challenge. By incorporating special process chains and self-developed metrology equipments, optics of various materials can be made at Zeiss with excellent shapes and finishes. This is demonstrated by CaF₂ and fused silica optics.

This work deals with the chemo-mechanical sub-aperture polishing of glass lenses using spiral tool path and pressure-inflated membrane tools. Current trends in manufacturing precision optics in Europe go to smaller lot sizes and an increasing ratio of custom specific lens design. This requires deterministic processes as well as methods for an analytical process set-up without empirical try-outs. Chemo-mechanical polishing is typically applied for pre-polishing step, which aims for smoothing the surface with moderate shape correction. But due to kinematic effects the spiral-polishing process often shows changes in the radius of curvature, which are right now corrected by empirical try-outs and iterative corrections. This paper suggests an analytical tool for the compensation of these effects and contributes doing so to an efficient pre-polishing of aspheres. A mathematical model calculates the local distribution of material removal. It is based on Preston's equation and takes into account the influence of the major input parameters, such as feed rate, spindle revolutions and spot size. The given results show a significant reduction in shape deviation applying this methods compared to a polishing process without any compensation.

Following a 'Call for Tenders' by the European Southern Observatory (ESO) a collaboration headed by OpTIC Glyndwr Ltd is producing seven prototype segments for the European Extremely Large Telescope (E-ELT). Each hexagonal segment is 1.4 m corner-to-corner with a base radius of curvature (ROC) of 84 m and the combination of 984 segments will lead to a primary mirror with a diameter of 42 m. The polishing of the prototype segments occurs in-house at OpTIC Glyndwr using a Zeeko polishing machine, while in situ interferometry is undertaken using a specifically designed optical test tower built above the polishing machine. To confirm the base radius of curvature of the prototype segments an on-machine non-contact profiler is used. The profiler attaches to the bridge of the polishing machine and is removed during polishing. The design of the profiler is based upon a nanometre optical component measuring machine (NOM) system, originating from the sychrotron optics community. This instrument determines the height at a series of points across the surface through the integration of measured slope data. This paper presents the operation of the OpTIC-NOM as both an on-machine and off-machine profiler. The accuracy of the profiler both on- and off-machine and its accuracy is compared against similar profilers through its participation in a round robin study. Radius of curvature results are presented for the master spherical segment (MSS), which is a reference optic for the E-ELT segments and highlights a standard deviation on the mean radius of curvature of 2.5 mm. Finally, a summary of future work is presented regarding the polishing of the prototype segments and the development of a stitching algorithm to produce 3D surface maps from profilometry data.

The James Webb Space Telescope (JWST) Primary Mirror Segment Assembly (PMSA) was required to meet NASA Technology Readiness Level (TRL) 06 requirements in the summer of 2006. These TRL06 requirements included verifying all mirror technology systems level readiness in simulated end-to-end operating conditions. In order to support the aggressive development and technology readiness schedule for the JWST Primary Mirror Segment Assembly (PMSA), a novel approach was implemented to verify the nanometer surface figure distortion effects on an in-process non-polished beryllium mirror surface. At the time that the TRL06 requirements needed to be met, a polished mirror segment had not yet been produced that could have utilized the baselined interferometric optical test station. The only JWST mirror segment available was a finished machined segment with an acid-etched optical surface. Therefore an Electronic Speckle Pattern Interferometer (ESPI) was used in coordination with additional metrology techniques to perform interferometric level optical testing on a non-optical surface. An accelerated, rigorous certification program was quickly developed for the ESPI to be used with the unfinished optical surface of the primary mirror segment. The ESPI was quickly implemented into the PMSA test program and optical testing was very successful in quantifying the nanometer level surface figure deformation changes in the PMSA due to assembly, thermal cycling, vibration, and acoustic testing. As a result of the successful testing, the PMSA passed all NASA TRL06 readiness requirements.

