This PDF file contains the front matter associated with SPIE Proceedings Volume 10314, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

Recently, micro aspherical glass lenses are required for electric devices, optical devices and advanced optical fiber transmission equipments. The glass lenses are manufactured with glass molding method by using ceramics dies such as tungsten carbide and therefore molding dies are most important. The ceramics molding dies must be ground ultra-precisely with micro diamond wheel. In this report, our developed micro grinding methods/systems are discussed according to a variety of the workpiece shapes.

To realize high-precision glass molding, some themes are yet to be settled, including performance of molding machine, molding conditions, material and accuracy of molds. To get a desired product profile with predetermined accuracy, molds must be manufactured according to specified accuracy. The present molding machine has a high transferability of fine profile, but causes minor difference in profiles by thermal expansion and contraction of mold and glass material as it involves a heating process. We clarify the results of experiment and verification of the two methods , in consideration of a heat expansion difference, molds is manufactured beforehand and feedback of geometrical error of prototype mold product to mold profile.

Summary This paper provides a progress-report on the development of the Precessions polishing process. This is a new small-tool polishing technique for producing aspheric forms and correcting spherical forms. Precessions polishing has been developed by Zeeko Ltd in collaboration with the Optical Science Laboratory at University College London and Loh Optikmaschinen. The Zeeko/Loh All machine (see figure below) has a capacity of 200mm diameter, and is targeted at industrial lenses and mirrors. The baseline of the PrecessionsTM process is a sub-diameter physical tool working the surface with a polishing slurry. Position and orientation of the tooling is controlled by a 7-axis CNC polishing machine that has been custom-designed for the purpose. The tool comprises an inflated, bulged, rubber-membrane (the 'bonnet'), covered with one of the usual proprietary flexible polishing surfaces familiar to opticians. The membrane moulds itself around the local asphere, keeping good contact everywhere. It is spun about its axis to give high removal-rates, and attacks the surface of the part working on the side of the bulged surface, rather than the classical pole-down configuration. The contact area and polishing pressure can be varied independently by changing the degree to which the bonnet is compressed, and the internal fluid pressure. The rotation axis is precessed around the local normal to the part, and this averages surface texture and achieves a near-Gaussian tool removal-profile (Influence function'). For axially-symmetric parts, the part is rotated and the tool moved radially, thereby creating a spiral tool-path. An off- line software application analyses i) the surface error-profile, and ii) experimental data on the tool influence functions for different spot-sizes. An iterative numerical optimisation method is then used to compute the dwell-time and spot- size for each zone of the spiral on the surface, to rectify the form error.

A small distinction of some micron makes an awful difference between spheres and aspheres. It takes special technological equipment to manufacture and test aspheric optics. This equipment is clearly distinguished from that for classical optics manufacturing. This paper deals with equipment installed at JENOPTIK L.O.S. and give results based on serial manufacturing of aspheres.

The high-precision grinding technology is making contribution in every field, which is especially remarkable in the optics-related field. Lenses for digital camera and projector, which are mass-produced, for instance, are molded by the injection molding machine and glass molding-press machine. Concerning materials of high-precision molds, nickel alloy is mainly used in plastic-molding. And brittle material such as tungsten carbide and ceramic is used in glass-molding because the molding temperature is generally high. High-precision machining of nickel alloy is possible with a single-crystal diamond tool. Brittle material is ground by means of a diamond wheel, etc.

Wet etch figuring (WEF) utilizes surface tension gradients to confine and stabilize the footprint of an etchant solution contacting an optic, and uses real-time optical interferometry for closed-loop control the local dwell time of etchant on the optic. This enables precision figuring of arbitrary continuous contour optical shapes with gradients of up to 0.5 waves/ mm. This stress-free figuring method enables the figuring of ultrathin optics, and allows inexpensive thin sheet glass to become raw material for precision optics such as phase plates, aberration correctors and beam shapers. We present data on surfaces generated and discuss surface smoothness of optics manufactured by WEF.

Presently aspheric glass surfaces for the optical industry getting more and more important to reach the high demands on optical systems and designs. Still there is a limitation in polishing of especially complex structures and freeforms by mechanical methods with regard to process time and therefore economic efficiency. In the research activities a thermal polishing process for smoothing optical glasses is developed. It is the goal to polish mainly asperic lenses and other micro-machined structures on glass substrates. Due to the sensitivity of thermal stresses of glasses the glass body has to be heated for reduction of the thermal gradient in order to use a CO3-Laser for polishing the surface. The basic investigations using this combination of processes show the feasibility of thermal polishing. Further process development and advantageous laser beam guidance will show the polishing of complex surface structures.

