The modulation transfer function of bar code scanning is a useful tool for evaluating the performance of the scanning laser beam. Understanding the behavior of the scanning laser system near the end of its depth of focus is of particular interest because it may lead to the development of techniques that could effective extend the depth of focus. In the article the MTF at focus and the two extremes of the depth of focus are presented. The presence of spherical aberration in the scanning laser beam generally reduces the depth of focus. The effects of the spherical aberration to the MTF is presented and discussed.

Over the past twenty years numerous papers and patents have reported on the design of infrared zoom lenses for a variety of civilian and military applications. The vast majority of these lenses have been afocal 8 - 12 micrometer zoom lenses with magnification ratios of five to twenty. With the advancement of 3 - 5 micrometer staring focal plane array technology a growing demand has emerged for a compact imaging 3 - 5 micrometer zoom lens. To meet this demand a variety of such zoom lenses have been designed which support image formats of over 10 mm diagonal. In this paper the preliminary design of a high magnification 3 - 5 micrometer zoom lens is described. Infrared system modeling, detailed lens performance and manufacturing issues are reviewed.

Detector developments raise the possibility of achieving high resolution images, employing linear arrays of over 3000 pixels, in any of the atmospheric windows extending from the visual to the far infra-red. Simultaneous capture with fusion of the VNIR, MWIR & LWIR images requires a reflective optical system. Reasons are given for the choice of a 4 mirror anastigmatic telescope for the basic imaging system which is combined with another 4 mirror afocal telescope to cover a 60 degree field in wide angle mode. To permit ground based trials, a mirror scanner covers a 40 degree field in either mode. Choice of a telescope with projected entrance pupil was essential for a compact system. Focus and mode changes are all made by the movement of flat mirrors. A particular arrangement of these folds contributes towards a rational structure with the mirror groups mounted on optical axes perpendicular to a common base. The methods used to ensure dimensional stability including the design and mounting of the beamsplitters are described.

In an effort to improve the performances of streak cameras, experimental and theoretical studies were conducted, aimed at measuring the noise in a camera. This would be achieved through the evaluation of the camera's noise factor and by additionally pointing out the possible sources of noise. It was shown for our camera, a TSN 506 Thomson camera, that the noise factor is due partly to signal loss (factor 1,8) and partly to noise addition (factor 2,6). Moreover, noise was shown to be additive and Poissonian, mostly due to shot noise and photoelectric conversions.

The present paper relates to an optical module of a compact hybrid video color mixer for large-area laser projection display. The compact optical arrangement gives a very small- sized and high-performance video image color mixing apparatus which uses a hybrid R/G/B color separator, modulate the light beam using a 3-channels acousto-optic modulator according to the video image signal and combines the modulated R/G/B beams to one beam using a hybrid R/G/B color combiner. A high performance video image projection apparatus can be realized using a light source, a hybrid video color mixer and a X-Y scanner set. The present hybrid video color mixer is suitable for a future domestic laser TV application.

A critical component in the 2-micrometer coherent spaced-based lidar system (SPARCLE) is the compact, off-axis, 25-cm aperture telescope. The stressing optical performance demanded from this telescope coupled with the difficulty associated with aligning such a fast, off-axis system; has created the need for a multiple-axis alignment stage for the secondary mirror. Precision micrometer kinematic mounts were used in the laboratory to demonstrate the ability to successfully align the telescope. For the flight configuration, a more robust and considerably smaller stage (both in size and weight) had to be designed in order to fit within the space shuttle packaging constraints. The new stage operates with multiple degrees of freedom of motion to achieve micrometer precision alignment and then uses a mechanical multiple point support to lock-in the alignment and provide stability. The optomechanical design of the flight stage is described.

The development of soft x-ray optics demands an extremely smooth aspherical mirrors with a geometrical accuracy in the sub nanometer range. So far several fabrication methods that utilize high precision machining operations, ion beam milling and plasma assisted chemical etching have been under study with each method having its own advantages and disadvantages. This study introduces a new fabrication method that makes use of an oil pressure to elastically deflect a finished spherical surface. The validity of the proposed method is assessed an the effective parameters are defined.

