This PDF file contains the front matter associated with SPIE Proceedings Volume 7786, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Currently, the most popular instrument for chromaticity measurement consists of a power detector with several color filters of transmission spectra approaching to the color matching functions from the CIE 1931 standard observers. Unavoidably, there exist mismatches between the transmission spectrum of color filters and color matching functions. Therefore, the calibration process is obviously very important to the accuracy and the precision for the chromatic tri-stimulus values measurement in the colorimeters. In spite of several methods having been developed for the calibration procedures, the correction condition is only set to one certain illumination condition. Two most adapted standard illuminating conditions are the CIE standard illuminant D65 under correlated color temperature (CCT) 6504K, and the CIE standard illuminant A under CCT 2856K. However, in the general applications, the practical illuminating conditions for measurements are very difficult to be the same as the calibration one. In this work, the impulse response analysis has been applied for the error analysis. From the spectral mismatches of the color filters in colorimeters. A quantitative formula has thus been developed for the evaluation of the correction for the chromatic tri-stimulus values due the mismatch of the color filters under various CCT illumination condition. Based on this formula, the previously unknown deviation in the chromatic measurement under different CCT condition now can be further reduced down. In summary, the filter-type colorimeters with the calibration procedure according to our correction formula will perform much higher precision but still keep its simple and convenient use.

In this paper, we propose and demonstrate a novel design to make color mixing and projection of RGB LEDs. The optical elements include a high reflective light pipe, a volume scattering diffuser and a TIR lens. The system optical efficiency is around 46 % while the color is well mixing for the cases at the CCTs of 6500K, 4500K and 3000K.

We have designed and fabricated angle-selective filters to increase the luminous throughput of a blue light emitting diode (LED) and its associated color wheel. The emission direction was tailored to increase the light emission in the useful direction by using multilayer optical coating with alternating high and low refractive indices layers. The angle selective filters limit the luminance angle to less than an acceptance angle of 30 degrees for green and red on the phosphors color wheel. The filters increase the luminance efficiency by converging and recycling the light. The color performance of the phosphors color wheel was improved and gave an advantage of energy saving in the LED projector.

In the paper, we present a design of street light with use of a TIR lens and a specific diffuser of micro-lens array. In the illumination area of 39 m × 16.4 m, the power, output flux and the efficiency of the street light on the target area are about 160 W, 10530 lm and 85 %, respectively, and the uniformity reaches 1/1.64.

In this paper, we demonstrate a method to calculate the phosphor particle numbers and study the relationship among phosphor particle numbers, light output and correlated color temperature (CCT) of LEDs under remote package type and dispensing package type. We also discuss the influence of the thickness and concentration of phosphors on the performance of LEDs. We compare the various thicknesses and concentrations to check the resultant CCT and the output flux, where we can see that the lumen output is almost equal as the phosphor particle numbers is similar with the CCT at 6500±200 and 5000±100 K under the remote package type.

A new approach for 'ab initio' synthesis of thin lens structure of zoom lenses is reported. This is accomplished by an implementation of evolutionary programming, based on Genetic Algorithm, which explores the available configuration space formed by powers of individual components and inter-component separations. Normalization of the variables is carried out to get an insight on the optimum structures. The method has been successfully used to get thin lens structures of mechanically compensated, optically compensated, and linearly compensated zoom lens systems by suitable formulation of merit function of optimization. Investigations have been carried out on three component and four component zoom lens structures. Illustrative numerical results are presented.

In this paper GPU based data parallel technique is used to reduce calculating time in diffractive optics elements (DOE) design. By using compute unified device architecture (CUDA) framework, comparison of acceleration radio of some major methods using in DOE design, including Gerchberg Saxton algorithm for global optimization in conjunction with Rayleigh-Sommerfeld diffractive integrating transformation, genetic algorithm with a finite-difference time-domain method and simulated annealing algorithm, is made with demonstrational DOE-lens design, whose focal spot size is 0.5 μm, incident light wavelength is 650 nm, focal length is 3mm, DOE aperture size is 2mm.