In support of the Constellation X mission the Optics Branch at Goddard Space Flight Center is developing technology for precision figuring and polishing of mandrels used to produce replicated mirrors that will be used in X-Ray telescopes. Employing a specially built machine controlled in 2 axes by a computer, we are doing automated polishing/figuring of 15 cm long, 20 cm diameter cylindrical, conical and Wolter mandrels. A battery of tests allow us to fully characterize all important aspects of the mandrels, including surface figure and finish, mid-frequency errors, diameters and cone angle. Parts are currently being produced with surface roughnesses at the 0.4nm RMS level, and half-power diameter 0.6 arcseconds.

Deterministic micorgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-51.tm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an OptiproTM CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Chatter is one of the most critical errors in grinding since it can both degrade the surface quality and reduce productivity. In this paper a model for regenerative chatter during the contour grinding of optical surfaces is developed. In this model, a nonlinear formula for projected contact area is used to derive the process cutting stiffness that predicts the occurrence of chatter. Experimental results show how chatter can be minimized by properly selecting the process parameters.

Summary The PrecessionsTM process, and the 200mm capacity 'All' machine which embodies it, are outlined in the accompanying paper 'New method to control form and texture on industrially-sized lenses'. In this paper, we summarise the development of the process to address larger optical components. The first machines constructed for this application are of 600mm capacity. A conceptual design of a 1-2m class machine of bridge- configuration has also been produced. Unlike the All machine, the work-piece on these larger machines lies in a horizontal plane i.e. with the rotation axis of the work-piece spindle vertical. This configuration is preferred because it allows the use of a hydrostatic support-system for the work-piece; important for large optics in general, and particularly so for light-weight optics. The machine can also provide a clear vertical path above the work-piece for optical testing, or for access by lifting gear. It is interesting to consider how the PrecessionsTM process can be scaled. As an example, consider first that the type of surface-form remains the same; it might, for example, be an f/2 parabola. Consider then that the work-piece diameter, the bonnet-diameter, the polishing spot-sizes used, and the tool-path on the surface, are all stretched by a factor of two. The area of the polishing spot and that of the work-piece have both increased by a factor of 4, but the number of convolutions of the spiral tool-path remains the same. Since the spot instantaneously addresses the same fraction of the overall work-piece surface-area, the terms all cancels in relation to cycle-time. However, for the same tool-rpm, the larger bonnet delivers a proportionally higher surface-speed, because the polishing action is further from the axis of rotation. Therefore, the volumetric removal rate (proportional to contact-area times surface-speed) tends to vary as the cube rather than the square of the scale-factor. As a result, the larger bonnet working over the larger work-piece with the same polishing pressure, will remove twice the depth of material in the same time. The above scaling could, in principle, reduce cycle times on larger parts. In practice, we have found that excessive removal-rates lead to impractically short dwell-times, especially near the centre of a spiral tool-path. Such scaling also demands increased traverse-speeds and accelerations from the machine, and this rapidly becomes a limitation. Moreover, as the process converges on final form, smaller depths of material need to be removed. In practice, we have found it necessary to moderate the process by diluting the slurry and by moving from a polyurethane tool-surface to a material that delivers a lower-removal rate, such as Multitex. We are also developing bonnets that are compatible with operation at a reduced polishing pressure, in order to give additional control for fine-removal. The current status of the process development is as follows. A form error of -80nm peak-to-valley has been achieved aspherising a 100mm diameter part. This work revealed some subtle but significant limitations in the optimisation code, mostly concerned with convergence and residual ripples. Recent work has focussed on this aspect, and the revised code is now ready for polishing trials. A 150mm diameter part is currently in-process, and work is about to commence on a 300mm fused silica mirror for a space application.

Lapping is an important dimensioning and finishing technology that is used in many different industries including metal, electronic, and optical component fabrication, as well as silicon wafer production. In each of these applications lapping is used to produce flat substrates of a controlled thickness, flatness, and surface roughness. Lapping can be performed in either a single -sided or double -sided operation! Conventional lapping technology can be divided into two basic categories: loose abrasive grinding (slurry lapping) or fixed abrasive lapping. In slurry lapping the abrasive is in the form of an aqueous slurry of abrasive minerals (typically alumina or silicon carbide) and the lapping surface is the machine platen (typically cast iron).1 Conventional fixed abrasive lapping is also called "pellet lapping. In this process the abrasive (typically diamond) is incorporated into small pellets (metal, vitreous, or resin bond) which are attached to cast iron machine platens. The lapping surface during pellet lapping is formed by the top surfaces of all of the pellets. Here we report on a structured abrasive lapping technology developed by 3M. The structured abrasive pad consists of an organic (polymeric binder) - inorganic (abrasive mineral, i.e., diamond) composite and is used with coolant. Typical lapping coolants including deionized water are used as lubricants without the addition of any free abrasive mineral. Table 1 shows a comparison between conventional loose abrasive, pellet, and 3M fixed abrasive lapping technology.

The 3D nano-machining and measuring system that can control with nanometer-scale accuracy have been developed in this research. In this system, the functions of position control and NC have been expanded based on surface observation function of friction force microscope (FFM). Precision positioning of cantilever was possible by using the displacement sensor in this system. Newly machining cantilever' with high stiffness was developed, and spinous single diamond grain was bonded on the end of this cantilever. Cantilevers for machining and measuring were able to exchange alternately. By using this system, 3D nano-machining and measuring was achieved.

