This PDF file contains the front matter associated with SPIE Proceedings Volume 8486 including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

The purpose of this investigation is to understand the causes and implications of centroid distortion in the LORRI instrument on the New Horizons spacecraft. First, an introduction to the New Horizons space program is provided, and the design specifications of the LORRI telescope are discussed. Next, a general theory of perfect imaging is presented, with emphasis on the paraxial equations for the transfer of the chief ray, and the shape of the diffraction-limited point spread function (PSF). Centroid distortion is then defined with respect to these quantities, and methods for quantifying centroid distortion are explained. The nominal LORRI design is analyzed, and the centroid distortion predicted by the nominal design is shown. Astrometric reduction is then performed on a set of twenty in-flight LORRI images, and the actual centroid distortion of the telescope is modeled. Finally, Monte Carlo tolerancing techniques are used to attribute the differences between the predicted centroid distortion and the in-flight centroid distortion to a set of specific manufacturing tolerances.

FORMOSAT-5 is the first space program that National Space Organization (NSPO) takes full responsibility for the complete satellite system engineering design including payload(s). FORMOSAT-5 will operate in a sun synchronous orbit at 720-km altitude with 98.28-degree inclination angle. The optical Remote Sensing Instrument (RSI) can provide 2-m resolution panchromatic and 4-m resolution multi-spectral images. A Cassegrain type of RSI with two reflective aspheric mirrors and spherical corrector lens is designed. The space thermal environment is one of the important factors that affect the image quality of a space optical RSI. Thermal deformation of RSI structure and mirrors will impact the optical performance. Some preliminary thermal and opto-mechanical analyses are conducted. The relationship among temperature distributions, thermal deformations and image degradation of on-orbit behaviors are discussed. The thermal induced instabilities are incorporated in optical models (e.g., OSLO) by use of Zernike polynomial coefficients to calculate the system MTF and WFE. Due to different thermal environments, on-orbit optical performances depend on imaging locations. Detailed studies and discussions are done in this paper to identify the major sources of thermal deformations and their impacts on image quality.

The Cassegrain telescope system in this study, is discussion correct lens thermal OPD (Optical Path Difference) effect optical performance. The correct lens assembly are includes several components such as correct lens, lens mount, spacer, mount barrel and retainer. The heat transfer from surrounding to the correct lens barrel will causes optical system aberration. Meanwhile, the off-axis rays path of the OPD must consider lens incidence point and emergence point. The correct lens temperature distribution is calculate the lens barrel heat transfer analysis, the thermal distortion and stress are solve by FEM (Finite Element Method) software. The temperature calculation results can be weighting to each incidence ray path and calculate thermal OPD. The thermal OPD on Z-direction can be fitted by rigid body motion and Zernike polynomial. The fitting results can be used to evaluate the thermal effect on correct lens assembly in telescope system.

Staring infrared imagers have multiple surfaces within the integrated Dewar assembly which contribute to non-traditional Narcissus artifacts. Static non-uniformity correction is insufficient to remove dynamic Narcissus artifacts caused by moving focus or zoom groups. Dynamic Narcissus artifacts often manifest as rings apparent to the human eye, although they may lie near the noise floor of the imager. Moreover, strong field curvature of the Narcissus can complicate diagnosis using paraxial methods. We compare a simple pupil ghost metric to traditional Narcissus metrics and present an experimental case study illustrating how the metric can be used during optimization to eliminate the effect.

Freeform surfaces provide more degrees of freedom for design of optical systems, and enhance the ability of compensation and correction aberrations. Freeform surfaces are of advantage to balance the unsymmetrical aberrations, especially for the wide-field off-axis optical systems. This paper focus on an off-axis reflective optical system, which focal length is 550mm, F# is 6.5 and field of view (FOV) is 76°. The system adopts some freeform surfaces. We discuss the problems we noticed in processes of design, manufacture, measurement and alignment, and the solutions. At last, the periodical research result and the expected performance are given.

A new three-dimensional analytic optics design method is presented that enables the coupling of three ray sets with only two free-form lens surfaces. Closely related to the Simultaneous Multiple Surface method in three dimensions (SMS3D), it is derived directly from Fermat’s principle, leading to multiple sets of functional differential equations. The general solution of these equations makes it possible to calculate more than 80 coefficients for each implicit surface function. Ray tracing simulations of these free-form lenses demonstrate superior imaging performance for applications with high aspect ratio, compared to conventional rotational symmetric systems.