The James Webb Space Telescope (JWST) Secondary Mirror Assembly (SMA) is a circular 740mm diameter beryllium convex hyperboloid that has a 23.5nm-RMS (λ/27 RMS) on-orbit surface figure error requirement. The radius of curvature of the SMA is 1778.913mm±0.45mm and has a conic constant of -1.6598±0.0005. The on-orbit operating temperature of the JWST SMA is 22.5K. Ball Aerospace & Technologies Corp. (BATC) is under contract to Northrop Grumman Aerospace Systems (NGAS) to fabricate, assemble, and test the JWST SMA to its on-orbit requirements including the optical testing of the SMA at its cryogenic operating temperature. BATC has fabricated and tested an Aspheric Test Plate Lens (ATPL) that is an 870mm diameter fused silica lens used as the Fizeau optical reference in the ambient and cryogenic optical testing of the JWST Secondary Mirror Assembly (SMA). As the optical reference for the SMA optical test, the concave optical surface of the ATPL is required to be verified at the same 20K temperature range required for the SMA. In order to meet this objective, a state-of-the-art helium cryogenic testing facility was developed to support the optical testing requirements of a number of the JWST optical testing needs, including the ATPL and SMA. With the implementation of this cryogenic testing facility, the ATPL was successfully cryogenically tested and performed to less than 10nm-RMS (λ/63 RMS) surface figure uncertainty levels for proper reference backout during the SMA optical testing program.

The James Webb Space Telescope (JWST) primary mirror is 6.6 m in diameter and consists of 18 hexagonal mirror segments each approximately 1.5 m point-to-point. Each primary mirror segment assembly (PMSA) is constructed from a lightweight beryllium substrate with both a radius-of-curvature actuation system and a six degree-of-freedom hexapod actuation system. With the JWST being a near to mid-infrared observatory, the nominal operational temperature of a PMSA is 45 K. Each PMSA must be optically tested at 45 K twice, first to measure the change in the surface figure & radius-of-curvature between ambient & cryogenic temperatures and then to verify performance at cryo following final polishing. This testing is conducted at Marshall Space Flight Center's (MSFC's) X-Ray & Cryogenic Facility (XRCF). The chamber & metrology system can accommodate up to six PMSAs per cryo test. This paper will describe the optical metrology system used during PMSA cryogenic testing. This system evolved from systems used during the JWST mirror technology development program. The main components include a high-speed interferometer, a computer-generated holographic null, an absolute distance meter, a tiltable window, and an imaging system for alignment. The optical metrology system is used to measure surface figure error, radius-of-curvature, conic constant, prescription alignment, clear aperture, and the range & resolution of the PMSA actuation systems.

In the field of applied optics, the evaluation of imaging quality in optical systems has been a problem of public attention. From the 1970s, with the development of the large-capacity high-speed digital computer and improvement of high-precision optical testing technology, the calculations and measurements of MTF are maturing and began to promote the practical application. After years of development, The MTF has been an important evaluating indicator of image quality of an optical system. A test system of MTF is designed in the paper; theoretical study related to the MTF testing is introduced, such as specifying the physics concept of MTF, summarizing the testing methods of MTF and analyzing the testing principle. On the base of introducing the theory which are related, the framework of system has been established. The devices which are used in the experiment are also introduced. Testing software has been developed. How to manipulate the testing system is introduced and the factors which affect the result are pointed out. The experiment is carried out to measure the optical lens sample in the axis, and the result is given.

Large aspheric optical mirrors and lens are wildly used in high-tech industry such as huge telescopes and synchrotron radiation facilities. The measurement uncertainty of the surfaces is needed to be under several tens of nanometers. Current methods such as interferometry method are not available for measuring aspheric surface with departure over hundreds of wavelength. In this paper, we proposed a new method called improved 3D deflectometry method. Rotatable optical devices are applied to enlarge the measuring range of autocollimator with highly accuracy but small measuring range. Data processing methods are also proposed to improve the measurement uncertainty. Experimental setup is designed based on proposed method. Spherical concave mirror with curvature radius of 5000 mm is measured successfully. The repeatability (mean standard deviation) of 10 times measurement is less than 10 nanometers.

Precision glass molding is the technology of choice for the production of complex-shaped optical components. Protective coatings can significantly extend the lifetime of the molding tools, but the coating properties have to be exactly customized for the individual application conditions, or else an improvement in the tool performance cannot be guaranteed. The currently biggest challenge is to ensure the reliability of newly developed coatings without resorting to extensive and expensive practical testing. However, the usual coating qualification methods either cannot be used or don't provide meaningful results. In this work a new three-tier, application-specific methodology for the qualification such coatings is presented.