A fluid jet apparatus for possible glass polishing application was constructed. The apparatus is capable of producing abrasive jets with a velocity of approximately 40 meters per second and has been used to test the effects of an abrasive slurry on a flat, glass surface. The slurry's exit velocity is controllable by changing the nozzle diameter. After testing multiple samples at each of three velocities used, each sample was analyzed and depth profiles were taken. From these profiles, characteristics such as maximum depth and diameter were used to calculate the material removal rate. Using these results, the effects of the differing velocities were compared. A strong increase in material removal rate with the average velocity was found. Analysis of the depth profiles showed that at the lowest velocity tested (27 m/s) the glass appeared to be deformed rather than removed. Much clearer fluid jet spots were produced at higher velocities. As expected, the highest velocity used in this test (produced by an 18 gage nozzle) removed the most material and yielded the clearest depth profiles, but also suffered from trouble with particle agglomeration due to the nozzle's small diameter

A new multiwire Fixed Abrasive Slicing Technology (FAST) was developed that combines the low kerf loss and high material utilization of multiwire slicing (MWS), low consumable costs of internal diameter (ID) slicing and low cost of multiblade slicing (MBS) technologies. Recent improvements in FAST allow it to be utilized for effective slicing of hard materials at low cost. For over two years, 2-inch diameter sapphire has been sliced in prototype mode for supplying wafers to the industry.

In this study, a fine abrasive grinding wheel, called EPD pellet, was fabricated and a silicon wafer was ground with constant pressure machining. Constant pressure grinding with silica EPD pellets made a mirror surface about 3.4 nmRa on the silicon wafers. The highest grinding ratio was about 2.0, twice as much as case of ordinary constant infeed grinding.

A cost effective process for manufacturing of silica glass optical components via sol-gel is presented. The process is characterized by the thermomechanical "quasi-ideal" isotropy of the aerogel and the glass it forms, and by precision molding, at least up to 1/1000, without intrinsic dimensional limitations. The undoped material has at least 85% optical transparency in the whole spectral range from 185 nm up to 3200 nm, the impurities being mainly at the ppb level or below. The glass optical properties can be adjusted by doping. An industrial model and some cost considerations are given.

The optical axis of a spherical lens is the axis passing through the two centers of curvature of the optical surfaces. It is such a simple thing to describe. However, detecting where the axis is and positioning it can be as complex as the definition is simple. Make one or both of the surfaces aspheric and it gets even harder.

During 1997-2002 JSC "LZOS" has fabricated a number of astronomical mirrors under the contracts with Carl Zeiss Jena, Germany such as four primary mirrors with hyperbolic figure of 2050mm (F/3) in diameter and two secondary mirrors of 645mm (F/2.5) in diameter for Telescope Technologies Ltd, UK, primary mirror of 2280mm(F/2.3) and secondary mirror of 753mm (F/2) for NOA telescope (Astronomical Institute - National Observatory of Athens, Greece), primary mirror of 2650mm (F/1.8) and secondary mirror of 938mm (F/2.3) with an asphericity of 1001.tm for the VST telescope (VLT Survey Telescope). We have completed a number of astronomical mirrors with diameters up to 1300mm for some European countries and the USA. The rms surface quality of all of the mirrors was in the range from 9 to l2nm. We used computer controlled figuring, polishing and testing. All mirrors were made of Sitall CO-115M, producing by LZOS, some of them were of Zerodur. Our current projects are manufacturing primary mirror segment blanks for SALT project, figuring and polishing of the LAMOST Mb submirrors.

Plastic optics are often mass produced by injection, compression or injection-compression molding. Optical quality molds can be directly machined in appropriate materials (tool steels, electroless nickel, aluminum, etc.), but much greater cost efficiency can be achieved with electroformed mold inserts. Traditionally, electroforming of optical quality mold inserts has been carried out in nickel, a material much softer than tool steels which, when hardened to 45-50 HRc usually exhibit high wear resistance and long service life (hundreds of thousands of impressions per mold). Because of their low hardness (<20 FIRc), nickel molds can produce only tens of thousands of parts before they are scrapped due to wear or accidental damage. This drawback prevented their wider usage in general plastic and optical mold making.

Magneto-rheological-finishing (MRF) technology is capable of substantially improving the surface figure of spherical lens to about 1/20 wavelength. Nonetheless, since MRF technology is an ultra-fine polishing process, in which only less than a few microns of material will be removed per cycle, time for making an aspheric surface from a best-fit sphere can be very significant. The situation can be worse if the surface profile is considerably deviated from its best-fit spherical surface. This is not desirable for actual production, and thus a manufacturing cell is proposed to enhance the efficiency of the high precision lens manufacturing process. On the other hand, MRF was suggested to be an alternative for lapping of surface of ceramic lens mould insert. Rather than using the abrasive particles in typical lapping process, the magnetized slurry in MRF is moved past the rotating surface of mould insert locally under the computer-control process so as to achieve the desired surface form accuracy.