This paper describes our experience with global lens optimization using algorithms that can modify an existing lens construction in an optimal way or create an entirely new construction. The binary-search method assembles lens elements according to the bits in a binary number, ensuring that all combinations of power are tested, while the saddlepoint method can either add elements to a starting lens or start from scratch. The latter algorithm also naturally leads to a method of removing an element in an optimum way, which can sometimes simplify a lens with no loss of quality.

Understanding the structure of the design space in optical system optimization is difficult, because common human intuition fails when it encounters the challenge of high dimensionality, resulting from the many optimization parameters of lens systems. However, a deep mathematical idea, that critical points structure the properties of the space around them, is fruitful in lens design as well. Here we discuss simple systems, triplets with curvatures as variables, for which the design space is still simple enough to be studied in detail, but complex enough to be non-trivial. A one-to-one correspondence between the possible design shapes and the critical points resulting from a simplified model based on third-order spherical aberration within the framework of thin-lens theory could lead in the future to a new way to determine good starting points for subsequent local optimization.

We introduce a novel application of reflective axicon surfaces to high performance image-forming objectives. The reflective surfaces are arranged such that the optical and mechanical axes are collinear, yet have the potential to provide unobscured transmission. Offering the ability to compete with the performance of traditional diffraction-limited unobscured optical systems provides a design and fabrication alternative where demanding optical requirements must be met. There are four possible arrangements for construction, with the two outer reflectors always being concave and the two inner reflectors being either concave or convex. Multitudes of novel design forms are explored. We describe monolithic and two-piece solid, two- and three-piece reflective, and two-piece hollow-solid hybrids. We analyze the performance of such designs and compare to the performance of both refractive and reflective systems.

The paper presents the mathematical description of an optical microscope with a digital camera and an image processing as an analog-digital-analog imaging system. This description considers a channel of the microscope as a sequence of the linear spatial filters of two dimensional signals. The channel contains an optical system as a low frequency analog filter, a digital camera as a low frequency analog filter with spatial and amplitude discretization and noise generation, a digital linear filter which has to amplify the high frequency harmonics and a restoration unit that plays a role of a two dimensional interpolator. This mathematical apparatus is useful for proper selection of a digital camera which guarantees the maximal field of view with absence of image distortions. The terms like optimal, nonsufficient and non-useful (void) linear magnification of a microscope optical system are expanded from a visual microscopy to a digital one. This mathematical description is also applied for selection of a digital filter for focusing and digital focus extension. The modulation transfer function of this filter should match for the spatial spectrum of observed objects in the zone of spatial harmonics that is most sensitive to defocusing. In this case the maximal sensitivity to defocusing with minimization of influence of noise can be reached.

This paper will demonstrate a graphical method for selecting a pair of optical components to simultaneously achromatize and passively athermalize an imaging lens for use in a housing with a particular coefficient of thermal expansion. The effort will be presented for a generic spectrum, so readers may apply the method to whatever waveband and set of materials that are of interest. The term “component” is used in place of “material” since this paper will explore combinations of refractive and diffractive optics. The method for creating an achromat with two refractive materials will be reviewed. To create an athermal doublet, or lens that does not change focus under temperature changes, the same color equations are used with a slight modification to include housing thermal effects. The paper will culminate by demonstrating how a set of two materials can be used to both color correct and passively athermalize a single lens; these materials can be quickly chosen to match a particular housing material via nomograph. A sample chart for a common waveband will be demonstrated.

A zoom objective lens for a multi-layer optical recording has been designed. A newly proposed optical power arrangement enables varying back focal length while focal length invariant by a linear movement of single zooming component. The zoom lens is implemented into multi-layer and multi-bit holographic recording system employing 405 nm blue lasers.

