Ideal for automation, a new kind of UV spot/wand curing system that lowers per unit bonding costs is based on a very short arc, high-pressure mercury lamp. (Note: Lamp are sometimes incorrectly referred to as light bulbs. A spot/wand curing system includes the lamp, a power supply, reflectors, lightguides and shielding.) Called the BlueWave™, this curing system provides as much as 45 W/cm² of actual curing power through a long lived, filtered lightguide. New design options have resulted from this new level of intensity, unique wavelength distribution and long operating life. In addition to at least 2,000 hours of operating life, effective costs are lowered even more by replacing 2, 3 or 4 100 Watt spot cure systems with a single 200 Watt Enhanced Short Arch Mercury Lamp (ESAM) in a 4-pole multiple lightguide system. Additionally, the very high intensity allows the use of rod lens assemblies that provide uniform curing intensity in areas up to five inches square.

The promise of photonics is to provide the next affordable leap in communications and information technology. Low yields and high unit costs are a barrier to mass production. Assembling photonic components economically represents one of the most demanding manufacturing processes in industry today due to the challenges in yield, cycle time and material costs. Manually assembling photonic components will not support the industry's growth rate. Achieving the promise of long term success demands successful automation strategy. Understanding cycle time and throughput and focusing on yield will allow the development of the lowest cost, most successful assembly of photonic, as well as electronic, components.

Practical scientific methods have been devised to measure cure-shrinkage phenomena for a small-volume disk geometry of adhesive agents, in liquid or paste form. These can be conducted simply, reproducibly and quickly, typically 5-120 min, once the apparati are set up. Originally utilised to measure shrinkage behavior in photocuring dental adhesives and biomaterials, the measurements may be applied as well to adhesives for fiber optic and optical applications. They are especially suitable for UV and visible-light curing adhesives. The 'bonded-disk' method is used for the measurement of shrinkage-strain kinetics and the Bioman method for shrinkage-stress of adhesives.

Recent developments in adhesives have yielded products well suited for optical applications. Ultraviolet light-cured adhesives can be cured in seconds and are an attractive candidate. Selection of the adhesive properties can be made to achieve optimum performance. For improved alignment stability and reduced stress, low shrinkage adhesives have been needed. New UV-cured adhesives are evaluated with shrinkage values of less than 0.2%. In addition to controlled bonding for alignment stability, the effects of post-cure UV laser exposure (266 nm) are evaluated. Adhesives needed for systems employing UV lasers must consider off-axis exposure that can cause photo-reactive degradation. Relatively low power laser exposure is used as a simulated source for off-axis or scattered irradiation. None of these candidate adhesives are intended for in-the-light path use at 266 nm, but rather as structural adhesives. Evaluation of these candidates included a outgassing screening test that may be employed to select materials.

To enable the invention of new optical instruments subjected to a broad range of operating conditions, there is a need to develop improved technology to hold small mirrors and other optical elements with high dimensional stability and low cost. A previous paper described a screening experiment on small face bonded mirrors subjected to an environment of -41 to +70 degree(s)C with the intent of finding factors that influence the bond joint's contribution to angular stability. This paper describes part of the continuing experiment, specifically addressing BK-7 mirrors bonded to Aluminum mounts with a flexible adhesive. The resulting tilt errors in the mirror assemblies were measured, and showed a definite pattern with respect to bond thickness. Flexible bonds between these two CTE mismatched materials did not fail, and exhibited high stability over temperature at 0.002-inch bond thickness.

In the glory days of photonics, with exponentiating demand for photonics devices came exponentiating competition, with new ventures commencing deliveries seemingly weekly. Suddenly the industry was faced with a commodity marketplace well before a commodity cost structure was in place. Economic issues like cost, scalability, yield-call it all "Photonomics" -now drive the industry. Automation and throughput-optimization are obvious answers, but until now, suitable modular tools had not been introduced. Available solutions were barely compatible with typical transverse alignment tolerances and could not automate angular alignments of collimated devices and arrays. And settling physics served as the insoluble bottleneck to throughput and resolution advancement in packaging, characterization and fabrication processes. The industry has addressed these needs in several ways, ranging from special configurations of catalog motion devices to integrated microrobots based on a novel mini-hexapod configuration. This intriguing approach allows tip/tilt alignments to be automated about any point in space, such as a beam waist, a focal point, the cleaved face of a fiber, or the optical axis of a waveguide- ideal for MEMS packaging automation and array alignment. Meanwhile, patented new low-cost settling-enhancement technology has been applied in applications ranging from air-bearing long-travel stages to subnanometer-resolution piezo positioners to advance resolution and process cycle-times in sensitive applications such as optical coupling characterization and fiber Bragg grating generation. Background, examples and metrics are discussed, providing an up-to-date industry overview of available solutions.