Magnetorheological finishing (MRF) of a diamond turned poly(methymethacrylate) (PMMA) flat was demonstrated using a commercial Q22Y MRF machine and a zirconia-based magnetorheological (MR) fluid. The surface of a 38mm diameter by 7.6mm thick puck was processed in a sequence of two figure correction runs. The initial p-v wave front error of 4.5[tm was reduced to 0.35 lam, and the average rms surface micro-roughness was reduced from 3.8nm to 0.47nm. The diamond turning marks were eliminated

Spot surface morphology can be considered as a footprint of the removal process in magnetorheological finishing (MRF). When properly processed, it can account for the performance of the MR fluid in polishing. Experiments were done using different conditions to vary removal rate and evaluate the resulting effect on microroughness and the overall spot surface morphology. Such experiments have been performed on two optical glasses, with several different MR fluids and a wide range of machine parameter settings. Atomic force microscope (AFM) measurements show that the surface morphology has a strong dependence on the abrasive type in the MR fluid. Interferometry measurements show that the roughness inside the spot increases with the rate of the material removal.

The strength of silica optical fibers depends on the water activity at the glass surface. Polymer coatings are currently applied to optical fibers to protect them from mechanical damage during handling. They also act as a barrier diffusion of the surrounding humidity reaching the glass surface. Water is known to be one major factor of the propagation of cracks at fiber glass surface because it makes much easier the breaking of the Si-O bonds which build the vitreous network. The strength of the fiber is related to the water concentration at the glass surface. It is well known that flaws in glass subject to stress in humid condition grow subcritically. The crack velocity is related to the applied stress and also to the humidity rate [1]. The kinetic of the reaction between silica and water changed at very low water concentration [2].

We discuss micromechanics contributions to the loose abrasive polishing removal rate in fused silica, and the multicomponent glasses (crown) BK7 and (flint) SF6. Nanoindentation reveals the contributions of hardness at depths in the range 2-6 nm.

Polishing of optical components produces defects in the subsurface resulting in a decrease in their performance. These defects can be large, like cracks, but also punctual, like oxygen vacancies or non bridging bonds. Under electronic excitation, punctual defects can produce luminescence (also called cathodoluminescence) and/or can trap electrical charges. We have developed a new technique for investigating the trapping of charge and the cathodoluminescence in insulators by using a Scanning Electron Microscope (SEM). Then, it is possible to control the depth of electron penetration by changing the electron beam energy. Therefore, we hope that this technique allows measuring the depth profile of subsurface punctual defects due to the polishing. In this work, we have investigated amorphous silica prepared with different surface finishing.

Aluminum oxynitride (ALON) is a material with desirable qualities for a variety of applications that has proven difficult to polish because of its grain structure. Bound abrasives may prove to be an effective means of polishing it, and work is being done with them to obtain good surfaces on ALON, with reasonable removal rates. Laps consisting of abrasives bound in epoxy matrices have been created for polishing ALON. The effects of varying abrasive type, abrasive concentration, lap shape, coolant and load are being studied. Metrology procedures are being developed to monitor different aspects of the grain structure and numerically evaluate its decoration. Strategies have been developed to polish ALON at acceptable rates with reasonably good surface quality. Work is directed toward finding optimal bound abrasive lap formulations that can be fabricated into ring and/or contour tools for testing on CNC machining platforms.

Peak-to-valley surface microroughness measurement data acquired from a white light interferometer are compared with data from the actual depth of subsurface damage (SSD) acquired destructively, in single crystalline optical materials (Si, CaF,, MgF2, LiNbO3, A1203) after deterministic microgrinding (DMG). The results demonstrate that SSD is always less than 1.4 times the peak-to-valley surface microroughness for these crystals regardless of crystallographic orientation. These results enable a maximum depth of SSD to be predicted non-invasively for these single crystal materials. The Center for Optics Manufacturing also has an extensive database comparing surface microroughness to SSD in optical glasses. This data will be presented, demonstrating the upper bound for SSD depth in optical glasses based on the surface microroughness. Interferometer settings and destructive techniques for physically determining SSD will be presented.

Characterization data for five experimental optical polishing pitch products were compared to those for corresponding standard commercial optical polishing pitches. The experimental pitches were tested for three physical properties: hardness, viscosity at 90°C, and softening point. A Shore A Durometerl test was used to measure hardness. Viscosity data were collected using a Stony Brook Scientific' falling needle viscometer. Softening point was determined using the ASTM D3104-97 method. Results demonstrate that the softest and the hardest batches of the experimental grades of optical pitch are comparable to the industry-accepted standards, while the other grades of pitch are not. The experimental methodology followed in this research may allow opticians to rapidly compare different brands of pitch to help identify batch- to- batch differences and control pitch quality before use.