The NASA Interface Region Imaging Spectrograph (IRIS) mission is a Small Explorer (SMEX) satellite mission designed to study plasma dynamics in the “interface region” between the Sun’s chromosphere and corona with high spatial, spectral, and temporal resolution. The primary instrument is a dual Czerny-Turner spectrograph fed by a 20-cm Cassegrain telescope measuring near- and far-ultraviolet (NUV, FUV) spectral lines in the ranges 133-141 nm and 278- 283 nm. To determine the position of the slit on the solar disk, a slit-jaw imaging system is used. The NUV slit-jaw imaging system produces high spatial resolution images at two positions in the Mg II 280 nm spectral line complex using a birefringent Solc filter with two wide-band interference pre-filters for spectral order selection. The Solc filter produces a 0.36 nm full-width at half-maximum (FWHM) filter profile with low sidelobes and a peak transmission of 15% at 279.6 nm. The filter consists of two “wire grid’’ polarizers surrounding 8 quartz waveplates configured in a modified Solc “fan” rotational pattern. The elements are optically coupled using DC200 silicon-based grease. The NUV Solc filter is sealed in a windowed cell to prevent silicon contamination of the FUV channel. The design of the sealed cell and assembly of the filter into the cell were among the most challenging optomechanical aspects of the IRIS spectrograph system.

A head-up Display, HUD, is a safety feature for automobile drivers. Although there have been some HUD systems in commercial already, their images are too small to show assistance information. We demonstrated a HUD including micro-projectors, rear-projection screen and a Fresnel lens and realized a 14 inches image on the windshield. It is able to show speed, map-navigation and night vision information. We adopted digital light processing, DLP, as our image source because of its brighter image output required. To minimize the model volume, we applied a Fresnel lens to magnify the images from DLP projector. The size of the HUD model is 390 mm × 274 mm × 117 mm. It shows a virtual image 1.5 meters from windshields and the brightness is 378 nits which is clear enough to be seen by drivers even during daytime. Besides, it can also display information on a 7 inches instrument panel simultaneously.

Optical designs in various applications profit from the increasing use of freeform elements. However, freeform optics always challenges the manufacturing process. The complexity of the fabrication derives from the missing symmetry in freeform surfaces. Ultra-precision machining is an appropriate method to realize complex optical freeforms. Surface deviations can be reduced in a deterministic process by a test and correction loop to achieve shapes with sub-μm deviations. But freeform elements do not only require the optical performance, they also depend on tight tolerances of the surface position with respect to reference structures. Due to the absence of rotation symmetry in freeform elements, all six degrees of freedom have to be constrained. Diamond machining allows to machine reference structures on the optical part. They can be used for alignment while testing or during the assembly processes. This paper shows a deterministic approach to manufacture optical freeform surfaces with sub-μm surface deviations by fly-cut-machining and servo assisted diamond turning. Reference structures are included at the edge of the element in order to support the following measurement and assembly processes. The reference structures are manufactured within the machining process of the optical surface. This procedure ensures tight tolerances between reference structures and optical surface /1/. The complex optical surface is measured with respect to the references with the tactile measurement system UA3P. The reference structures are used to locate the coordinate system of the element and hence to constrain the alignment parameter. After fitting the data, a revised tool-path is used to improve the shape deviation to sub-μm accuracies.

Air-driving fluid jet polishing (FJP) technique was first presented in 2011. Slurry was drop out due to Venturi effect inside the atomizer which is the main component of air-driving FJP system, and was guided to mix with air flow by the nozzle. The Venturi effect and the added high speed air flow provide slurry more kinetic energy to impact the optical surface. Therefore, the air-driving FJP system has a rotational symmetrical Gaussian-like removal profile with lower air pressure and normal incidence configuration. In this paper, we investigate oblique incidence polishing to find the optimal material removal performance of the technique, including removal shape and depth and surface roughness. Different oblique angles ranged from 80 to 20 degree were tested. The air-driving FJP system was adapted upon a CNC machine, so not only single point polishing but also straight line polishing with constant feed rate can be carried out. We report on the performance of oblique air-driving FJP in different air pressure and processing time, and also the material removal of dynamic polishing for N-BK7, Fused Silica and ZERODUR®. The results indicate oblique incidence can get a Gaussian-like removal shape, and improve the surface roughness. The air-driving FJP not only has the advantages of conventional fluid jet polishing, such as no tool wears, cutter interference and debris deposition problems, but also has excellent material removal rate with lower energy.