Precise adjustment of the optical components may be achieved by stepped transfer of momentum via special stroke actuators (impulse hammers), which act onto a pre-stressed fiber- optical component. The motion of the component is controlled by a computer and a measurement device. The present paper discusses theory and experiment of this adjustment method, in particular motion behavior of pushed components under the influence of applied momentum, pre-stressing and frictional forces. Additionally it describes generically the wide application range of this adjustment method. In particular the article describes an innovative, automatic adjustment machine (robot) for the alignment of a single- mode fiber assembly, which was developed by the German Fraunhofer-Institute for Applied Optics and Precision Engineering (IOF) in collaboration with Agilent Technologies Inc., a global technology leader in communications, electronics and life sciences. The achieved adjustment accuracy for the fiber optical assembly is in a low micron range for the focusing motion and in a sub-micron for entering of the optics.

A method has been developed for testing the stability of micro-optical bonds. A white light interferometer is used to measure the movement of micro-optical components after each of a series of Telcordia tests. The micro-optical components were subjected to accelerated high temperature soak, thermal cycling, thermal shock and 500 G mechanical shock. This method allows us to have a high level of confidence that our optical bonds will be sufficiently stable throughout the service life of our tunable laser product. Using accelerated testing techniques and not performing environmental tests that have been shown to induce minimal or no movement, we have found that 30 days is the time required to adequately evaluate the stability of a micro-optical bond design.

We have designed and tested a novel linear actuator system with 1-angstrom closed-loop control resolution and 50-mm travel range. There are two major ultraprecision motion control techniques that have been applied to this actuator: A novel laser Doppler encoder system with multiple-reflection Optics. A specially designed high-stiffness weak-link mechanism with stacked thin metal sheets having sub-Angstrom driving sensitivity with excellent stability. In this paper, we present the system design and test results of this linear actuator. Applications of this new actuator system are also discussed. -Å

System dynamic performance of actuator/stage groups, such as those found in optical instrument positioning systems and other high-precision applications, is dependent upon both individual component behavior and the system configuration. Experimental modal analysis techniques were implemented to determine the six degree of freedom stiffnesses and damping for individual actuator components. These experimental data were then used in a multibody dynamic computer model to investigate the effect of stage group configuration. Running the computer model through the possible stage configurations and observing the predicted vibratory response determined the optimal stage group configuration. Configuration optimization can be performed for any group of stages, provided there is stiffness and damping data available for the constituent pieces.

High-precision instrumentation, such as that for x-ray diffraction, electron microscopy, scanning probe microscopy, and other optical micropositioning systems, requires the stability that comes from vibration-isolated support structures. Structure-born vibrations impede the acquisition of accurate experimental data through such high-precision instruments. At the Advanced Photon Source, a multiaxis goniometer is installed in the 2-ID-D station for synchrotron microdiffraction investigations. However, ground vibration can excite the kinematic movements of the goniometer linkages, resulting in critically contaminated experimental data. In this paper, the vibration behavior of the goniometer has been considered. Experimental vibration measurements were conducted to define the present vibration levels and determine the threshold sensitivity of the equipment. In addition, experimental modal tests were conducted and used to guide an analytical finite element analysis. Both results were used for finding the best way to reduce the vibration levels and to develop a vibration damping / isolation structure for the 2-ID-D goniometer. The device that was designed and tested could be used to reduce local vibration levels for the vibration isolation of similar high-precision instruments.

SMAC Corporation manufactures a wide variety of moving coil based electric servo actuators. These actuators were developed with a specific purpose in mind: To produce tools that would make the automation of assembly easier to accomplish, tools that could perform work in much the same manner as fingers but with more precision. The design targets were: A. Variable programmable accurate positioning down to sub-micron level. B. Variable programmable accurately controlled speeds. C. Variable programmable forces from grams to kilograms. D. Multiple axis configurations to increase degrees of freedom hence flexibility. E. The ability to perform work and verify its success at the same time. F. A low cost design that could eventually compete with pneumatic devices. (SMAC is related to two large pneumatic manufacturers: SMC Corp. and Mac Valve, Inc.) It should be noted that in the past a number of designers have developed voice coil based actuators, the Stout design and patent, with its discussion of programmable force was an early inspiration. SMAC's basic electro/mechanical and software design patents number 20.