We describe a process for fabricating light weight mirrors from single crystal silicon. The process uses conventional fabrication techniques in an unconventional sequence. The optical surface is ground and polished before light weighting. Distortion is minimized due to the crystalline nature of the material. A final trim polishing step creates no significant print-through due to the small amount of material removed. We are presently completing a set of 4" (10.2cm) diameter test mirrors good to better than 1/10th wave P-V (@633nm) or 1/80th wave RMS. Each mirror is a monolithic structure of single crystal silicon weighing about 80 grams. We are just starting a set of mirrors for the GeoSpec (Geostationary Spectrograph) instrument, including a 10" (25.4cm) diameter, F/3.5 primary.

Low thermal expansion ceramics have been required for ultra precision nanometer positioning stage in the semiconductor equipments. Especially pore-less advanced ceramics have been playing an important part as mirror materials in the optical equipments. Nippon Steel produces Sialon and NEXCERA as the solutions for these demands. Sialon based on silicon nitride shows a thermal expansion of 1.3 x 10-6/K with a high Young's modulus of 300GPa. Newly-developed NEXCERA based on cordierite ceramics shows near-zero thermal expansion around the room temperature with a Young's modulus of 130GPa. For these advanced ceramics, near-net shape sintering, direct bonding and mirror polishing are available. These technologies will provide us new design possibilities in precision engineering fields like optical system.

Increasingly, a finer finish polish is being sought in a variety of technologically advanced glass polishing applications. From the production of photomask blanks to the manufacture of precision lenses and prisms, improvements in surface planarity and the reduction of incidents of defectivity are critical to achieving higher levels of device performance. Nanophase Technologies Corporation (NTC) uses a patented plasma arc synthesis technique to produce nanosized cerium dioxide (ceria) particles. The small particle size, narrow particle size distribution, and unique crystal morphology of this ceria allow new performance benchmarks to be realized in the areas of decreased surface roughness (increased planarity), and reduced residual defects and subsurface damage. However, the success or failure of a nanocrystalline material in a particular application depends on the ability to form and maintain a stable dispersion with controlled rheology. The preparation of stable dispersions of nanocrystalline cerium dioxide particles is discussed with the following performance figures of merit - particle size stability, dispersion settling stability, and the ability to manipulate the isoelectric point and the zeta potential of the particles. Aspects of the dispersion specifically engineered for glass polishing, including pH and rheology characteristics, are presented. To illustrate the application of the nanocrystalline ceria dispersion, a specific example of an integrated program to reduce defects in the manufacture of quartz glass substrates and EUV (Extreme Ultraviolet) mask blanks at Schott Lithotech AG in Meiningen is presented. Substrates made of Low Thermal Expansion Materials (LTEM) require modified process formulations to achieve the flatness, roughness and defectivity goals of EUVL (Extreme Ultraviolet Lithography) mask blanks. Results of these processes for several LTEM options establish direction for material improvements, define key polishing process parameters, and guide the identification of important opportunities for future process adaptations. Results of the low defect polishing process for quartz glass substrates will be reported, along with activities directed toward adapting this process for LTEM substrates.

In this paper we report the experimental study of gain of telecommunication Erbium Doped Fiber Amplifier (EDFA). For particular pump power, the gain of Erbium Doped Fiber Amplifier for the wavelength range of 1529 nm - 1559 nm was measured and found that the gain of the Erbium Doped Fiber Amplifier is very uneven exhibiting peaks with different widths around 1535 nm and 1550 nm . On analysis of the results, filters of desired characteristic is suggested which could support for flattening the gain of EDFA for fixed pump power , so that the EDFA could be used for WDM applications .We have flattened the gain spectrum of a commercial Erbium-doped fiber amplifier, obtaining a curve with approximately ± 1.55dB of ripple, from 1530.1 nm to 1557 nm, using eight fiber bragg gratings as equalizing optical filter.

The state of the art cleanliness of substrate surfaces prior to a coating process is decisive for its success. Any contamination of the surface affects the adhesion of the coating and leads to defects. The degree of cleanliness of the surface can not be expressed in numerical terms and can only be demonstrated by the use of suitable aids. The objective sought is "freedom from residues" and "freedom from particles", as perfectly as possible. Uniform, reproducible quality is indispensable, even when the products supplied from the preceding stages of manufacture vary within relatively wide tolerances in terms of shape, size, nature and degree of contamination. The solution to this type of problem requires well-tried process technologies in user-friendly equipment which operates safely and economically. One well-tried cleaning procedure prior to coating is based on cleaning with aqueous solutions plus ultrasound, followed by drying. In the course of today's increasing awareness of environmental matters, processes which make use of solvents prior to coating have meanwhile disappeared completely from factories. Cleaning in aqueous solutions is carried out in accordance with precise cleaning mechanisms. Cleaning is always a multistage process, in which cleaning and rinsing stages alternate repeatedly. Modern multi-chamber cleaning plants are to be found in the optical and electronics industries and fine mechanics as well as in the high-vacuum coating area. (coated lenses and hard coating)