We incorporated ultrasonic vibration into recently developed fixed-abrasive pellets in an attempt to enhance MRR and/or to improve manufactured surface quality. A prototype ultrasonic vibrator, the heart of the polishing head, was designed and the related experimental work was performed on an in-house built setup in conjunction with the constructed head. The vibrator is devised for the generation of 2-D tool path despite using only one actuator in lieu of two actuators in conventional 2-D ultrasonic machining systems. We then combined the ultrasonic vibration with fixed abrasive polishing pellets to machine fused silica glass. Machining experiments reveal that MRR is considerably increased up to <50% upon the introduction of ultrasonic vibration (UV) whilst surface roughness is not degraded appreciably.

Diamond reinforced reaction bonded silicon carbide composites have unique properties such as very high stiffness, low density, low thermal expansion coefficient and high thermal conductivity making them attractive materials for high precision optical and structural components. However, their use in high precision equipments was limited due to significant difficulties in high tolerance machining of these super hard composites. In this present work, machineable diamond reinforced SiC composites were fabricated through forming hybrid monolithic microstructures with diamond free machineable surfaces. The resulting machineable composites were used to produce ultra-stable mirror substrates with optional internal cooling channels for high power laser optic applications.

Each mirror produced by this NASA developed process is a monolithic structure from a single crystal of silicon. Due to single crystal silicon's extraordinary homogeneity and lack of internal stress, we light weight after optical polishing. Mirrors produced by our original process were about 1/4th the mass of an equivalent quartz mirror and were typically 1/50th wave or better. We have recently revised our process, replacing the isogrid structures with ones optimized to minimize distortion due to mounting errors. We have also switched from ultrasonic machining to CNC grinding to enable the production of larger mirrors. We report results to date for mirrors produced by the revised process and cryogenic test results for an ultrasonically light weighted mirror.

In this study, the measurement of a 160 mm convex hyperbolic mirror by using the 6 inches phase shifting interferometer and the CGH (computer-generated hologram) in a vertical setup is presented. The wavefront errors of the metrology system including the reference flat and CGH flat due to gravity effect are measured and calibrated by using random testing and null cavity testing with and without CGH. Then, the real form error of each single sub-aperture could be acquired by subtracting the system wavefront errors. In this study, we measured form errors of 10 off-axis sub-apertures with equal angle space and then stitched them to establish the whole irregularity in the shape of the mirror in 160 mm diameter. Finally, we imported the irregularity in the shape of the mirror to the CNC aspheric polishing machine for correction polishing. Combining the aspheric metrology technique and the CNC aspheric polishing technique, a 160 mm secondary mirror for the Cassegrain reflecting system was finished within PV 0.15μm and RMS 17.9 nm.

A methodology analogous to a general lens design rule was proposed to step-by-step optimize the spectral power distribution (SPD) of a composite light-emitting diodes (LEDs) cluster. The computation is conducted for arbitrary SPD combination for the applications in radiometry, photometry and colorimetry, respectively. Based on the matrix computation, a spectrally tunable source is implemented to strategically manipulate the chromaticity, system efficiency and light quality according to all kinds of operational purposes. By the R/G/B/A/CW light engine with graphic utility interface, the cluster engine was experimentally validated to offer a wide-ranged operation in ambient temperature (T_a = 10°C to 100°C) with high color quality scale (CQS < 85 points) as well as high luminous efficiency (LE < 100 lm/watt) over the chromaticity point from 2800K to 8000K.

A solid state light source provided for wavelength multiplex 3D Display is proposed. The system of solid state light source includes blue laser arrays of two wavelengths, a 2-ring phosphor wheel, a multi-band filter and a TIR prism. Green and red phosphors excited by blue lasers provide the original green and red lights of wide bandwidth. By passing through or reflected by a multi-band filter, two groups of green and red lights of narrow bandwidth for left or right eyes are selected. Blue lasers of two wavelengths also provide two blue lights for left and right eyes. Instead of using a second rotated narrow band filters that synchronized with the first phosphor wheel, a wheel having two rings coated with mirrors and phosphors is used to replace the synchronization existing in the conventional two wheels method. After passing the 2-ring wheel, the light source switches between two light paths that lead to be reflected or transmitting through the multiband filter. The multi-band filter can be disposed in a telecentric optical path to secure a high efficiency for the filter. A compact spectral multiplex light source is realized and can be directly attached to any existing optical engine.