The image quality, performance and long-term stability of an optical system depends on a number of factors including the optomechanical design, and fabrication and thermal stabilization methods used for making the optical components and support structures. The distortion of optics due to mounting and the differential thermal expansion as a result of temperature changes is by far the biggest sources of image degradation. In all-reflective and catadioptric systems consisting of spherical and aspherical mirrors, very small stress induced at the mounting interface can adversely degrade the surface figure of a mirror, thereby causing significant image distortion and a severe drop in the system MTF. This paper presents a number of design techniques for mirror mount, which have been successfully used to greatly reduce or isolate the mounting stresses and, thereby, resulting in a minimal degradation of mirror surface figure. Some of these methods include using flexures, dowel pins, precision machining of the interfaces, and providing cut-outs to isolate the stresses from clamping screws used for securing the mirrors to support structures. Various mounting design options are presented especially for diamond-machined metal mirrors.

Previously published theory providing means for estimating contact stresses in lenses due to axial mounting constraints is extended to allow similar calculations for mechanically- clamped prisms. The results can be compared to 'rule-of-thumb' survival or operational tolerances on compression contact stress for the applicable optical material to determine if a given mounting design appears adequate or if more precise methods, such as finite element analysis and statistically- derived tolerances, should be applied. Examples are given to illustrate typical applications of this new theory.

In deterministic microgrinding of glass optics with metal bond diamond ring tools, optical surfaces exhibit residual cutting tool marks that can significantly affect the efficiency of the finish polishing process. The tool marks for spherical surface generation appear as curves that follow contact lines between the tool and workpiece from the center to the edge of the workpiece. The tool marks are circumferentially periodic and the number is typically equal to the k-ratio, i.e. the ratio of grinding tool speed to workpiece speed. This paper describes the effect of the k-ratio, the tool cutting face width, and their interaction on tool mark generation. We introduce a new parameter equal to the ratio of tool cutting face width to the k-ratio spacing. Experimental results indicate that this ratio is the critical factor for tool mark generation. For ratios greater than a critical value, the amplitude of tool marks will be reduced to a level not detectable by interferometry. The influences of vibration and tool roughness are also discussed. The model presented provides new insight into the generation of tool marks and optimization of deterministic microgrinding processes.

2,3-dimercaptoethylthiopropanethiol (B-thiol), 2,2'- dimercaptoethyl sulfide dimethacrylate (MESDMA), and 2- phenylthioethyl thiomethacrylate (MEPSMA) were prepared, which structures were confirmed by IR and ¹HNMR spectroscopy. A series of homopolymer resin (such as, B-thiol/MDI) and copolymer resin [such as MESDMA/St (25 to approximately 50%), and MESDMA/St/MEPSMA] were further prepared, which optical and mechanical properties were much better than those of the ordinary resins. The studies and development of such optical resins would be expected to meet the need of optical resin markets.

Ultrasmooth optical surfaces are of important application due to low-loss and low-scatter properties. Especially, in soft X- ray region, the surface roughness of substrates of multilayered mirrors is demanded to be below 1 nm rms. Furthermore, the excellent reflectors usually take advantage of the surface roughness less than 0.1 nm rms. Polishing by a tin plate is one of the remarkable methods for fabricating mirror surfaces. We studied the tin polisher for polishing ultrasmooth surfaces. The characteristic of tin as a polisher material is presented. Non-contact, direct-contact and selfweight polishing states are studied. Polishing experiments on many materials are carried out with perfect surface quality. Surface roughness around 0.5 nm rms is obtained on BK7 glass, Zerodur, and sapphire plates. This paper submits a profile of the work on superpolishing with a tin polisher.

A compact and stable 20-beam injector was built for launching laser light into fibers for Fabry Perot velocity measurements of shock-driven surfaces. The fiber injector uses commercial mounts on mini-rails. Dielectric-coated beamsplitters provide accurate amplitude division. Minimal adjustments for stable operation are permitted by the use of a real-time video- viewer. The video system includes a non-linear camera for CW alignment and a linearized camera with a frame grabber for pulsed measurement and analysis. All 20-injection points are displayed on a single monitor. Optical requirements are given for image relay and magnification. Stimulated Brillouin scattering limitations on high-power are quantified.