In the past 10 years improvements in micro-lithography have generated increasing demands on the performance of optical components in lithography machines and inspection devices as well. At this time typically used illumination sources are 248nm and 193nm lasers (KrF and ArF excimer lasers). Systems with 157nm (F2) excimer lasers are in a launching phase. Inspection with 266nm solid state laser (4th harmonic of Nd: YAG) or 193nm excimer laser is getting increasing interest too. First approaches to DUV or VUV coatings were focussed on realising useful windows, output couplers and folding or end mirrors with acceptable high transmission or reflection, respectively. In addition the laser induced damage threshold (LIDT) of the coated elements should be as high as possible when tested in so called 1-on-1 or 1-on-N tests (1 or N high-power laser pulses focussed on one point of an elements surface). After fulfilling these fundamental requirements the elements must meet additional specifications defined also for user-optimised component applications. In detail there are typical demands related to long-term and climatic stability, component lifetime during application, shift behaviour of the optical function, hardness of coating surfaces and resistance against chemical solvents together with a possibility of careful cleaning contaminated surfaces. Also mechanical film stress got more and more interest as a reason for deformation of ultra-precise finished optical surfaces and related wavefront distortions. Furthermore, the optical functions of UV components have become more complicated. Now the DUV and VUV filters, polarisers or attenuators show similar or more sophisticated optical performances compared to those components used for applications in the visible range. In this paper there will be presented some examples for improvements of component properties

The French Commission for Atomic Energy is currently involved in a project which consists of the construction of a 2 MJ/500TW (351-nm) laser, so-called LMJ (Megajoule-class laser) devoted to Inertial Confinement Fusion (ICF) research in France. A prototype facility so-called LIL is used today to qualify the laser architecture. For these high power lasers the sol-gel process has been selected for 95% of laser optical coated area because of room temperature and atmospheric pressure deposition conditions with guarantee for high optical and laser-included damage performances at a low cost compared to conventional vacuum deposition processes,. Today, we have developed a large variety of coatings, such as antireflective, environmental protective, broad-band antireflective, scratch resistant or high reflective coatings for our laser needs. Due to their ability to ensure appropriate deposited optical thickness, room-temperature deposition techniques such as dip-, spin- or laminar-flow-coating have been optimized for laser coating production. Today, 264 components have been successfully coated for the LIL laser needs.. Optical and laser damage characterizations show the produced component performances being in compliance with the high power laser requirements.

Mechanical analysis can be useful in support of optical tests. Comparison of test and analysis improves the understanding and confidence in both. Tools are available to convert finite element (FE) results into a format compatible with interferogram test arrays for easy correlation.

The radius of curvature on a conventional spherical lens is a fundamental parameter. You would think that tolerancing a radius would be as easy as tolerancing the thickness or diameter of a part. In fact, tolerancing and certification of a spherical surface is rather complex.

We present a number of measurement methods that we use in the fabrication of solid LiNbO3 etalons. Several unique technical features, such as high finesse, large aperture/high aspect ratio, and tunability, require careful monitoring of quality parameters throughout the production process. We point out the critical issues and how we monitor them.

The importance of understanding the design and use of Fizeau transmission spheres, for accurate evaluation of surface irregularities, cannot be understated. There are several characteristics that have a significant impact on the interpretation of the resulting data. Specific tests can be performed on a routine basis to quantify and maintain calibration of the precision masters and as a result, errors attributed to the transmission sphere can be isolated. The overall goal is to obtain accurate evaluations of surface irregularities of the actual surface under test.

Incoherent third-harmonic (TH) generation, or hyper-Rayleigh scattering (HRS) on TH was observed for the first time, to our knowledge, from silver island films (SIF). The interpretation of the experimental results is based on the correlation between optical properties and structural features of SIF.

Areal maps of optical retardance are rapidly generated for flat, transmissive optics using a new commercial birefringence mapper. The versatility and capabilities of the mapper are evaluated for a series of parts that include laser glass samples, laser damaged glass, liquid crystal devices, birefringent crystals, and polymers. Potential users may be trained to use the instrument in less than one hour.