Electroless Nickel (ENi) and binderless Tungsten Carbide (WC) are materials widely used in industry to make replication moulds for precision optics, with applications ranging from consumer camera lenses to high accuracy X-ray mirrors. The aspheric shape generation is generally performed by diamond turning in the case of Nickel, and micro-grinding in the case of Tungsten Carbide. However, both machining methods fall short from meeting the ultra-precision criteria required by an increasing number of applications, because of insufficient form accuracy and the frequency content of the machining marks they leave on the surface. It is thus commonly observed in industry that moulds need to be subsequently polished by hand, a usually slow and human resource intensive operation. The Zeeko 7-axis CNC machine, equipped with sub-aperture fluid jet and precessed bonnet polishing technology, has been used to develop deterministic finishing processes on both Electroless Nickel and Tungsten Carbide. Corrective polishing to less than λ/20 (<31nm PV) form error can be achieved, as well as the ability to smooth surface texture down to 1nm Ra or less, in a time efficient manner.

HERSCHEL and GAIA are two cornerstone missions of ESA which embark 3-meter class optics. These instruments require so high thermal and mechanical stability than the SiC technology turned out to be indispensable. The BOOSTEC SiC material has been selected first for its high specific stiffness and thermal stability. But it also shows a perfect isotropy of all its physical properties and it is remarkably more stable than the glass-ceramics in time and also against space radiations. This SiC material has furthermore been fully qualified for application at cryogenic temperature (HERSCHEL and also JWST NIRSpec). The BOOSTEC manufacturing technology of very large size SiC components includes i) manufacturing 1.5 - meter class monolithic sintered parts and then ii) assembly based on a brazing process. The former one is a near net shaping process which allows manufacturing at reasonable costs and within short time. HERSCHEL has been successfully operating at Lagrange L2 point since mid of 2009, giving amazing information to astronomers. It includes a 3.5 m primary mirror, a secondary mirror and a hexapod. It weighs only 315 kg and its WFE is kept below 6 μm rms despite an operating temperature of 80 K. GAIA is made of more than 280 SiC parts of 80 different types. The most challenging of them is undoubtedly its highly stable structure, the 3 meters torus. This quasi octagonal and hollow shaped ring is made of 19 SiC elements brazed together. It weighs only 200 kg. All the GAIA hardware has been successfully manufactured and it is now being integrated and tested at ASTRIUM facilities.

Swing arm optical CMM (SOC), a profilometer with distance measuring interferometric probe for in situ measurement of the topography of aspheric has been used for measuring highly aspheric mirrors with a performance rivaling full aperture interferometric tests. Recently, we implemented a dual probe self calibration mode for the SOC. Data from the dual probes can be used to calibrate the swing-arm air bearing errors since both probes see the same bearing errors while measuring different portions of the test surface. Bearing errors are reconstructed from the shear signal with a modal estimation.

Optical manufacturers often have to deal with a specification on the total integrated scatter (TIS) or "Haze" from a given mirror surface. It is frequently thought that TIS or BRDF measurements are required to assure compliance with these specifications. TIS is determined by the spatial frequency banded-limited "relevant" rms surface roughness, the wavelength of light and the angle of incidence. For short-wavelength (EUV/X-ray) applications, even state-of-the-art optical surfaces can scatter a significant fraction of the total reflected light. In this paper we show that the TIS can be accurately predicted, even for moderately rough surfaces, directly from the surface metrology data. We present parametric plots of the TIS for optical surfaces with arbitrary roughness, surface correlation widths and incident angles. Surfaces with both Gaussian and ABC or K-correlation power spectral density (PSD) functions have been modeled. These parametric TIS predictions provide insight and understanding regarding optical fabrication tolerances necessary to satisfy specific optical performance requirements.

This paper describes recent research into developing an extended range dynamic interferometry technique where the range is extended vertically to enhance surface roughness measurements made in non-ideal environments. Utilizing short pulses from two sources on either side of a frame transfer in a CCD sensor, data can be taken fast enough in noisy shop environments to make measurements in the presence of vibration, and air turbulence. A key application of this technique is monitoring of surface roughness of large optics during the polishing process by making in situ measurements from fine grind through to the final polish. It is anticipated that this monitoring can help speed up what is now a very lengthy process. This same technique is applicable to many other types of measurements including MEMS devices, as it is not affected by dispersion in windows covering devices, and for measuring features on flat panel display glass or semiconductor wafers. This paper describes the technique, and presents results of a variety of sample measurements including: bare glass in various states of polish from fine grind to final polish, scratches and pits in a roughened semiconductor wafer, a DMD MEMS device, and various calibration standards. Performance in terms of repeatabilitity of step heights and roughness for this proof of concept is in the +/-2% range.