A new class of actuators has been developed over the last few years. The actuators use an elastic medium, often a structural grade of alloy metal, as the transducer and are therefore known as elastic actuators. They may be driven by a wide variety of devices ranging from manual micrometer heads to current waveform generators. This paper describes a half-dozen actuator designs and compares the properties (precision, stability, strength and power) of the actuators that have recommended them for particular applications.

A prior publication¹ described a mounting technique using springs to preload a penta prism semikinematically against three coplanar flat pads and three locating pins arranged in a triangular pattern on a baseplate. In that design, the geometry of force application in the plane of reflection led to unequal contact stress generation at the locating pins. With preload high enough to withstand shock or vibration, excessive stress can develop at the pin with the greatest preload. In this paper, we describe a simple modification of the mounting design that more nearly equalizes the stresses at all three pins thereby reducing the potential for damage. We then show how this general technique can be applied to achieve the same stress-reducing advantage in mounting several other standard prism types.

Fast, light weight, off-axis, aspheric, reflective optical designs are increasingly being designed and built for space-based remote sensing, fire control systems, aerial reconnaissance, cryovac instrumentation and laser scanning. Diamond point turning (DPT) is the technology of first resort for many of these applications. In many cases the best diamond machining technologies available cannot meet the desired requirements for system wavefront error and scatter. Aluminum, beryllium, AlBeMet and silicon carbide mirrors, layered with thin films of electroless nickel or silicon can be first diamond machined and then post polished to achieve greatly enhanced performance levels for surface scatter, wavefront error (WFE), and alignment registration. By application of post polishing using precise null testing techniques, the objectives of snap-together, or limited compensation alignment of aggressive reflective optical systems can be achieved that are well beyond the performance envelope achievable by diamond machining alone. This paper discusses the tradeoffs among materials and processes selection for post polished reflective systems and illustrates actual applications including telescopes for earth and Mars orbit, and a commercial, high speed, flat field scan engine.

The title for this paper derives from the method selected for upgrading an older telescope which needed to meet current range instrumentation requirements in the infrared portion of the optical spectrum. A major constraint imposed on the project at its outset was the need to keep the older telescope tube, tracking mount and mobile platform at its home base in Florida. In contrast to the traditional way of building telescopes by first designing the optical system and then designing the housing and mount, this upgrade began with fitting a new structure within the confines of the existing housing while increasing the usable aperture from a 29.5 inch diameter Classical Cassegrainian design to a 32 inch aperture system. This new structure evolved from an improved design approach including the use of low thermal coefficient of expansion materials, special baffles and modern alignment techniques. The tube which was to serve as the bottle, was stripped of its optical components while a completely new internal structure was fabricated independently at a facility in California. The redesign and fabrication process began with a search for the original optical design data and a shopping list of parts to be either modified or redesigned to fit the existing light path through a donut ring which incorporates the telescope's trunnion axis, to a second folding mirror thus enabling an infrared camera to be focused along an overhead track parallel to the telescope's optical axis. All of the original optics were reassembled and potted into new mounts. The secondary mirror was placed into a large ball-knuckle assembly which insured rapid and precise alignment. During the process of building the independent structure, an installation kit or erector set was created. This erector set included special tooling for attaching a large headring, all four metering rods, baffles and adapters as well as the primary mirror retaining ring, inside the original tube. All hardware was shipped to the field site in Florida where final assembly took place using only heavy lifting equipment and a minimum of inexpensive alignment devices.

A novel design of a wide-angle monochromatic x-ray beam shutter is discussed. The shutter is designed as a compact unit capable of providing users with the means of shutting off the beam in secondary beamlines that are at an angle to the primary beamline and to each other. The single-unit design used the fact that all the secondary beamlines will be closed at the same time. The main challenge was to fit the shutter in the limited space of the existing Advanced Photon Source IMMW-CAT hutch. Space limitations led to the change in position of the actuator subassembly as compared to the standard shutter design. Although the actuator subassembly is placed underneath the shutter, fail-safe shutting is achieved by placing tungsten blocks above the beam while the shutter is open and using gravity to close the shutter in case of pneumatic failure. Redundancy required by safety concerns was achieved by duplicating the tungsten block/actuator subunits. Tungsten blocks of uneven length were used to counteract the increase in the center-to-center distance among secondary beamlines due to their angular offset. A special support table was designed to facilitate assembly and adjustability of the shutter position in the available space. To provide a radiation-tight hutch, a non-standard guillotine system was designed. In this paper, the design, specifications and optical ray tracing of the shutter assembly are presented.

