Previously published analytical techniques are extended for analyzing axial stress developed within a lens or similar rotationally symmetric element clamped into a mount by a retainer to include toroidal optomechanical interfaces.

Optical designs often consist of lenses which are mounted in a common lens barrel. One method for mounting these lenses is to mount each individual lens in its own subcell using an adhesive and then use an interference or press fit to mount these subcells in the lens barrel. When mounting lenses in this manner, it is necessary to evaluate the stress induced in the glass and the residual difference in the optical path. A closed form analytical derivation was made for a simple lens mount that relates the allowable magnitude of the interference fit to the stress in the glass. This theoretical expression was modified using finite element models in order that it may be used for complex lens designs. Proper modeling such as element material properties are addressed, as well as applications for various mounting conditions.

The equation for determining the decentering of lenses mounted in a circumferential flexible elastomer is derived. A closed form analytical solution was derived for a circular lens mounted in an elastomer to describe this deflection. The theoretical expression was used to verify finite element models which then may be used for more complex mounts. Proper modeling such as element type and aspect ratios are addressed as well as applications of the method for various mounting applications.

We were tasked recently with the design and production of an ultra-precision projection lens. The lens performance was extremely demanding, calling for a near diffraction limited MTF and a distortion requirement of less than or equal to 20%. In addition to the extremely demanding optical performance requirements, the system had to withstand a storage temperature range from -55°C to +95°C, and the lens had to perform over a somewhat smaller range. In the following paper we will describe some of the optical challenges of the design, followed by a detailed explanation of the opto-mechanical design and the elastomeric mounting schemes developed herein.

This paper describes the optomechanical design, thermal analysis, fabrication, and test evaluation processes followed in developing a rapid cooled, infrared lens cell. Thermal analysis was the key engineering discipline exercised in the design phase. The effect of thermal stress on the lens, induced by rapid cooling of the lens cell, was investigated. Features of this lens cell that minimized the thermal stress will be discussed in a dedicated section. The results of thermal analysis on the selected lens cell design and the selection of the flow channel design in the heat exchanger will be discussed. Throughout the paper engineering drawings, illustrations, analytical results, and photographs of actual hardware are presented.

In this paper, a review is given about recent problems in binocular design. In particular, the influence of the prism system is discussed and different mounting techniques of prism systems are presented. The effect of antireflection coating of prisms is described. As known since the early 1940s, the rotation of the plane of vibration by total internal reflection at the two roof surfaces causes a loss in resolution and contrast. By a special coating of the roof-edge surfaces this effect can be compensated. MTF-measurements give a quantitative analysis of the effect.

A high quality Multiple Diode Laser (MDL) has been built that combines 16 Spectra Diode Lab's laser diodes into a single beam using both wavelength and polarization combining. The MDL was designed and built to space flight requirements. Critical submicrometer tolerances to achieve wavelength stability, beam collimation, and beam coalignment and stability were met using developed repeatable processes. The most stressing optomechanical requirement was the placement and cementing of an external etalon very accurately positioned 36.3 +/- 0.05 micron from the diode to control the wavelength of the diode output. The second most stressing optomechanical requirement was maintaining the source decenter from the optical axis of the collimating lens to +/- 0.09 micron to insure coalignment of the 16 diode beams. The design and process techniques used to achieve these most critical optomechauical tolerances will be described as well as MDL performance achieved through environmental testing.

We will discuss the optomechanical design of components used for free space optical switch prototypes built to develop potential solutions for the high-speed digital switching problems of bandwidth, interconnection, and density. In our free space optical switching fabrics, arrays of light beams propagate between array of optical transceiver devices called Symmetric Self Electro-Optic Effect Device (S-SEED). These arrays have been operated with more than a thousand beams incident on device windows typically 5 microns in diameter. To image the arrays required high resolution optics, tight component tolerances, and stable mounting techniques. This paper explains the optomechanical design and construction of the components of the free space optical switching fabric, designed under requirements of small size, high resolution of movement, mechanical stability, and minimal cost. Comparisons are made between two versions of experimental components, including S-SEED mounts and mounting plates.