A novel light luminaire is proposed and experimentally analyzed, which efficiently mixes and projects the tunable light from red, green and blue (RGB) light-emitting diodes (LEDs). Simultaneous light collimation and color mixing is a challenging task because most collimators separate colors, and most color mixers spread the light beam. We performed an experimental study to find a balance between optical efficiency and color uniformity by changing light recycling and color mixing.

Based on Monte Carlo ray tracing we present a study of GaN die with a reflective layer coated on a p-GaN surface inside the light guide as a planar light source. We simulated the lights extracted from the GaN die implanting pyramid microstructure on the top surface of sapphire or on the top surface of p-GaN. Micro pyramid array with different slanted angle from 5⁰ to 85⁰ is shown to effectively improve the light extraction efficiency. In addition, the pattern sapphire substrate with slanted angle of ten degrees is found to be an effective way to increase the lateral directionality than the surface texture.

In multiscale imagers a single objective lens is shared by multiple secondary optical systems, so that a high-resolution wide-angle image is acquired in overlapping fields sensed by multiple conventional focal planes. In the “AWARE2” 2 Gigapixel imager, F/2.4 optics cover a 120 degree field of view using a monocentric glass primary lens shared by 221 molded plastic subimagers, each with a 14 Megapixel focal plane. Such imagers can independently focus parts of the image field, allowing wide-angle imaging over relatively close and deep image fields. However, providing hundreds of independent mechanical focus adjustments has a significant system impact in terms of complexity, bulk, and cost. In this paper we explore the use of an electronically controlled liquid crystal lens for focus of multiscale imagers in general, and demonstrate use with the AWARE2 imager optics. The Lens Vector Auto Focus (LVAF) liquid crystal lens provides up to 5 diopters of optical power over a 2.2mm aperture diameter, the maximum currently available aperture. However, a custom lens using the same materials and basic structure can provide the 5 diopters power and 6.4 mm aperture required to obtain full resolution overlapping image fields in the AWARE2 imager. We characterize the LVAF lens and the optical performance of the LVAF lens in the current AWARE2 prototype, comparing the measured and optically modeled resolution, and demonstrating software control of focus from infinity to an 2m object distance.

This paper presents a tunable liquid lens based on microelectrofluidic technology which integrates electrowetting and microfluidics. In the novel microelectrofluidic lens (MEFL), electrowetting in the hydrophobic surface channel induces the Laplace pressure difference between two fluidic interfaces on the lens aperture and the surface channel. Then, the pressure difference makes the lens curvature tunable. The previous electrowetting lens in which the contact angle changes at the side wall has a certain limitation of the curvature variation because of the contact angle saturation. Although the contact angle saturation also appears in the surface channel of the MEFL, the low surface channel increases the Laplace pressure and it makes the MEFL to have full variation of the optical power possible. The magnitude of the applied voltage determines the lens curvature in the analog mode MEFL as well as the electrowetting lens. Digital operation is also possible when the control electrodes of the MEFL are patterned to have an array. It is expected that the proposed MEFL is able to be widely used because of its full variation of the optical power without the use of oil and digital operation with fast response.

The opportunities of film deposition by means of microwave plasma using plasma enhanced chemical vapor deposition (PECVD) will be discussed and the necessary process equipment presented. The AK series of MicroSystems GmbH is a platform for processing single substrates and is suitable for a variety of high-end applications. One possible application, the generation of passivation layers in the production of edge emitting diode lasers, is presented and discussed. By means of this application, the advantages of microwave plasmas are highlighted.

The “m-lines” guided mode method has been employed as a new approach to measure the penetration depth of UV light in partially exposed thin film photoresist layers. This non-destructive method presents the advantage that the penetration depth can be measured before developing the sample, allowing for fine tuning of exposure parameters. Results are presented for a positive photoresist (Shipley S1813) deposited by spin coating onto glass slides, forming layers approximately 2.2μm thick. Such films are exposed to varying degrees with a programmable UV exposure tool. Using the “m-lines” technique, light is coupled into the photoresist samples using a prism coupler in close proximity to the sample surface. This coupling occurs for specific incident angles, known as synchronous angles, which depend on the sample structure. By measuring two such incident angles, one can calculate the thickness and refractive index of a homogeneous film. We propose a two layer model which allows us to extract the thickness and the refractive index of the upper exposed layer from the synchronous angles provided by the “m-lines” technique.