Optical systems with long production life cycles can encounter cost saving vendor and/or technology changes that may be difficult to incorporate into the system without total system redesign. Many times, these developments could result in significant cost savings of the hardware, but the level of up front investment in system redesign and qualification tends to nullify the hardware production cost advantage. The subject of this paper, is a cost reduction effort to redesign, and replace a high cost metallic primary mirror. The use of less costly materials is the major cost saver, but this can lead to poor athermal system performance without other system changes. The technique used in this application is tuning an optical replication process to athermalize the new mirror into the existing optical train.

This paper presents the lessons learned during the design and development of a high performance cooled CCD camera for military applications utilizing common commercial off the shelf (COTS) parts. Our experience showed that concurrent evaluation and testing of high risk COTS must be performed to assess their performance over the required temperature range and other special product requirements such as fuel vapor compatibility, EMI and shock susceptibility, etc. Technical, cost and schedule risks for COTS parts must also be carefully evaluated. The customer must be involved in the selection and evaluation of such parts so that the performance limitations of the selected parts are clearly understood. It is equally important to check with vendors on the availability and obsolescence of the COTS parts being considered since the electronic components are often replaced by newer, better and cheaper models in a couple of years. In summary, this paper addresses the major benefits and risks associated with using commercial and industrial parts in military products, and suggests a risk mitigation approach to ensure a smooth development phase, and predictable performance from the end product.

A new concept of electromechanical shutter has been designed and qualified for the OSIRIS imaging system to fly onboard the Rosetta Mission, whose main scientific goal are the randez-vous and the study of the Comet Wirtanen. The shutter, is composed by two blades, driven by dedicated four-bar linkages, that are moved independently by two torque motors each mounted on the same shaft of an high resolution optical encoder. A dedicate fail safe mechanism is also integrated in order to make the shutter single point failure proof. The mechanism has been designed in order to fulfil high reliability with high performance. Reliability has been verified by life testing over 100000 cycles (factor 2 on expected operative cycles). Performance verified by calibration show that the minimum exposure time with a uniformity of 1/500 is 10 ms over a large sensitive area (about 30x30 mm). The exposure time can vary from 10ms to 5s. Scope of this paper is to present the mechanism and to demonstrate that it accomplishes the sciences and interfaces requirements.

The scope of the present document is to describe the Front Door Mechanism of Wide Angle Camera and Narrow Angle Camera of the OSIRS payload and to demonstrate the safety of the mechanism itself. To match the scientific goals it has to prevent the contamination of the telescopes during ground and in -flight operations. Moreover for the in-flight calibration the door itself will be used for the flat field of the cameras. The original design has been carried out according to optimisation techniques and successfully tested during the qualification and acceptance campaign. The results obtained demonstrated that the mechanism is fully compliant to the interface specifications and its performances are not affected by the environmental stresses and by the overall life cycling.

The 2003 mission to Mars includes two Rovers, which will land on the Martian surface. Each Rover carries 9 cameras of 4 different designs. In addition, one similar camera is mounted to each lander assembly to monitor the descent and provide information for firing the control jets during landing. This paper will discuss the mechanical systems design of the cameras, including fabrication tolerances of the lenses, thermal issues, radiation shielding, planetary protection, detector mounting, electronics, the modularity achieved, and how the 10 different locations were accommodated on the very tight real estate of the Rovers and Landers.

The paper will focus on three main areas; thermal and physical characterization of the new O-30 optical grade of beryllium at cryogenic temperatures; the development of a leachable mandrel technology for near net shaped (NNS) parts in beryllium and AlBeMet®; finally the paper will report on the optical characterization of AlbeMet® as an optical substrate material.

Ceramic mirrors and complex structures are becoming more important for high precision lightweighted optomechanical applications. Carbon-fiber reinforced silicon carbon (C/SiC) is a composite ceramic material consisting of SiC as its major constituent. Developments over the past 10 years by IABG, ECM, and Astrium GmbH have demonstrated the feasibility and versatility of this ceramic material for different applications. The most favourable characteristics of the material are high stiffness, high thermal conductivity and low thermal expansion (CTE). Furthermore, Cesic -- a trademark of ECM for C/SiC -- allows relatively quick and cheap manufacturing of components because the components can be shaped with conventional tools in a milling and/or drilling process of the greenbody material. Through a joining process and our new development of optical surfaces based on a slurry cladding technology, CesicR allows for a direct up-scaling of structures and optical surfaces to large size applications and systems. The size of the structures and mirrors that can be manufactured is limited only by the scale of the available production facilities, the largest of which currently is 2.4 m in diameter.