Although several applications of machine vision and biomedical imaging ask for the close-up imaging of extended object fields, only few, mostly bulky solutions exist. We demonstrate the optical design and realization of an ultra-compact close-up imaging system with unity magnification. It uses a multi-aperture approach in order to shorten its total track length to less than 4 mm while achieving a large field of view. The system is made of a stack of several two-dimensional arrays of refractive microlenses. The potential of this setup lies in the combination of digital imaging with microoptical fabrication techniques leading to thin optical components which can be directly attached to an image sensor. Hence, these systems fit into tight spaces and they achieve a high resolution without scanning.

A lens design having constant working distance while having variable recording depth for micro holographic data storage system has been proposed. Variation of focal length is suppressed for the entire depth within 1% which enables focusing and tracking servoing without changing servo parameters.

Launch Vehicle Imaging Telescopes (LVIT) are expensive, high quality devices intended for improving the safety of vehicle personnel, ground support, civilians, and physical assets during launch activities. If allowed to degrade from the combination of wear, environmental factors, and ineffective or inadequate maintenance, these devices lose their ability to provide adequate quality imagery to analysts to prevent catastrophic events such as the NASA Space Shuttle, Challenger, accident in 1986 and the Columbia disaster of 2003. A software tool incorporating aberrations and diffraction that was developed for maintenance evaluation and modeling of telescope imagery is presented. This tool provides MTF-based image quality metric outputs which are correlated to ascent imagery analysts' perception of image quality, allowing a prediction of usefulness of imagery which would be produced by a telescope under different simulated conditions.

The success of many advanced technologies increasingly depends on the precision of the optical lenses used. Therefore the demand for high precision optical elements in more common devices and instruments is increasing as well. Concurrently the need to make devices smaller and lighter weight is also driving the demand for precision optical elements. Therefore, the use of aspherical glass lenses is growing tremendously and has become the standard for many applications. So far most methods for manufacturing aspherical glass surfaces use grinding and polishing. Very sophisticated methods such as Ion Beam Figuring have not been used for common precision optics. The reasons for this might be perceptions of high costs, doubt about the ablation rate and limited knowledge about the technique within the optical industry. Now Asphericon has set up its first ion beam correction system for precision aspherical optics (asphericon ION-Finish). This presentation will show how the ion beam technology has matured and become affordable enough for common precision applications. In some examples we will show how ion beam systems are used to correct aspheres to precisions of better than lambda/60 rms (10nm). Together with a flexible measurement technique, the manufacturing of aspherical glass lenses becomes very fast and cost-efficient. Furthermore, advantages and disadvantages will be discussed. In connection with that the required quality of the pre-polishing will be addressed too. Finally it will be shown how fast the correction process can be and how flexibly the size of the tool can be changed.

Photonic jets can be produced by the illumination of a micrometer dielectric particle by an optical plane wave, and are characterized by a narrow elongated focal volume. Bessel beams have been widely studied in recent decades and are commonly referred to as being "diffractionless" over long distances. The Bessel beam aspects of photonic jets are investigated in this manuscript. In particular, we show that photonic jets take their properties from Bessel propagative beams, but more complex phenomena are involved.

Non-mechanical variable lenses are important for creating compact imaging devices. Various methods employing dielectrically actuated lenses, membrane lenses, and/or liquid crystal lenses were previously proposed^1-4. Here we present tunable-focus flat liquid crystal diffractive lenses (LCDL) employing binary Fresnel zone electrodes fabricated on Indium-Tin-Oxide using conventional micro-photolithography. The phase levels can be adjusted by varying the effective refractive index of a nematic liquid crystal sandwiched between the electrodes and a reference substrate. Using a proper voltage distribution across various electrodes the focal length can be changed. Electrodes are shunted such that the correct phase retardation step sequence is achieved. If the number of 2π zone boundaries is increased by a factor of m the focal length is changed from f to f/m based on the digitized Fresnel zone equation: f = r_m ²/2mλ, where r_m is m^th zone radius, and λ is the wavelength. The lenses operate at very low voltage levels (±2.5V ac input), exhibit fast switching times (20-150 ms), can have large apertures (>10 mm), and small form factor, and are robust and insensitive to vibrations, gravity, and capillary effects that limit membrane and dielectrically actuated lenses. Several tests were performed on the LCDL including diffraction efficiency measurement, switching dynamics, and hybrid imaging with a refractive lens. Negative focal lengths are achieved by adjusting the voltages across electrodes. Using these lenses in combination, magnification can be changed and zoom lenses can be formed. The promising results make LCDL a good candidate for non-mechanical auto-focus and zoom lenses.