New approaches for optical data storage (ODS) applications are needed to meet the future requirements of applications in multimedia, archiving, security, and many others. Commercial data storage technologies are moving to threedimensional (3D) materials, but the capacity is limited by the fabrication cost and the number of layers that can be addressed using the reflection-based storage mechanism. We demonstrate here storage systems based on co-extrusion of multilayer (ML) films that can overcome these problems. The organic roll-to-roll films produced can easily be produced hundreds of meters in length, in a far simpler and cheaper manner than current manufacturing methods such as spin coating and lamination. The medium consists of alternating active and buffer layers, and data storage is demonstrated by writing images in 23 layers of 78 μm thick films by fluorescence (FL) quenching of an organic dye. The areal data resolution is at the diffraction limit of the CW Blu-ray (BR) laser employed, and the co-extrusion technique allows for small layer spacings, leading to a total bit density 1.2 Tb/cm3. We anticipate materials already demonstrated successful for 3D ODS will be adapted to this technique, as well as new systems developed, to take full advantage of this medium.

The introduction of gain into an optical medium is most easily accomplished by reversing the sign of the extinction coefficient. The theoretical expression for reflectance at a simple boundary between a dielectric, lossless incident medium and a medium with a finite extinction coefficient, however, takes no account of the sign of the extinction coefficient In such an arrangement, therefore, can the presence of gain possibly result in an enhanced reflectance? Opinions in the literature differ but tend to find enhancement beyond the critical angle and none below. This study examines both cases and shows that all results are in fact correct but they are not necessarily stable and it is their stability, or lack of it, that leads to the different results.

Bi-directional viewer just likes a lens of camera. Unlike conventional camera lens, the bi-directional viewer captures not only front view but also side view around the bi-directional viewer. The barrel of bi-directional viewer was designed to have cuts in the side to allow side light to come through, and we use two aspherical mirrors to receive and change the side light to converge on the main optical path. The front view and side view can be imaged simultaneously on an image sensor. Commercial aspherized achromatic lens and micro video lens were also used to keep the image quality and miniaturize the size of the bi-directional viewer respectively. We report on the development of bi-directional viewer, including optical design, optical simulation, optomechanics design, fabrication techniques, assembly procedure and performance testing. The MTF of the bi-directional viewer is also measured and discussed in this paper. We successfully design and realize a bi-directional viewer, which can perform 100 lp/mm spatial frequency image in detail above 20% contrast in the 7.6 mm front view area. And we keep the dimensions of this device within 35 mm in total length and Φ20 mm in diameter.

This paper presents the analysis of static structure and wavefront error (WFE) of a telescope experimental model’s primary mirror. The experimental telescope with 280mm diameter primary mirror had been assembled and aligned in 2011. The WFE result was not perfect. In order to find out the root cause of the WFE, the static structure analysis had been applied to the structure model of the telescope assembly. Some assumed effects which may cause deformation of the primary mirror had been proposed, such as gravity effect, iso-static mount (ISM) bonding effect, thermal expansion effect, etc. According to each assumed effect, we established a corresponding model and boundary setup. The numerical model was also analyzed by static structure analysis software and opto-mechanical analysis software to obtain numerical WFE and Zernike polynomials. The numerically synthetic optical system WFE was compared with measured system WFE of the telescope. According to the results of these deformation effects of the primary mirror, we could get the root cause of the system WFE. In the next generation of telescope, the opto-mechanical design and alignment process would be refined, and applied to the new optical system.