Silicon carbide (SiC) has long been recognized as an attractive mirror material due to its superior mechanical and thermal properties when compared to conventional optical materials. However, the material properties of SiC which make the material attractive from a design standpoint have often precluded its use when low cost and rapid delivery of an optical mirror were required. This paper describes an approach that was developed by Zygo Corporation, working in conjunction with POCO Graphite Inc. for the rapid fabrication of lightweight silicon carbide optics. This approach utilizes a SiC substrate produced by POCO Graphite Inc. using a non-traditional process coupled with deterministic finishing techniques developed by Zygo. Using this approach, we are now capable of producing high quality prototype components (λ/10 PV figure, 10 Å rms. micro roughness) of SiC within a few weeks, rather than the traditional period of months. Applications include lightweight scan mirrors, stage mirrors for lithography positioning tools, as well as similar applications where high stiffness and low weight are significant performance parameters. MRF polishing results comparing SiC to conventional optical materials are also presented.

Electroless nickel is often plated on the surface of aluminum mirrors to improve the ability to polish the mirror surface. Electroless nickel plating can cause a bimetallic effect, creating distortion of a mirror surface if it is heated or cooled. Published data listing the thermal coefficient of expansion and Young's modulus as a function of temperature for electroless nickel is not readily available. This study examined using bimetallic bars to measure the Young's modulus and thermal coefficient of expansion of electroless nickel as it is cooled from room temperature to 100 K. A test chamber was developed which can accurately measure the rotations of a bimetallic bar as it is cooled. Elementary beam theory equations for a bimetallic beam were developed. These equations indicate that by testing beams with a variety of beam thicknesses, one should be able to determine modulus and thermal coefficient of expansion data for electroless nickel. The results show that the method fails to find accurate values. Very small measurement errors cause large changes in the modulus values. By using typical values for Young's modulus and the measured beam rotations, values for thermal coefficient of expansion for electroless nickel were obtained.

Silicon carbide may well be the best known material for the manufacture of high performance optical components. A combination of extremely high specific stiffness (r/E), high thermal conductivity and outstanding dimensional stability make silicon carbide superior overall to beryllium and low-expansion glass ceramics. A major impediment to wide use of a ceramic material such as silicon carbide is the ability to create a design that fully utilizes these properties while addressing limitations such as brittleness. This paper discusses an approach for design that will optimize the use of properties while considering the manufacturability of the component. POCO has developed a manufacturing process that lends itself to efficient design of complex optical components. The manufacturing process described here-in begins by machining the component from a special type of graphite. This graphite is easily machined with multi-axis CNC machine tools to any level of complexity and lightweighting required. The graphite is then converted completely to silicon carbide with very small and very predictable dimensional change. After conversion to silicon carbide the optical surface is coated with very fine grain silicon carbide which is easily polished to extreme smoothness using conventional optical polishing techniques. The design approach presented requires an iterative process between the 'system' designer and the materials and component designer. Both he fabrication process and the design approach are described in this paper.

Zernike polynomials are an orthogonal set over a unit circle and are often used to represent surface distortions from FEA analyses. There are several reasons why these coefficients may lose their orthogonality in an FEA analysis. The effects, their importance, and techniques for identifying and improving orthogonality are discussed. Alternative representations are presented.

Proper finite element modeling of nearly incompressible bonds which are commonly used to mount optics requires special considerations. Modeling difficulties arise due to the geometries of the mounting designs and the incompressible nature of the bonding materials involved in many applications. Therefore, specific methods of modeling must be employed. Such methods of modeling two common bond designs are outlined. Treatment of these modeling methods includes why they are needed, how they are performed, and what their limitations are.

Selecting the proper thickness of high shape factor bonds using near incompressible adhesives is critical to minimize the elastic response of the bonded optical element. For incompressible adhesives with low shape factor, variations in the bond thickness are shown not to be as critical. This is illustrated in the evaluation and redesign of an RTV bond for a primary mirror of a Cassegrain telescope. The initial bond was oversized and highly constrained resulting in focus errors in the telescope during optical testing. Subsequent redesign of the bond thickness to athermalize the design compared various closed-form solutions and finite element parametric studies.

Over the past several years we have designed and fabricated several variations of a three mirror anistigmat Telescope for a Risk Reduction effort. In order to achieve passive athermalization, use of the same materials for both mirrors and structures is desirable. We fabricated 2 telescopes using investment cast aluminum alloy A356 in the first and investment cast Aluminum/Beryllium alloy 191 in the second, for all components. All optical surfaces and corresponding mounting surfaces are nickel plated and single point diamond tuned. The telescopes were assembled to meet the optical prescription tolerances with no alignment required other than focus. Components and performance levels are totally interchangeable between the telescopes, except for athermalization issues.