Modern precision optical manufacturing places high demands on instrument design, both for flexible response to challenging environments and high lateral resolution for measuring both surface form and mid spatial frequency waviness. Here we report on a Fizeau-type interferometer optimized for light-efficient, single-frame carrier fringe acquisition for instantaneous metrology at high lateral resolution. Fully coherent optics and a 1200 x 1200 pixel camera provide high slope acceptance and an instrument transfer function (ITF) above 50% at 250 cycles/aperture for all zoom settings, as demonstrated for an etched phase step and custom periodic artifact. The instrument further provides an ITF of 500 cycles/aperture using optional temporal phase shifting interferometry on the same platform.

In this study, we proposed an air-driving fluid jet polishing (FJP) system which draws slurry utilizing an air/water mixer. The air-driving FJP system is mainly comprised by an air/water mixer, slurry tank with stirrer, compressed air, pressure and flow rate regulators, and a nozzle. The high speed air flow in the air/water mixer draws out the slurry from the slurry tank, and the slurry is guided to mix with air flow inside the nozzle cavity. Then, the combined fluid slurry is emitted from the nozzle. The air-driving FJP system was preliminarily tested on N-BK7 and ZERODUR® plates with different air pressure and processing time. The test results show that the air-driving system could get a Gaussian-like removal shape with 3 kg/cm² compressed air source and the depth of removal is about 100 nm within 5 seconds processing time. The compressed air improves the kinetic energy of each abrasive, and makes it more efficient in material removal. Furthermore, the Gaussian-like removal shape is more convenient for tool path planning and surface waviness control of corrective polishing.

Previous work on welding of optical materials with ultrashort laser pulses demonstrated that the ability to achieve good contact between components limits the applicability of the technology to only very small components. We have overcome this limitation and demonstrated the capability to weld similar and dissimilar materials using femtosecond laser pulses over several mm² areas between intimately contacted surfaces. Our joining process is realised in two steps. Firstly, the two pieces which must be joined are direct bonded, thereby inducing optical contact throughout the whole potentially bondable surface. Subsequently, the direct bond is reinforced by the inscription of femtosecond laser weld seams in a sealing pattern in order to enclose the central region of the direct bond. We demonstrated the applicability of this process to identical glass, dissimilar glass and glass-semiconductor. We also measured a mean threefold increase in joint strength for such bonds between fused silica windows with only a few welding seams. The final assembly is free from macroscopic surface deformations. Furthermore, by optimizing the laser exposure parameters, we can avoid microscopic defects inside and around weld seams. Finally, the bonding method does not alter the optical transmission properties at the center of the sealed region. As opposed to the use of adhesives, such bonds resist to important thermal constraints and are free from chemical contaminants, degassing and ageing. Potential applications may be considered in the fields of aerospace, laser manufacturing, semiconductor industry, solar cell protection, precision manufacturing and many more.

The VIBE™ process is a full-aperture, conformal polishing process incorporating high frequency and random motion designed to rapidly remove sub-surface damage in a VIBE pre-polish step and eliminate mid-spatial frequency (MSF) errors in a VIBE finishing step. The VIBE process has potential to be introduced in two areas of today's modern optics manufacturing process. The first instance is replacing the conventional pre-polishing step with the rapid VIBE pre-polish step. Results will be discussed in this paper that show 10 - 50x higher removal rates compared to conventional polishing for a variety of optical materials. High removal rates combined with the compliant lap results in damage-free surfaces that have the same form that was generated by the CNC generation process for spherical and non-spherical surfaces. The second potential area to incorporate VIBE into today's modern optics manufacturing process is as a finishing step after deterministic sub-aperture polishing to remove mid-spatial frequency errors. By selectively altering the compliant properties of the VIBE pad, and adjusting the frequency of the VIBE motion, VIBE finishing can reduce the mid-spatial frequencies caused from sub-aperture polishing processes while maintaining the desired corrected surface form. This paper will serve as an in-depth review of the VIBE process and how it complements other modern CNC optics manufacturing technologies, as well as highlighting recent VIBE advances specifically in the area of conformal optic fabrication.