In this study, efficient polishing processes with inspection procedures for a large convex hyperbolic mirror of Cassegrain optical system are presented. The polishing process combines the techniques of conventional lapping and CNC polishing. We apply the conventional spherical lapping process to quickly remove the sub-surface damage (SSD) layer caused by grinding process and to get the accurate radius of best-fit sphere (BFS) of aspheric surface with fine surface texture simultaneously. Thus the removed material for aspherization process can be minimized and the polishing time for SSD removal can also be reduced substantially. The inspection procedure was carried out by using phase shift interferometer with CGH and stitching technique. To acquire the real surface form error of each sub aperture, the wavefront errors of the reference flat and CGH flat due to gravity effect of the vertical setup are calibrated in advance. Subsequently, we stitch 10 calibrated sub-aperture surface form errors to establish the whole irregularity of the mirror in 160 mm diameter for correction polishing. The final result of the In this study, efficient polishing processes with inspection procedures for a large convex hyperbolic mirror of Cassegrain optical system are presented. The polishing process combines the techniques of conventional lapping and CNC polishing. We apply the conventional spherical lapping process to quickly remove the sub-surface damage (SSD) layer caused by grinding process and to get the accurate radius of best-fit sphere (BFS) of aspheric surface with fine surface texture simultaneously. Thus the removed material for aspherization process can be minimized and the polishing time for SSD removal can also be reduced substantially. The inspection procedure was carried out by using phase shift interferometer with CGH and stitching technique. To acquire the real surface form error of each sub aperture, the wavefront errors of the reference flat and CGH flat due to gravity effect of the vertical setup are calibrated in advance. Subsequently, we stitch 10 calibrated sub-aperture surface form errors to establish the whole irregularity of the mirror in 160 mm diameter for correction polishing. The final result of the Fabrication of ф160 mm Convex Hyperbolic Mirror for Remote Sensing Instrument160 mm convex hyperbolic mirror is 0.15 μm PV and 17.9 nm RMS.160 mm convex hyperbolic mirror is 0.15 μm PV and 17.9 nm RMS.

We propose a novel super-resolution scanning microscopy technique employing higher-order propagationinvariant laser beams. The technique is capable of resolving objects with lateral dimensions smaller than that of the focal spot size defined by a propagating TEM00 (single mode) Gaussian beam. The field distributions at the object plane are produced by employing a spatial phase modulator. The acquired signals from the localized laser beam nodes are employed in image reconstruction, resulting in post-processed super-resolved images. The desired increase in spatial resolution is associated with an increase in the time required to spatially probe the region of interest covered by the propagating optical field. Our technique is based on a single propagating laser field, and is therefore significantly simpler to implement than techniques employing composite laser fields, such as STED (stimulated emission depletion) microscopy.

A new method for the misalignments calculation has been developed based in the analysis of the coefficients of the Zernike polynomial adjustment to the on-axis wavefront of the optical system. By means of a study of the system behavior in front of misalignments when they are small perturbations of position around the nominal value, it is shown that the Zernike coefficients behaviour can be aproximated with a polynomial. The coefficients of the Zernike polynomial are used to form a system of non-linear equations where the unknown variables are the misalignment values. This system of equations can be solved to find the misalignments values. The method has been validated by the simulation of a triplet where the second lens is misaligned. A series of misalignments of decentering and tilt have been applied and by simulation the wavefront have been obtained. Then the method has been used to calculate the misalignments from the wavefronts. Good results have been obtained for decentering and tilt separetely. With this process, the error of calculation for the tilt and the decentering has been obatined to be less than 20% for the simulated triplet system.

The semi-spherical meter uses a photo-detector mounted on a mobile rectangular arc, which by means of two stepper motors describes the semi-spherical trajectories required. For controlling motors and data acquisition, a Peripheral Interface Controller (PIC) is employed, which helps keeping the low cost of the overall system. One of the stepper motors is located on the lateral axis of the device; that displaces the sensor along a semi-circular trajectory of 170°, almost complete meridians. Another motor located at the base of the device enables 360° rotation of the illumination source under test. The precision is increased by the using of two angle sensors located on the opposite lateral axis and on the mobile base of the illumination source. Additionally, before the data obtained from the photo-detector arrive to the PIC, a stage of signal conditioning is used. This step allows us to increase not only the precision, but also the versatility of the meter to analyze illumination sources of different sizes and fluxes. The communication protocol between the data acquisition stage and the computer is USART. A graphical user interface (GUI) is employed on the base of the hyperterminal. The number of measurement points is determined by programming the two motors. The mechanical structure provides enough rigidity for supporting the accuracy required by the data acquisition circuitry based on a PIC. Measurement of illumination sources of different sizes is possible by using adjustable lengths of the mobile base and the ring.