Parts of a multistage switching network were implemented by optically interconnecting arrays of symmetric self electro-optic effect devices. In an experiment completed last Spring, three 16 X 8 arrays of S-SEEDs, all operating as logic gates, were optically connected. A fully-interconnected switching fabric using six 32 X 32 S-SEED arrays is currently being tested. These are the latest in a series of experiments to investigate and develop this technology, and they substantially involve optomechanics. The practical realization of this technology represents a challenge to modern optomechanics due to the required precision, stability, and number of components involved. An overview of free-space photonic switching and the required experimental hardware subsystems is presented, followed by details of the optical systems to interconnect the switching device arrays and the mechanical systems which locate and position the optics and devices. The tolerancing analysis used in these systems is reviewed and comparisons between the two systems are made.

The continuous progress in material and component technology has generated new laser-based applications that require special packaging techniques. Hybrid integration offers a flexible method to accomplish custom design needs. This paper discusses several aspects in fiber optic packaging including optical, thermal, and mechanical issues. Special emphasis is on optical coupling between a laser diode and a single-mode fiber.

A compact and versatile 32-wavelength spectrometer module has been developed based on a linear LED array and a fixed grating monochromator. The design includes all the optical, mechanical, and optoelectronic parts in a size of approximately 4 x 4 x 7 cu cm. The wavelength bands are scanned electronically without any moving parts. All the optical parts have been assembled to form a cemented solid glass construction, which is mechanically and thermally stable and well protected against water condensation or dust. The developed source module can be easily modified and has obvious advantages for spectroscopic analyzers, especially in process and portable applications.

The feasibility of a passive bidirectional fiber optic bus and the packaging considerations of a bus access module have been studied. The bus uses 110/125 micrometers HCS fiber and passive integrated optic couplers for bus access. The access couplers are asymmetric and were fabricated using a Ag-Na ion exchange process. The asymmetry of the coupler was 5 dB, the launch loss to the bus was 6 dB and the tap-off loss to the node was 11 dB. With the integrated optics coupler it is possible to connect 6 nodes to the bidirectional bus. It is also possible to realize a simple, easy-to-use, and reliable bus access module for intramachine communication. The integrated optics coupler, a LED chip, and a PIN-diode chip and transceiver electronics are packaged in an electrical connector with a two-fiber optical cable pigtail. Active and passive components are butt coupled to the coupler. The 0.5 dB alignment tolerances for the fiber pigtails, the LED, and the PIN-diode chips are +/- 5 micrometers .

Unless corrected, non-planarity and rate non-uniformity occur in the scanned BIRS beam as a result of scan mirror geometry and magnification variation with field angle. These scan distortions will be discussed together with a method for determination of scan mirror control algorithms for their correction.

In order to improve the accuracy of simulation for 3 axes servo revolution pedestal system (TARPS), stability analysis of the system is carried out. In view of integration of the mechanical structure and servo control subsystem, this paper describes the foundation and assembly of modal equations for dynamical substructures, connectors, and servo controller of TARPS. This study evaluates the influence function from the mechanical aspect and servo control aspect, and points out ways of improving dynamical stability of TARPS. This paper details mechanical structural finite element models, servo control mathematical models, and coupling between the mechanical structure and servo controller, the overall design develops through an iterative process based on trade-off between the mechanical subsystem and the servo controller.

An optical synthetic telescope is being planned for production by Nanjing Astronomical Instrument Factory. This telescope is to be set up for use at Xinglong station of Beijing Astronomical Observatory.The 4.3 meter optical infrared new technology telescope is an altazimuth-mounting telescope. Through the fiber combination of 4.3 meter telescope and some currently used optical telescopes. Xinglong station will enhance its concentrating light power up to that of a 5.1 meter telescope. Through the vacuum pipe combination of the 4.3 meter telescope and the 2.16 meter telescope and by using CCD photography and optical interfering measurement, it will enhance its resolution to that of a more than a 10 meter telescope.

The positioning accuracy, photographical frame frequency, and resolution of intermittent high- speed cameras are strongly affected by the dynamical behavior of the embodied high-speed gear mechanism, especially under high-speed conditions. In order to make the camera work in a steady state, it is necessary to predict the influence function of transmission of the gear mechanism before making a prototype. In this paper, the dynamical performance for transmissive mechanism and its effect on optics system are discussed. The model construction of high-speed gear mechanism is given in detail. Sensitive factors and the dynamical balance for the mechanism have been analyzed as well.