The successful fabrication of several freeform optical elements by ultraprecision micromilling is presented in this article. We discuss in detail the generation of the tool paths using different variations of a computer-aided manufacturing (CAM) process. Following a classical CAM approach, a reflective beam shaper was fabricated. The approach is based on a solid model calculated by optical design software. As no analytical description of the surface is needed, this procedure is the most general solution for the programming of the tool paths. A second approach is based on the same design data. But instead of a solid model, a higher order polynomial was fitted to the data using computational methods. Taking advantage of the direct programming capabilities of state-of-the-art computerized numerical control units, the mathematics to calculate the polynomial based tool paths on-the-fly during the machining process are implemented in a highly flexible CNC code. As another example for this programming method, the fabrication of a biconic lens from a closed analytical description directly derived from the optical design is shown. We provide details about the different programming methods and the fabrication processes as well as the results of characterizations concerning surface quality and shape accuracy of the freeform optical elements.

Precision optical surfaces can be efficiently manufactured using a computer-controlled optical surfacing (CCOS) process. Most CCOS processes are based on control of the dwell time of a tool on the workpiece, according to the desired removal and the tool influence function (TIF), which is the material wear function of the tool. Several major topics were investigated to improve current CCOS processes and provide new solutions for the next generation of CCOS processes. A rigid conformal (RC) lap using a visco-elastic non-Newtonian medium was invented. It conforms to the aspheric surface shape, yet maintains stiffness on short time scales to provide natural smoothing. The smoothing removes mid- to high-frequency errors while controlled dwell time removes low-frequency errors. A parametric smoothing model was also introduced to predict the smoothing effects. A parametric edge TIF model to represent measured edge TIFs was developed and demonstrated. This model covers the removal behavior as the tool overhangs the edge of the workpiece. These new tools and models were applied in a new process optimization technique called nonsequential optimization. The non-sequential approach performs a comprehensive optimization of dwell time using multiple TIFs (multiple tools) simultaneously. An overview of these newly implemented CCOS features** is presented along with some actual CCOS results.

Axisymmetric optical components such as lenses are frequently centered with the use of rotary air bearings, guided by optical instrumentation that use reflected or transmitted light. This report systematically explores methods of adjusting optical elements including wedged-shims, fine pitch screws, and positioning rods with a goal of defining the accuracy that can be expected. Analysis of the performance is supported with experimental data. A characterization and discussion of the merits of each positioning method is additionally presented.

Three ultra-precision machining processes namely fast tool servo, slow tool servo and diamond milling, are frequently used to produce optical freeform surface. Slow tool servo machining has the advantages of no extra attachment and fast setting-up, however the three dimensional tool shape compensation and tool-path generation must be conducted carefully for getting high form accuracy and fine surface finish. This research aimed to develop a model of three dimensional tool shape compensation for generating 3D tool path in slow tool servo diamond turning of asymmetrically toric surface for astigmatic contact lens. The form accuracy of freeform surface was measured by ultra-high accuracy 3D profilometer (UA3P) with user define function. After correction, the form error is less than 0.5μm both in X- and Y-direction and the surface roughness is less than 5nm.

The high filling factor double side micro lens array (MLA) for laser beam shaping has been widely applied in optoelectrical applications. In this paper, we demonstrated the double side MLA for the laser beam shaping process. The point laser source has been successfully transformed into a two dimension uniformity light imaging. The ultra-precision slow tool servo (STS) diamond shaping and plastic injection method for MLA fabrication had been studied. The complexity micro structure of high filling factor MLA via the planning of cutting tool path is used in this research. The high alignment accuracy of both sides MLA is obtained by artful fixture design. The form accuracy and surface roughness are less than 0.1μm and 10nm, respectively. The alignment error of both sides MLA is less than 10μm.