A comprehensive illuminator has been designed and constructed for complete test or characterization of CCD and CMOS image sensors. By changing the position of a multi-grating turret of a Czerny-Turner type monochromator from a grating to a highly reflective mirror, two modes of operation can be achieved. Monochromatic flux is generated when the turret is set to the normal grating position and broadband light is generated when the turret is set to the mirrored position. The flux is directed through an aperture and collimated to form a uniform, wide-field, monochromatic or broadband source. An in-situ calibrated detector along with two automated filter wheels is used to monitor monochromatic irradiance, illuminance and color temperature. Testing of image sensors for parameters such as well capacity, sensitivity and linearity can be made for broadband illumination whereas spectral responsivity and quantum efficiency measurements of the image sensor can be made over the wavelength range of 380 to 800 nm. An in-situ calibrated detector is used for absolute light calibration in both intensity and correlated color temperature. Two filter wheels and high-speed shutter have been integrated into the light path of the monochromator to enable the automatic control of output light intensity, shape and color. Stages are also provided for slide pattern projection and aperture control. This illuminator is able to output a 2'-diameter beam with less than 5% non-uniformity. The maximum broadband light output is close to 400 lux, and has 90 intensity control steps. The spectral test mode can cover visible wavelength range with resolution up to 0.5 nm. Software has been configured to do automatic mode change and testing. By designing standard image sensor illuminator functionality into a spectroradiometer, we have achieved a compact, multi- functional, automated, low-cost illuminator for image sensor testing and characterization. The option of adding a fiber optic to the system allows easy integration of the illuminator into any laboratory or production equipment such as a prober station or a packaged parts handler.

This paper is directed at the analysis of the basic operating principles, design, operation, and performance of a different type of optical modulator, capable of large phase modulation through the change of the optical index of refraction. This is achieved by modification of waveguide boundary conditions by incorporating quantum wells that can be charged or emptied of electrons at the planar dielectric waveguide boundaries, by application of gate voltages. Such an unconventional way of achieving the desired modifications in the optical refractive index will provide attractive alternative and more versatility than the conventional means of realizing such modifications, such as electro-optical effects (electroabsorption, Franz- Keldysh effect, optical birefringence), carrier induced effects (band filling, band gap renormalization), and free carrier absorption (plasma effect). Furthermore, the technology (e.g. molecular beam epitaxy, metalorganic chemical vapor deposition, ion beam etching, and other micro machining techniques) of fabrication of these new devices is already in place, so the proposed concept can be tested to facilitate further development. Based on these projections, we propose a planar-based dielectric waveguide having confined electrons in quantum wells at the boundaries. Microstructure devices made from semiconductors, e.g. CoSi₂ or GaAs/Ga_1-xAl_xAs, are the most practically fabricated in the form of planar structures. Moreover, it is well adapted for various gate electrode geometries for activation and control of the quantum wells.

A Fiber Optic Pressure Sensor utilizing a Fiber Bragg Grating (FBG) as a sensing element has been demonstrated. In the experiment, a broad band LED source with a wavelength range of 1520 nm to 1570 nm was launched into a single mode optical fiber within which the FBG was written. With no applied force, the fiber grating reflects light strongly at a wavelength of 1549.92nm. When the FBG was subjected to a range of forces (from 0.0N to 18.0N), applied perpendicularly to its axis, the reflected light from the FBG was found to be wavelength shifted in proportion to the applied force, but in a non- linear manner. The shift in wavelength is detected using fiber Fabry-Perot interferometric technique. With the FBG embedded in carbon fiber material, the test results showed an excellent linear relationship between the wavelength shift and the applied force (pressure). In addition, force sensing range of up to 60N was obtained with the pressure sensor still remaining in good condition.

Recently much success has been achieved in the field of dielectric interference coatings. However, the appearance of new types of lasers (for example, diode-pumped solid-state lasers) required development of the high quality low loss coatings for various spectral regions. These coatings may be divided into two groups, antireflective coatings and cut-off filters. We have investigated the various aspects of these coatings. There are choice of the optimum construction of the optical coatings to obtain the required parameters in the specific spectral region, development of the production process to obtain the reproducing results when assembling lasers, study of optical parameters. As a result, the technology for making the following coatings has been developed: (1) the AR coatings for Nd:YAG crystals with the coefficient of residual reflection ((rho) ) less than 0.1% of one surface at 1.06 micrometer; (2) the AR stable coating for LiJO₃ crystals with the same parameters; (3) the AR coating for KTP crystals with (rho) less than 0.1% of one surface at 1.06 and 0.53 micrometer simultaneously; (4) the AR coating for the BK-7 substrates with (rho) less than 0.3% at 0.809 and 0.53 micrometer simultaneously; (5) the cut-off filter for the BK-7 or Nd:YAG crystal with high reflection (HR) greater than 99.9% at 1.06 micrometer and high transmission (HT) greater than 95% at 0.809 and 0.53 micrometer; (6) the cut-off filter with HR greater than 99.9% at 1.34 micrometer and HT greater than 95% at 0.67 micrometer; (7) the cut-off filter with HR greater than 99.9% at 1.08 micrometer, HR greater than 90% at 0.53 micrometer and HT greater than 85% at 0.355 micrometer. All types of the optical coatings have been tested in the assembly of the lasers. Now these coatings are successfully used in the commercial lasers.