Hinds Instruments has provided photoelastic modulators (PEMs) to the photonics industry for over 40 years. In the past Bob Wang, et al. from Hinds have made two presentations,^1,2 at SPIE meetings, Basic Optical Properties of the Photoelastic Modulator Part I: Useful Aperture and Acceptance Angle and Part II: Residual Birefringence in the Optical Element. This presentation, Part III in the series, addresses the characteristics of the PEM that vary with temperature, highlighting effects on frequency and signal drift due to retardation changes. In addition, Part III will introduce a new PEM with advanced thermal control (PEM-ATC™). Data is presented that shows the increased stability of the PEM frequency and retardation signal using this new device.

Zoom lens with variable focal length is well fit for researching objectives far and near. Design of zoom lens working at mid-wave infrared wavelength (7.7-10.3_m) and its view field 10 degrees is presented. Determination of the initial configuration of the variable and the compensate groups are discussed according to the mechanism compensate curves. The compensate group is determined with positive power. Its focal length changes during a large scope, which is from 300mm to 100mm. And the corresponding F number variables from 3.75 to 1.25. So the residual aberration needs to be carefully corrected. The optimized zoom lens is composed of four group elements, and its performance reaches diffraction limited at each focal position.

The control of the railway track relative to the fixed system of reference is a necessary condition to ensure the safety of railway traffic. This paper describes the optical-electronic system of railway track control relative to the fixed system of reference. The system consists of two cameras and special marks. The system is installed on the leveling machine and performs measurements during its motion. System marks are installed on the contact-line supports. This paper presents the test results. The system determines the distance to the mark with an accuracy of 1.5 mm in the range of 1.5–7 mm and the vertical bias with an accuracy of 1.5 mm in the range of 200 mm. This paper describes the algorithms of the system, and special attention is paid to sources of error in such systems.

For E-beam transmission and transforming we developed an electrostatic focusing device with extraordinary demagnification and abilities for 100% transmission of an electron beam with uniform distribution of current density. This experimental electrostatic focusing system consists of two sections; the first is field formation and second is field free - for measurement space¹. The purpose of this article is to present the experimental results from our electro-optical system. The measurement instrument used in the laboratory set up is an adjustable scanning system, which includes a faraday cup with a 14um diameter tungsten wire, for measuring different cross sections. The measurement of the crossover point is based on a combination of theoretical and experimental processes. The theoretical uses calculations from the “CPO”² program and the experimental measures different cross sections which are much larger than the diameter of the tungsten wire. Theoretically, from trajectory calculations, the crossover point is approximately 0.446μm. This estimation is obtained by drawing an isosceles triangle from the experimental results and comparing it to another isosceles triangle created from the theoretically calculated trajectories. Both triangles together have a geometrically proportional ratio and differ by about one percent or less. The design of the electrostatic focusing system is achieved utilizing the CGMR (Cone and Golden Mean Ratio) approach ^{1, 3 and 4}. This system is suitable for use in X-ray tubes5, e-beam lithography, SEM, high speed photonic technology, and also for any EOS.

The purpose of this research was to investigate the optical and structural properties of tungsten oxide (WO₃) thin films deposited with three different sputtering power supplies: direct current (DC), DC pulse and radio frequency (RF). These WO₃ thin films were deposited on ITO glass and silicon substrate with different gas ratios of oxygen and argon (O₂/Ar ratio). WO₃ thin film is the role of the electrochromic window was resulted from the advantages of large variation in optical density, high response efficiency, no toxicity and low cost. The experimental results showed that optical intensity increased with the increasing of O₂/Ar ratio and all films have the 950cm^-1 peak which the bonding of W⁺⁶=O in Raman spectra. Hence, the O₂/Ar ratio was changed from 0.4 to 0.8 to study the ability of coloring and bleaching for the three different power supplies. Anyways, the WO₃ thin films had the best electrochromic property at the O₂/Ar ratio of 0.7, 0.6 and 0.6 for DC, DC pulse, and RF, respectively. The transmittances could be over 75% for all films at as-deposited and the deposition rates were between 0.8 and 0.1 Ås^-1. Simultaneously, the transmittance variations (ΔT) were 51%, 57% and 53% for DC, DC pulse, and RF power sources at wavelength of 550 nm, respectively. The coloration ability of WO₃ thin film deposition with power supply of DC pulse was better than that of the DC and RF.