Authors introduce several results of high quality mirror segments testing. The segments were designed for the large-area light-weight mirror systems for UV detectors of weak optical signals. For this category of the optical components, an increasing of demands on technology production is typical. This is caused by various reasons: 1) Thickness to diameter ratio is 1:100 for this type of segments. For astronomical mirrors, this ratio is about 1:10. This is the reason why the manufacturing technology of the light-weight segment surfaces was changed. Similarly, usually used testing methods of the shape of the optical surfaces are changed. The shapes of the surfaces are evaluated by the minimal spot diameter of the reflected beam, which contains 95% of the incident light; 2) Processing technology of working surfaces was enhanced because of the UV light wavelength. The technology must respect the fact that the amount of diffused light in the short UV wavelength region is increasing in the dependence on the surface roughness of the mirror; 3) Surface reflectivity is not the only important parameter of the optical reflecting thin film systems in this kind of applications. Surface roughness and homogeneity of thin films are taken into account of testing methods too.

Extended depth of field (EDoF) technology can be applied to imaging systems by merging phase-coding design and digital signal processing. This paper presents an application of EDoF to the microscope platform and shows the capability to capture EDoF images in a single shot. Ultra-precision machining conditions for a phase-coding component were compared the peak-to-valley (P-V) error of the cubic surface with the performance of the EDoF. For the phase variation is very small for this phase plate, determining the optimal cutting condition at which the quality of phase plate is stabilized is very important. Therefore, the single point diamond turning (SPDT) was used to manufacture the optical components for its high precision. And the results are as following, the accuracy of non-symmetric phase plate found between 0.4 μm and 1μm had better performance of the EDoF image. Overall, the depth of field of the new objective could be increased more than five times compared to an objective having no such phase plate. The purpose of this study is to compare the relationship between PV error of phase plate surface and imaging restoration quality, which maybe a good benchmark in this field.

In this paper we propose an intuitive concept for manufacturing and inspecting of aspherical components. Two types, parabolic and cylinder, of plano-convex and plano-concave aspherical lenses were made by LOH 120S form generation machine. Three form error measurement methods were used known as coordinate measuring machine (CMM), interferometer with CGH null lens and inspection with combined pair lenses. Ultra high accuracy CMM from Panasonic Co., CGH cylinder null and CGH aspheric null from Diffraction International and OWI 150 ASPH CGH interferometer from OptoTech GmbH play the roll for measurement. CMM was used as a surface profiler to inspect the surface shape, and the software GRAPHER was also used as analysis tool to exam asphere numerical datum. The difference between theoretical and practical is as a surface polishing revised reference. The finished plano-convex and plano-concave aspherical lenses can be combined to be a plane lens. The individual and combined lenses were inspected on OPTOTECH OWI 150 ASPH CGH interferometer. The compared interference patterns have shown with the Diffration International CGH Aspheric Null "ASPHERIC 1" and CGH Cylinder Null "H80F2C". Through the procedure, the combined plano-convex and plano-concave aspherical lenses should be a perfect match plane lens and the individual lens might be an aspherical test standard element for quick inspection.

For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision and large lens holders (Ø170 mm) at cryogenic temperatures (120K - 150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that are mounted in a separate lens barrel design. Each lens has its separate mechanical interface to the lens barrel, the so called adaption ring. The performance of the lens holder design shall be verified by an adapted test facility including an optical metrology system. The characterization of the lens deformation and displacement due to thermally induced loads are driven by the required micrometer precision range and by the operational thermal condition. The surface deformation of the lens and its holder is verified by interferometric measurements, while tilt and position accuracy are measured by fiber based distance sensors. The applied distance measurement sensors have the capability to measure in a few mm range with submicron resolution at ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance; therefore the sensors shall be mounted on a stiff and well characterized reference structure made of nearly zero-CTE ceramic material. The verification program is currently under development at Kayser-Threde in the context of a contract with Max-Planck-Institute for Extraterrestrial Physics. The paper presents the vacuum chamber design, the metrology system, the used Ground Support Equipment, and the detailed verification program.

For the ESO Very Large Telescope, TNO is making four Optical Tube Assemblies for the Four Laser Guide Star Facility. Each OTA is a large 20x Galilean beam expander, which expands a Ø15 mm, 25W CW 589 nm input laser beam to a steerable Ø300 mm output. The L2 lens is a Ø380 conical convex lens with a radius of curvature of 637 mm and conic constant k = -0.4776. This paper describes the flexible manufacturing technique that TNO applies to make these kind of optics. With the combination of deterministic polishing and the NANOMEFOS measurement machine, these optics can be manufactured quickly and efficiently, without the need for a dedicated test setup. Final performance testing of the OTA validates all the intermediate steps in the flexible process value chain.