There is an enormous range of possible color distributions that may be created with a light cone when the primary source is an array of multicolor light-emitting diodes (LEDs). If one looks through a lightpipe toward an LED array, multiple images of the color LEDs can be observed as in a kaleidoscope. A tapered lightpipe behaves as a three-dimensional kaleidoscope, and then, by changing the position and orientation of the red-green-blue LEDs can produce a plenty of amazing illumination patterns. We analytically calculate this color spatial distribution of the illumination pattern produced by a tapered lightpipe. Moreover, we simulate these color illumination patterns, and analyze their structure and symmetry.

Gold-coated mirrors are widely used in infrared optics for industrial, space, and military applications. These mirrors are often made of aluminum or beryllium substrates with polished nickel plating. Gold is deposited on the nickel layer by either electroplating or vacuum deposition processes. Atmospheric corrosion of gold-coated electrical connectors and contacts was a well-known problem in the electronic industry and studied extensively. However, there is limited literature data that correlates atmospheric corrosion to the optical properties of gold mirror coatings. In this paper, the atmospheric corrosion of different electroplated gold mirror coatings were investigated with an accelerated mixed flowing gas (MFG) test for up to 50 days. The MFG test utilizes a combination of low-level air pollutants, humidity, and temperatures to achieve a simulated indoor environment. Depending on the gold coating thickness, pore corrosion started to appear on samples after about 10 days of the MFG exposure. The corrosion behavior of the gold mirror coatings demonstrated the porous nature of the electroplated gold coatings as well as the variation of porosity to the coating thickness. The changes of optical properties of the gold mirrors were correlated to the morphology of corrosion features on the mirror surface.

In order to use infrared windows in the electro-optical systems, which are integrated to the air platforms, its strength and durability should be high enough for harsh environmental conditions. One of the most challenging environmental conditions is the rain erosion. An infrared substrate may not continue its necessary functions at high velocity flight under rain. Special coating techniques should be used for the infrared transparent substrate to increase its durability. In this study, development of the hard carbon coating, whose substrate material is Germanium, will be discussed. Finite element analysis of the substrate material will be compared with the rain erosion test data. Test results for the developed coating will also be presented to show the improvement on durability performance.

Previous publications for the JWST-FGS-TFI instrument described the design and fabrication of mirror coatings for scanning Fabry-Perot etalons. Since that time, we have extended the fabrication process using ellipsometry analysis over the full operational bandwidth from 1.0 to 5.0 microns for both mirror and anti-reflection coatings. This paper will present single and multiple layer ellipsometry analysis of the a-Si/SiO₂ optical properties. Analysis improvement came from a-Si/SiO₂ interface consideration and simultaneous use of ellipsometric data from Woollam V-VASE and IRVASE instruments. Simulations of reflectance and transmittance based on the ellipsometric analysis results will also be compared to spectrophotometric measurements for witness pieces.

Normally metallic films are required for solar energy and display related coatings. To increase the absorbing efficiency or contrast, it is necessary to apply an antireflection coating (ARC) on the metal substrate. However, the design of a metal substrate is very different from the design of a dielectric substrate, since the optical constant of metallic thin film is very dependent on its thickness and microstructure. In this study, we design and fabricate ARCs on Al substrates using SiO₂ and Nb₂O₅ as the dielectric materials and Nb for the metal films. The ARC successfully deposited on the Al substrate had the following structure: air/SiO₂/Nb₂O₅/Metal/Nb₂O₅/Al. The measured average reflectance of the ARC is less than 1% in the visible region. We found that it is better to use a highly refractive material than a low refractive material. The thickness of the metallic film can be thicker with the result that it is easier to control and has a lesser total thickness. The total thickness of the ARC is less than 200 nm. We successfully fabricated a solar absorber and OLED device with the ARC structure were successfully fabricated.