The linewidth enhancement factor is the crucial design parameter with others, such as gain and refractive index changes for semiconductor laser diodes (LD). The changes of characteristics are measured according to the variation of the thickness of SCH (Separate Confinement Heterostructure, 1.24 micrometer p-InGaAsP). The gain spectra were obtained from the spontaneous emission for three LD's. The threshold current; I_th were about 15 mA. The optical field profiles for various SCH thickness was calculated from the effective index and transfer matrix method and the corresponding optical confinement factors are compared with the variation of measured (alpha) . It is meaningful to find the SCH thickness, SCH_(Gamma max), of maximum confinement (Gamma) for given LD structure. Although the improvement of the linewidth enhancement factor ((alpha) ) in thicker SCH (greater than SCH_(Gamma max)) has been known, it has not been measured for thin SCH (less than SCH_(Gamma max)). Here, we compare the measured linewidth enhancement factors of three DFB-LD's with different SCH thickness of 500, 750, and 1000 angstrom, which are all smaller than the SCH_(Gamma max) for given structure. It is shown that (alpha) would be improved as SCH thickness increases up to 1500 angstrom (approximately SCH_(Gamma max)) for given structure if other design parameters permit.

The objective of this research program was the development of the technology for the industrial manufacturing of HOEs for technical applications such as: holographic solar concentrators for utilization in photovoltaic energy conversion and solar photochemistry, and integrated holographic stacks for daylighting, glazing and shading in buildings. Some of the fabricated HOEs exhibit apertures in the order of 8 square meters. The accomplished technology facilitates the continuous fabrication of the holographic films on glass or plastic substrata. The standard holographic material we use for the fabrication of HOEs is dichromated gelatin (DCG) on glass or plastic film (PET) substrata. The dichromated gelatin layer could be prepared with different compositions to accommodate the desired exposures and chemical processing procedures. At present we manufacture holographic plates on glass substrata in sizes of up to 1 meter square. The holographic film on plastic substratum is 20 cm wide and could be made in lengths of hundredths of meters. The inexpensive fabrication of such large formats is attained by automation of the entire process: film manufacturing, hologram copying, development and test. We present in this paper the design considerations and the developed manufacturing procedures. These comprise the fabrication of large format reflective holograms for concentrating mirrors and the copying of transmissive holograms, such as gratings and lenses, using in-plane contact copying in checkerboard arrangement or rotating drum continuous copying onto an endless plastic film.

This paper is devoted to the analysis of the optical performance of movable-beam grating structures with both lateral and vertical displacement of the beams. We show that in the vector-diffraction domain one can design high- efficiency switches (e.g. between beam transmitter and beamsplitter mode) and modulators for polarized radiation. The devices exhibit a good tolerance to fabrication and mounting errors and a functional flexibility. In addition, by simulating the optical performance of polysilicon micro- electro-mechanical grating structures at a visible wavelength, reported in the literature, we demonstrate that our tools for rigorous electromagnetic simulation of grating structures work well in the scalar-diffraction domain.

The 2-Axis pointing mechanism which we developed is designed for earth observation system. This pointing mechanism is expected to work on the geostationary orbit with high resolution compare with former one. To achieve high resolution, we adopted optical heterodyne technique to mirror angle detecting sensor instead of rotary encoder. The angle of the mirror is calculated from the distance between mirror base and a certain point of reverse side of the mirror. We can get the resolution of 0.029 (mu) rad. For mirror driving mechanism, we adopted a crank mechanism because a pointing mechanism working on the geostationary orbit is not necessary to rotate whole angle. We can get about 1:10 reduction ratio with a crank mechanism in addition to the reduction gear attached to the motor shaft. We have made experimental model and validated its performance.