This paper presents a new high-accuracy micro-displacement positioning system controlled by a diffraction grating interferometer. The principle and technique are given, based on which micro-displacements are measured by an interfering system consisting of a spectral grating. In order that the interferometer is stable and reliable for several days and nights, the interfering signals are program-controlled. The movement of the diamond is even and smooth due to locked phase of the bridge generator with frequency division of crystal oscillation. The locked phase of the interfering signals with the bridge is controlled by Bang-Bang and PID modes. The movement accuracy of the engine is measured and analyzed by interpolation. The division error: (sigma) <3.1 nm. The grating quality can be determined from the spectral contour obtained by Fourier transform. As a result, it is corresponding with that obtained by spectral means.

This paper describes a method to analyze overall accuracy of an aerostatic slideway made from granite. Working equations of the aerostatic slideway and precision theory of fine mechanics are used to derive a series of aerostatic slideway calculating equations. It presents the view of multiple. The final measuring results are given by Laser Transduser System 5501A. The horizontal error σ_x = +/- 0.06"(m.s.e.). The vertical error σ_x = +/- 0.09"(m.s.e.). This kind of aerostatic slideway made from granite has been used in photoetching machines.

Early on in the development of glass Code 7971 ULE^TM, Corning recognized that applications demanded thermal expansion measurements with higher precision and accuracy than that available. Hence a program was launched starting with 10cm path laser Fizeau interferometry to establish an absolute base. Differential methods followed with large sandwich seals and a high precision vitreous silica superdilatometer. Destructive in nature, these tests led to a nondestructive ultrasonic procedure that permits absolute and differential measurements with an uncertainty of +/- 2 ppb/ degree(s)C and reliably performed at the manufacturing plant. Details of these measurement systems are described along with optional experimental variations. A principle, established with seal testing, is reviewed showing that expansion differentials in ULE^TM are independent of temperature. Finally, recent plant measurements of both axial and radial thermal expansion variations in ULE^TM boules are presented.

Much has been written about structural relaxation, viscous flow, delayed elasticity, hysteresis, and other dimensional stability phenomena of glass and ceramics at elevated temperatures. Less has been documented about similar effects at room temperature. The time dependent phenomenon of delayed elasticity exhibited by Zerodur has been studied at room temperature and is presented here. Using a high-performance mechanical profilometer, a delayed strain on the order of 1 percent is realized over a period of a few weeks, under low stress levels. An independent test using optical interferometry validates the results. A comparison of Corning ULE silica glass is also made. The effect is believed to be related to the alkali oxide content of the glass ceramic and rearrangement of the ion groups within the structure during stress. The effect, apparent under externally applied load, is elastic and repeatable, that is, no hysteresis of permanent set, as measured at elevated temperature, is evidenced within measurement capabilities. Nonetheless, it must be accounted for in determining the magnitude of distortion under load (delayed elastic creep) and upon load removal (delayed elastic recovery). This is particularly important for large lightweight optics which might undergo large strain during fabrication and environmental loading, such as experienced in gravity release or in dynamic control of active optics.

Dose gradients in large mirror substrates due to unequal exposure to the natural space radiation environment have been calculated for two circular orbits: 1200 km altitude/98 deg inclination and 3700 km/30 deg. Dose gradients were translated to density-change profiles based on experimentally determined density changes as a function of dose for fused silica and the low-CTE glass ceramic, Zerodur-M. Finite element analysis of deformation due to the radiation-induced density gradient was performed for a 4 meter by 0.5 cm disk representing a mirror faceplate. Displacements of nearly 2500 micrometers at the outer edge were calculated for a Zerodur faceplate after 10 yr at 3700 km/30 deg. Silica, which is much less sensitive, deformed by only a few angstroms. Reinforcement with a backing having the equivalent stiffness of 5 cm of SiC resulted in a 10-fold decrease in the calculated deformation.

Future NASA missions such as the Great Observatories of the 21st Century require structures which can be maintained with micron to nanometer accuracy. This dimensional stability (OS) must be maintained over the 5 to 10 years of mission lifetime. A high DS, which in this case means the system's ability to retain geometrical properties related to the system's performance, will most likely be achieved by a combination of dimensionally stable materials and active controls. Actively controlled structures can achieve a very high degree of DS. However, the inherent instability of the building blocks limits the ultimate DS which can be realized. This article discusses basic limitations on the DS which can be achieved by an actively controlled system which uses passive materials with limited stability. Thermodynamics limits the ultimately attainable DS. For example, the amplitude of the longitudinal vibration in a space truss structure is related to the temperature of the structure. The amplitude of this axial vibration grows with increasing temperature. Another instability mechanism is the temperature gradients through so called "zero coefficient of thermal expansion (CTE)" materials. "Zero CTE" materials will, under some conditions, show no change in at least one dimension when the material is heated. We will show, that in non-equilibrium conditions "zero CTE" materials can behave as if they had a CTE nearly equal to double the CTE of their stiffest phase. These and other mechanisms influence the space system's performance below 0.1 part per million dimensional stability.