Mask substrates for advanced semiconductor microlithography at 157 nm and 13 nm (EUV) require a surface flatness of 50 nm P-V. Production polishing methods require the surface metrology accuracy to be about 1110th this tolerance, or 5nm. Interferometric measurement accuracy is affected by the following factors: fringe pattern from the backside of the plane-parallel substrate, accuracy of the reference flat surface, retrace error of the interferometer optics, and coherent noise (speckle) associated with the coherent source. This paper describes the performance of a new wavelength-shifting Fizeau interferometer that is capable of simultaneously measuring the surface height of the front and back surfaces of an EUVL mask blank substrate to an absolute accuracy of 5 nm and an RMS repeatability of <0.01 nm. Unlike conventional Fizeau interferometers, it can simultaneously measure front surface height, back surface height, and relative thickness of a plane-parallel transparent glass plate while minimizing multi-surface fringe print-through artifacts. Surfaces with substrates as thin as 2 mm can be measured by this instrument, although the technology is readily extendable to thinner substrates. Back side fringe print-through is shown to be in the range of 0.1-0.5 nm P-V. Additional features of this new interferometer include a 300 mm diameter aperture, a set-up configuration suitable for automated part handling, an optical design optimized for low retrace error, a wavelength-tunable AlGaAs laser diode operating at 850 nm, a fiducialized transmission flat surface that is calibrated to 3 nm absolute accuracy, and a spatially incoherent source configuration for low speckle noise performance. Measurement data as well as an accuracy budget are presented.

When fabrication of optical surfaces requires motion of the processed surface, it is useful to make a fast measurement of the roughness parameters such as the standard deviation a and the correlation radius A. This can be performed with the help of two devices, in which the processed surfaces are illuminated by high-energy pulsed laser radiation and their coherent images in diffuse scattered light are analyzed. One of the devices provides determination of the standard deviation a and the correlation radius A. for the processed surface in a fixed domain with an accuracy of 10%; the method is valid for roughness heights larger than 10 nm. The second device provides fast measurement of Cr and A in various domains of the surface. These devices can be used to control 0" and A of a optical surface moving in the process of its fabrication such as, for instance, a surface rotating during its mechanical processing. In particular, this is important for fabricating metal mirrors by metal surface sharpening with the help of diamond-tipped cutting tool.

Subaperture stitching is a well-known technique for extending the effective aperture or dynamic range of phase measuring interferometers. Stitching has been routinely applied to extend the spatial coverage of plano interferometers. Due to the presence of additional mechanical and optical degrees of freedom, it has been much more difficult to apply stitching techniques to spherical and aspherical interferometric testing. Particular care must be taken in mechanical alignment, motion control, and mathematical processing of subaperture phase data in order to obtain an accurate reconstruction of the full-aperture phase map. We have designed and developed an interferometer workstation specifically to perform high-accuracy subaperture stitching of spherical and flat surfaces up to 200 mm (8") in diameter. The workstation combines a commercial 100 mm (4") Fizeau interferometer, a 6-axis stage, and a software package that automates the entire stitching process. Automation of the measurement design, motion control, phase data acquisition, and data analysis process allows complex stitched measurements to be made in a shop-floor production environment by optical technicians of modest skill. Mathematical techniques were developed to compensate for several classes of systematic and random errors inherent in the measurement process, e.g. motion errors, magnification error, viewing system distortion, and reference wave error. This allows each measurement to be self-calibrated. Basic system capability is demonstrated by comparing a conventional full-aperture phase measurement of a surface to a measurement reconstructed from stitched subapertures.

Despite advances in various metrology tools, interferometry remains the method of choice for measurements of optical surfaces. Fizeau interferometers can achieve precisions of X/100 PV (and better) with proper environmental control. The quality of the reference surface, however, usually limits the uncalibrated accuracy to merely X/10 PV or so. Various methods have been developed for "absolute" (unbiased) surface testing, including the N-position, 3- flat, 2-sphere, and random average tests. The basic principle of these tests is that the reference wave error remains invariant when the part is moved. These tests as a rule require multiple parts and/or measurements at different positions. Sub-aperture stitching requires measurements at multiple positions, and thus in principle can measure reference wave error. QED's stitching algorithm exploits this possibility to produce a measurement of the reference surface along with the stitched full-aperture phase. The precision mechanics of QED's stitching workstation make it an excellent platform for performing conventional reference wave calibrations as well. Results obtained from the QED stitching algorithm are compared with other calibration methods performed on the same workstation. The mean results and uncertainties of the various methods are evaluated, and limitations discussed.

UV curing plays an important role in the optical shop for cementing optics or for the fabrication of replicated optics. Material shrinkage is a common but unwanted effect during UV curing, because it causes stress and form modifications. In order to minimize these effects it is useful to measure shrinkage and surface changes that occur during the UV curing process. For replicated optics, shrinkage and form modifications are usually measured by comparing the replica to the mould geometry after the curing process has finished. In this paper, a measuring method is presented, which enables the observation of shrinkage and changes of the surface shape in situ. The surface of UV hardening material, in this case a commercially available optical adhesive, is monitored interferometrically during UV curing. This enables observing the material effects that cause stress and form modifications in real time.

During the lens design process the experienced optical designer will examine the design as it evolves to identify any possibilities of lens simplification that may lead to a more cost effective and reliable final product. In this paper the author describes a recent lens design assignment and presents details of how he applied his background and experience to incorporate a number of these design simplification elements. A series of experiments are scheduled for the year 2005 on board the International Space Station under the direction of the Canadian Space Agency. Among these are a number of experiments where the effects of the space environment on several populations of fruit flies will be observed. These observations will be made, not only on board the Space Station, but also remotely via a video link to numerous scientists here on earth. In order to accomplish this remote link, a high quality video camera will need to be an integral part of each insect habitat module.