For an optical surface to be properly prepared, the amount of material removed during polishing must be greater than the volume of grinding damage. An intermediate stage between loose abrasive grinding and polishing can reduce the total volume of subsurface damage. This results in less time and expense needed during the polishing phase. We have characterized the Prestos's coefficient and subsurface damage depth for 3M Trizact™ diamond tile pads and believe it can fit this intermediary role. Trizact shows a sizeable reduction in the overall subsurface damage compared to similar sized loose abrasives. This understanding of the abrasive behavior allows us to create a better grinding schedule that more efficiently removes material and finishing with less overall damage than traditional loose abrasives.

We report on optical contacting or "direct bonding" of glass to glass for optical and precision engineering applications. Fused silica (SiO2) and ultra-low-expansion (ULE) glass materials with low and extremely low coefficients of thermal expansion, respectively, were investigated. Large glass wafers of up to 150 mm diameter and about 1.5 mm thickness were bonded to each other and to plane glass substrates of up to 20 mm thickness. Successful bonding was achieved after extensive chemical cleaning and low pressure plasma surface activation, using a commercial wafer bonding equipment. High quality (optically transparent) bonds with a very low fraction of aerial defects were obtained at low bonding temperatures of about 250 °C, by applying compressive forces of several tens of kN in a high vacuum environment. Typically, only small unbound locations occurred at the rim, where insufficient pressure had been applied in the bonding process. Bonding strengths were estimated from destructive "razor-blade" testing of bonded wafer pairs, resulting in bond energies up to about 2 J/m². For surface activation, Nitrogen-plasma was tested in comparison to Oxygen-Plasma without significant differences. However, ULE wafers were found to bond much stronger than fused silica wafers under nominally identical bonding conditions. An exemplary "sandwich" structure was generated from ULE materials by bonding wafers from both sides to a core structure, obtained by perforating a massive plane plate with bore holes. This illustrates possible use in light-weight and stiff construction for high precision opto-mechanical applications.

Although Microcavities are promising in a variety of novel devices, there is slow development in microcavity based practical devices due to the lack of the package technology. In this paper, for the first time, we demonstrate the package technology for the microcavity coupling system to promote the development of the microcavity based practical applications. The package process are illustrated in detail. The changes which result from the package are also discussed. In addition, the advantages of the packaged structure are characterized, including the Q maintenance, robustness and the convenience. These advantages make this packaged structure promising in microcavity based practical devices.

The results of investigation of the phenomena ISPh was reported. It was shown that in the given layers after the irradiation of the polarized light with wave-length actinic for the given sensitizer and of the following specific development the photo-induced anisotropy was visualized. It turns out that weakly expressed anisotropy of the latent image multiplied more than on the two order of magnitude. As it was shown in this investigation, the value of the photo anisotropic parameters can changed in wide-ranging after the specific physicochemical treatment: hypersensitizing, specific worked out developers, thermal treatment, fixing (in case of need). Each of the procedure has such essential value, that the separated examination was needed. For example, 20 developing agent per se and large quantity of the different compositions, and also the quantity hypersensitizers was investigated. The photo induced anisotropy maybe measured on the modified spectrophotometers SF-10 or SF-18. To receive experimentally the dependence of the anisotropic absorption, and the light induced birefringence it is necessary to carry out not less than 6 measurements of transmission of the differently oriented irradiated samples (0°; 45°; 90°), placed between parallel and crossed polarizers in the spectrophotometer. Some technological regimes which reduced to the optimization of the parameters of the photo anisotropy are presented. The high stability, the possibility of working in the red region and with the low power energy sources, with the wide controlled characteristics are represented the main advantage of such media. In addition the Schwarzchild effect in the ISPh phenomena is considered.

New stable polarization-sensitive materials are developed on the hydrophobic components basis which doesn't require an additional moisture protection. Bisazodye ortho-tolidinebisazophenol chromophoric component was synthesized which is liposoluble analogue of water-soluble azodye Mordant Pure Yellow M. This bisazodye were used to develop the hydrophobic materials films which can be applied as a protective layer themselves. To increase the thermal stability we have synthesized material by introducing bisazodye into the main-chain of macromolecule of thermally stable polymer. The different types of polarization-holographic gratings with high diffraction efficiency of 30-50% were recorded on the obtained materials by laser beams (441 - 488 nm).