A new design of diffractive superresolution elements with surface-relief phase screen has been presented to improve the quality of the superresolved diffractive patterns. The diffractive phase screens have been designed by our proposed global optimization method, called Global/Local United Search Algorithm. The new algorithm combines the global exploration properties of Genetic/Annealing algorithms and the accurate exploitation power of the 'hill-climbing' method, resulting in the characteristics of fast convergence, global search capability, and high performance diffractive patterns. The designed diffractive phase screens can improve the performance of the superresolved diffractive patterns from the view of Strehl ratio, reduction of the focal spot, and control of the sidelobe intensity. The results show that the diffractive phase screen can produce much small spot size and great lower sidelobe intensity while keeping an acceptable Strehl ratio, which has important applications in high density data storage.

A new device for displaying ordinary transmission holograms with a white light source is described, based on compensating the dispersion in a broad band of the visible spectrum. Using the device, the clear image from the ordinary transmission hologram plane have been reconstructed.

In this paper we describe the design of a reflective/diffractive hybrid optical system, which features no obscuration, imaging system with 100% cold shield efficiency, 4 degrees of field of view, near diffraction limited imaging quality, and working in the long wavelength infrared (LWIR) region of 8 - 12 microns.

We report the design and fabrication of Hybrid Dichroic Mirrors (HDM) for the separation and the recombination of white laser beam by using small sized flat plate for a small Laser Projection Display (LPD) system. This small sized laser projection display system is consist of a white laser, hybrid dichroic mirrors, 3-channel AOM and a beam scanning part. Red, green and blue light beams are separated by one flat plate dichroic mirror and also modulated by the 3-channel AOM, are recombined to one beam by another flat plate dichroic mirror. These hybrid dichroic mirrors are designed to measure the separation and recombination of s-polarized light beams of 647, 515, 488 nm wavelength from the white laser. Key element of the mirror design includes the quarter wavelength multilayers optimized to provide the best performance for the separation and recombination of light beams. The calculated values of the transmittance, which are pass through the hybrid dichroic mirror, are 95% for each separated/recombined color beams. The measured values of transmittance are over 90%.

A small laser projection display system is designed with a hybrid dichroic mirror for color separation, a hybrid dichroic mirror for color recombination, a 3-channel acousto-optic modulator (AOM) and a scanning part. The 3-channel AOM modulates red, green and blue laser beams. The wavelengths of red, green and blue beams are 647, 515 and 488 nm respectively. The carrier frequencies of each channel of AOM were adjusted to minimize the diffraction angle differences among red, green and blue laser beams. The carrier frequencies are 130, 168, 178 MHz for red, green and blue laser beams respectively. The measured diffraction angle after the carrier frequency control equals to the calculated diffraction angle. The transducer structure of AOM was optimized to get a high diffraction efficiency and to maximize isolation between adjacent channels by a slicing saw, which enhanced the electrical and acoustic isolation. The impedance matching- circuit of each electrode is housed in a separate compartment to suppress electrical crosstalk. The diffraction efficiency and risetime of the 3-channel AOM are over 85% and 50 nsec per each cell. The crosstalk between the channels is less than -30 dB.

This manuscript presents multiple modeling efforts to describe diffraction of monochromatic radiant energy passing through an aperture for use in the Monte-Carlo ray-trace environment. Described is a deterministic model, based upon Heisenberg's uncertainty principle, which predicts the angle at which an approaching ray is diffracted. The result is a curve which approximates the analytical interference pattern, but does not model the side fringes (i.e. secondary maxima). This model is applicable to either Fraunhofer (far-field) or Fresnel (near- field) diffraction situations. In addition to this model, a diffraction model is presented that approximates the interference pattern including the secondary maxima, as produced by radiation passing through a slit or a circular aperture. This model, based on the Huygens-Fresnel principle with a correcting obliquity factor, is useful for predicting Fraunhofer (far-field) diffraction in the Monte-Carlo ray- trace environment. The motivation for this work is the need to properly model the diffraction of radiant energy as it approaches a detector intended for monitoring the Earth's radiation budget from a geo-stationary orbit. The proposed detector, a linear-array of thermopile elements, is housed in a wedge-shaped cavity with a 60-$micrometer slit through which radiant energy between wavelengths of 0.1 micrometer and 40 micrometer must pass. A radiative model of this cavity which does not account for diffraction effects has already been developed using the Monte Carlo ray-trace method. This detector was originally intended to fly on the Geo-Stationary Earth Radiation Budget (GERB) instrument.