Many changes have occurred in business strategies for precision optics manufacturing. The author reacts to two papers published by D. Reid, R. DeMartino, and S. Zyglidopoulous. titled "An Emerging Photonics Industry: The. success Vulnerability Paradigm' and "New Business Creation and Technology Transfer in the Rochester Cluster'''.

Lens centering is a very traditional area. The question is how is to make a sophisticated robot? It has to detect the centering errors and to adjust the lenses in accordance to a well defined axis. There are four ideas for lens centering: adjustment by joining, by circular milling, by fast and slow turning.

MOTIVATION Ongoing miniaturisation and higher requirements within optical assemblies and the processing of temperature sensitive components demands for innovative selective joining techniques. So far adhesive bonding has primarily been used to assemble and adjust hybrid micro optical systems. However, the properties of the organic polymers used for the adhesives limit the application of these systems. In fields of telecommunication and lithography, an enhancement of existing joining techniques is necessary to improve properties like humidity resistance, laserstability, UV-stability, thermal cycle reliability and life time reliability. Against this background laser beam soldering of optical components is a reasonable joining technology alternative. Properties like: - time and area restricted energy input - energy input can be controlled by the process temperature - direct and indirect heating of the components is possible - no mechanical contact between joining tool and components give good conditions to meet the requirements on a joining technology for sensitive optical components. Additionally to the laser soldering head, for the assembly of optical components it is necessary to include positioning units to adjust the position of the components with high accuracy before joining. Furthermore, suitable measurement methods to characterize the soldered assemblies (for instance in terms of position tolerances) need to be developed.

Since mechanical accuracy is of major importance in the field of optics, piece production is still prevailing and implementations of techniques of mass production are a challenge. Using injection molding of plastic elements onto sheet metals (e.g. so-called OUTSERT-technology) provides a new approach to resolve this issue. Clearly, such a technique could save spacers and retainer rings as well as process time in assembly and allow an economical production of optics mounts at high production rates, if the required mechanical accuracy can be met. For a mobile projection application, the lens barrel of a fix-focus projection lens has been realized in this technology. The design is based on a segmented lens cage with fixed and loose plastic bearings parts for each optical element. Important for accurate lens alignment is a 3-fold symmetry of the cage. Due to the symmetrical layout, reproducibility of the injection molding process is of greater importance than absolute mechanical accuracy. A careful characterization of the constituent parts has been performed, using non-contacting 3d-shape measurements. The data obtained so far reveal satisfying results with respect to reproducibility and selected dimensions of the lens seats. Also, tilt deviations of the lens surfaces in the assembled mount were determined. Further, a preliminary measurement of the Modulation Transfer Function (MTF), to check the optical performance, has been obtained and shows encouraging results.

Through advanced research activities on ultra/nanoprecision and high-quality surface machining processes, required for the fabrication of advanced functional devices, we launched the research and development of a new field of nanoprecision mechanical fabrication technologies for optical elements together with on-machine measurement and evaluation techniques, aiming at a wide variety of materials, and precision and scale ranging from micrometer to nanometer level, to meet scientific, practical and applied industrial needs. This paper introduces their activities for optical elements.

Finishing with grinding wheel is analyzed in viewpoint of grain size and wheel wear modes -self-loosening, self-sharpening and ductile wear modes. A newly introduced parameter -a ratio of surface finish in Ra to grain size- is applied to various kinds of grinding processes. According to the analysis, a new design concept of load specified NC grinding process for realizing specified wheel wear mode, in particular, ductile wear mode is proposed for achieving nano-surface finish.

The progress of modern interference layer design methods and coating technologies is demonstrated by the manufacturing of uncemented, wide-angle thin film polarizers. The requirements are to produce uncemented polarizers for 655nm and an angle of incidence of i=45° +/-6°. The dimensions are 9,5 x 8 [mm] and the surface flatness should be less than 2J15. The items should be manufactured in huge numbers to reasonable costs. The multilayer system was developed by modem design methods. The realisation of such complex design needs very stable properties of the coatings and a sophisticated monitoring system. For this purpose an ion-assisted coating technology was applied. The resulting coatings are shiftfree and mechanically resistant, which is important for the following cutting process. The cutting of large substrates into the required dimension allows the manufacturing of demanding elements to comparatively low costs. Special methods for mechanical stress compensation of the coating system were used to fulfil the demands on the surface flatness.

This note summaries some fundamental aspects on single-point diamond turning technology of brittle crystalline materials for infrared optical applications. The ultra-precision machining mechanism is discussed concerning material property, tool geometry and machining parameters. Some latest results on the fabrication of aspherical optics on brittle materials are also presented.