The performance requirements for long life, high-resolution ultraviolet and visible wavelength remote-sensing spacecraft instruments are very stringent with respect to dimensional stability. For example, full focus budges for instruments such as the Jet Propulsion Laboratory (JPL) CRAF/Cassini spacecraft imaging science subsystem and the California Institute of Technology/JPL Mars Observer Camera are in the range of 0.1 micrometers per centimeter of focal length. Advanced materials having low density, high specific strength and stiffness, and good dimensional stability offer design flexibility and new opportunities to develop more sophisticated remote sensing instruments. This paper reports a study to evaluate the dimensional stability of two classes of low-density, high specific strength metal matrix composites and an aluminum-lithium-magnesium metal alloy.

The sources of dimensional instability in graphite/epoxy structures are numerous and can be both micro or macro in nature. They can be related to environmental changes, part geometry, laminate orientation, microcracking, and other factors. Past and current experiences in working with graphite/epoxy to fabricate dimensionally stable instrument structures at Composite Optics, Incorporated, has given rise to new understanding and techniques for achieving higher degrees of dimensional stability. This paper describes these sources of dimensional instability, provides alternatives for minimizing or eliminating them, and presents test data illustrating the effectiveness of these techniques used to dimensionally stabilize a graphite/epoxy structure.

A matrix of experiments was used to diagnose the presence and effect of surface stress in single crystal silicon as a result of various optical fabrication processes. These experiments employed a series of prepolished silicon samples, 4.5 inches in diameter, one surface of which was then subjected to fabrication procedure(s) typical to the refinement of a silicon optical component. The unaltered face was preserved in its originally-polished condition and interferometrically measured to detect changes of contour resulting from changes in stress characteristics imposed on the opposite, altered face. Samples representing specific process histories were periodically removed from the matrix and retained for long-term observation and assessment of any transient behavior. For comparison, a series of unaltered samples were retained for observation in the originally-polished condition, and a series of disks were also processed through the matrix from a rough blank state. the data collected during this effort are presented and discussed.

The LEO-Terminal of the ESA project SILEX (Semiconductor Intersateffite Link EXperiment) must provide a high pointing accuracy to be able to establish an optical inter orbit communication link. An alignment accuracy of 0.01° is required at the interface to the host satellite including the interface structure of the terminal to provide the necessary open loop pointing accuracy for acquisition of the counter terminal. Perturbations during launch, thermoelastic deformation and long term shrinking of the interface structure material CFRP are the determining sources of misalignment. The critical tilting of the interface structure can be reduced by means of slots for the fixation bolts, allowing translatoric movements at the interface fixation points in proper directions. Perpendicular movements to the selected direction (e.g. thermoelastic deformation and vibration during launch) must be strictly suppressed to avoid tilting in the plane of the attachment points at the interface satellite to terminal. Interface adapters at each connection will be used to overcome the problem of integrating the terminal with the tight toleranced fixation slots on the host satellite. One side of the adapters fixed to the terminal interface structure will provide the tight toleranced slots. The other side of the adapter will provide holes with sufficient large tolerances for the bolts used for the fixing of the terminal to the host satellite. These bolts are designed to fix the terminal rigidly under all environmental conditions by friction.

From a viewpoint of the up-to-date requirements, fundamental scientific and technological problems arising in design and manufacture of the optical reflecting telescopes are formulated as compared to those of the retracting systems. Nontraditional materials, such as beryllium, silicon, silicon carbide, etc., are shown to be capable of successful competition with the traditional optical materials used for the telescope mirror. Certain technological features and results obtained at GOI Metal Optics Division are briefly overviewed concerning the beryllium-based mirrors development.

A new method of numerical calculation of MTF is presented here for image motion in one- dimension. The method is applicable in principle to any type of motion and can be expanded to two-dimensional motion. It is applied here to uniform velocity motion and to sinusoidal vibrations. Comparison to known analytical methods is made where possible, and agreement is excellent. This supports its implementation to any kind of random motion, particularly where no unique analytical MTF is possible.

This paper presents an electro-optical device to characterize misalignments of solenoid magnets. Optimal transport of the Linear Induction Accelerator's electron beam of CESTA (France) is attached to the quality of this alignment.