A high power He-Ne laser, including two laser tubes having rectangular discharge cross-section and giving about 350 mw total output power, has been designed and elaborated. The laser beams can be coupled into a quartz optic fiber by optical system. This laser has been applied to photodynamic therapy (PDT) for cancer. Its complete response rate is about 60% in 44 clinical cases. In this paper, the design principle and the experimental results of this high power He-Ne laser and its patient response of PDT for cancer are introduced. In addition, the curalive effects of PDT using different lasers are also discussed.

A polarizer which works upon the combination effect of birefringence and diffraction has been designed and realized experimentally. According to the design the polarizer may be consisting of a sheet of birefringent material or two birefringence plates, on which surface one dimensional grooves with a sawtooth profile or echelon profile are carved. In experiment, a periodic grooves of a sawtooth profile were fabricated on the surface of calcite plate by mechanical and optical manufacture techniques. This sample polarizer was test for its polarized feature with a non-polarized HeNe laser, and the results show the polarizer is of a good polarized performance.

The purpose of this paper is to introduce the concept of a Locking Lorentz Slide. Lorentz Slide actuators, which are based on the Lorentz force principal of physics and are also called Voice Coils, have earned wide-spread use in the aerospace industry because of their superior performance (precision, force, stroke, wide temperature range including cryogenics, reliability and compactness). NASA has particularly favored these devices in their space telescopes and scientific instruments. Up to now 'Voice Coils' have had to keep power on to hold position, which is limiting in many space applications. NASA, however, has found what promises to be a simple, innovative work-around with its Locking Lorentz Slide approach. This paper is an introduction to that concept and its possibilities, so, in this paper, the Locking Lorentz Slide is described, its principles of operation explained an its expected performance given. Since NASA is embarking on a development effort for this actuator more technical papers detailing hardware, tests and detailed analysis will follow.

A new NGST Inchworm^R motor design is described that meets the demanding actuator requirements of the Next Generation Space Telescope. The classic Inchworm motor does not function at cryogenic temperatures. The interference fit between the motor and shaft gets tighter and breaks the clamps and 80 percent of piezoelectric (PZT) movement is lost at 20 degrees K. The NGST Inchworm concept maintains a constant fit over a wide temperature range and the loss of PZT motion is compensated for by adding extra PZT material or potentially by incorporating new cryogenic active materials that are currently being developed by other companies. Another significant improvement of the NGST Inchworm is the ability to hold position when power is removed (i.e. zero charge on all actuators) with zero PZT creep. This makes it possible for the NGST Inchworm and electronics to dissipate zero power when holding position for days or weeks. The NGST Inchworm will have a new clamp design that has at least ten times lower clamp 'glitch' than the classic Inchworm. Low clamp glitch makes it possible to move to a desired position with nanometer resolution and deactivated the motor without disturbing the output position more than a few nanometers.

Alson E. Hatheway Inc. and Moog-Schaeffer Magnetics Division have been developing a new class of structural actuators for use in optical instruments. The actuators feature large stroke (.1 millimeter or more) and high resolution and repeatability (10 nanometers or less) with the strength, stiffness and safety of the structural engineering metal alloys. The actuators use patented elastic transducers to achieve very high resolution and repeatability (better than 10 nanometers) and are driven by electrical stepper motors which provide remote operation and digital control.) One application for the actuators is the Next Generation Space Telescope (NGST) which is one of the programs in NASA's Origins Mission.

A generic vibratory-response modeling program has been developed as a tool for designing high-precision optical positioning systems. The systems are modeled as rigid-body structures connected by linear nonrigid elements, such as complex actuators and bearings. The full dynamic properties of each nonrigid element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Thus, it is possible to have a suite of standardized structural elements for modeling many different positioning systems that use standardized components. This paper will present the application of this program to a double-multilayer-monochromator positioning system that utilizes standardized components. Calculated results are compared to experimental modal analysis results.

Force actuators used for vibration control, such as shakers and proof-mass actuators, typically use single-phase electromagnetic linear motors that have a range of travel limited to a few inches. For proof-mass actuators, the stroke limitation can be especially constraining because it also limits the force output of the actuator at low frequencies. To overcome this low output at low frequency, we have developed an inertial, long stroke, linear actuator (ILSLA). The ILSLA is built around a three-phase linear motor that is driven by a commutating amplifier to achieve strokes of almost unlimited length. Vibration control applications that can benefit from this technology include precision space structures and large- scale robots.

An electromagnetic Lorenz force transducer has been coupled to an Angstrom ^tm elastic transducer to form a new compound transducer in which the displacement output is proportional to the current input. It is called HECTOR and has been built in a form which provides very small displacements (in the range of nanometers) in response to modest currents (tens of milliamperes). The transduction effect is shown to be linear and hysteresis-free which provides for accurate calibration of the transducer and highly repeatable performance. HECTOR is intended to generate reliable and repeatable small displacements, smaller than may be obtained by the subdivision of the wavelength of light, for use in the calibration of metrology instruments which may be used in surface metrology, process control and research. This paper describes the operation of HECTOR and its use in the setup and validation of an interferometric metrology facility to be used to measure small displacements.

A novel laser Doppler linear encoder system (LDLE) has been developed at the Advanced Photon Source, Argonne National Laboratory. A self-aligning 3-D multiple-reflection optical design was used for the laser Doppler displacement meter (LDDM) to extend the encoder system resolution. The encoder is compact [about 70 mm(H) X 100 mm(W) X 250 mm(L)] and it has sub-Angstrom resolution, 100 mm/sec measuring speed, and 300 mm measuring range. Because the new device affords higher resolution, as compared with commercial laser interferometer systems, and yet cost less, it will have good potential for use in scientific and industrial applications.

In the process of designing a control actuator for a vibration cancellation system demonstration on a large, precision optical testbed, it was discovered that the support struts on which the control actuators attach could not be disassembled. This led to the development of a Linear Precision ACTuator (LPACT) with a novel two piece design which could be clamped around the strut in-situ. The design requirements, LPACT characteristics, and LPACT test results are fully described and contrasted with other earlier LPACT designs. Cancellation system performance results are presented for a 3 tone disturbance case. Excellent results, on the order of 40 dB of attenuation per tone (down to the noise floor on two disturbances), are achieved using an Adaptive Neural Controller (ANC).

This paper introduces a new type of reflector mount array, which is designed for main amplifier of ICF Laser Driver in China. The whole system utilizes a special array structure, in compliance with the requirement of a small distance among each beam of the laser system. The one-body joint drive structure and a flexible structure ensure the system with high adjusting accuracy and stability. In addition, according to the characteristic of this system, the paper calculates the turning angle and accuracy of the flexible, which shows that the theoretical accuracy can reach 0.017', and the experiment results confirm this accuracy. The transmission error of one- body joint drive structure is analyzed in detail, and Finite Elements Method is used to optimize the support structure in order to lessen the deformation of the reflector.

A Finite-Difference Method in Non-Orthogonal Curvilinear Coordinate System (FDM-NOCCS) is the combination of the domain transformation technique and the Finite-Difference Method (FDM). It has the visualization and simplification of the traditional FDM. On the other hand, it overcomes the weakness of FDM in dealing with complicated boundary shapes, averts the interpolation between the grid points in the vicinities of boundaries, and also avoids the abnormalism in the transformation from the physical domain to the computational domain. The FDM-NOCCS is used in the computer aided design of electron gun for color cathode ray tube. Compared with the formal FDM, the FDM-NOCCS can save quite a lot of CPU time and computer memory. FDM-NOCCS works well with the complicated e- gun systems design.

In this article, we present a laser far-field CCD diagnostic device, which consists of optical system with (Phi) 250 mm aperture, the CCD image receive system connecting with a computer and a single pulse synchronous trigger system. The collected images are processed and displayed in real time by computer. A quasi-ideal plane wave at 1060 nm is used to test the characters of this diagnostic device. The experimental result shows that size of focal spot encompassing 70% laser energy is about 2.5 times of diffraction limit. The device has been successfully applied to high power laser facility. According to the practical measurement, the far-field divergence angle is less than 14 times of diffraction limit when output of high power laser facility is 200 J each beam.