This paper discusses a method to characterize feathering and determine feathering quality. The characterization is based upon the change of the color coordinate across the transition region. "Feathering" of an optical coating is the gradual taper, without any discernible boundary, from a coated to uncoated region. There can be various reasons why a thin film optical coating may not be applied to the entire surface of a see-through article. Feathering is necessary when the viewer, looking through a transmissive element, is focused on the far-field and would be distracted by a coating boundary which redirects focus to the near field. Done incorrectly, feathering may produce visible artifacts which are ineffective and objectionable to the user. Examples are provided.

Transparent conducting Fluorine-doped tin oxide (FTO) thin films were deposited on glass substrates by pulsed DC magnetron sputtering from cost saving metal targets. We observed lower resistivity and higher average transmittance in the visible range after the application of various post heating treatments. The electrical and optical properties of FTO films were investigated. When the annealing temperature is 400°C in air, the average transmittance is 79.79% with the lowest resistivity of 1.38×10^-3 Ω-cm, carrier density of 2.27×10²⁰ cm^-3 and mobility of 20 cm²/ V-s. When the annealing temperature is 400°Cin a H₂ 5%+N₂ 95% atmosphere, the average transmittance is 79.75 % with the lowest resistivity of 1.26×10^-3 Ω-cm, carrier density of 2.17×10²⁰ cm^-3 and mobility of 22.8 cm²/ V-s. When the annealing temperature is 350 °C in vacuum, the average transmittance is 80.48% with the lowest resistivity of 1.23×10^-3 Ω-cm, carrier density of 4.40×10²⁰ cm^-3 and mobility of 11.6 cm²/ V-s.

Nb doped TiO₂ (TNO) is a promising transparent conducting oxide suitable for many applications such as in solar cells, OLEDs, LEDs, FPDs, touch panels, etc. TNO thin film was deposited on an unheated glass substrate by pulsed direct current (DC) magnetron co-sputtering. After annealing in a vacuum (<9×10^-6 Torr) at 370° for 10 minutes, the film crystallized into a polycrystalline anatase TiO₂ structure, the resistivity decreased to 4.5×10^-4 Ω-cm and the average transmittance increased to above 70% in the visible light region. The influence of annealing on the TNO amorphous-to-anatase phase transition, decrease in the resistivity and increase in the average transmittance will be discussed.

Thin films of tungsten oxide (WO3) were deposited on GZO-coated B270 glass substrates and thin films of Ta₂O₅ were deposited on B270 glass substrates by electron beam gun evaporation at high vacuum pressure of 3×10^-5 Torr and varied oxygen pressures ranging from 1.0×10^-4 to 6.0×10^-4 Torr. The optical properties of the electro-chromic (EC) film were measured by a spectrophotometer. The optical modulation (ΔT) of the tungsten oxide thin film deposited at an oxygen pressure of 1.0×10^-4 Torr was found to be ΔT = 67.46% at λ=550nm. The optimum optical properties for deposition of Ta₂O₅ were attained at an oxygen pressure of 4x10^-4 Torr. Gallium doped zinc oxide (GZO) was used as a conductive layer instead of ITO. A five layer EC device (Glass/GZO/WO₃/Ta₂O₅/NiO/Al) has been design and fabricated.

In order to determine the vibration effects on performance in optical system, a simple vibratory model is proposed. The model suggested is compared with FE model. Both models are validated by modal tests for an existing simple optical system. The material properties of adhesive, which play an imported role in the vibratory model of an optical system, are found experimentally by using a simple test setup. The model suggested is used to investigate the dynamic behavior of the optical system under random vibration load conditions. It is concluded in this study that the analytical model suggested can successfully be used in preliminary design stage of simple optical systems when optical housing and lens behave rigidly in the frequency range of interest.

Improving of the autocollimating systems characteristics is a line of optical engineering development. It is associated with study of initial errors and ways of their reduction. Study is devoted to the influence of tetrahedral reflectors properties (errors of dihedral angles) on the characteristics (accuracy et al) of autocollimating and autoreflection opticalelectronic systems for positioning control. The MATLAB mathematical model of tetrahedral reflector was developed for these purposes; results of simulation were compared with Zemax simulation. It is important to notice that the process of image formation is quite complex, it explains by superposition of six reflected and deflected beams. Because of the dihedral angle errors six compound images separate or overlap; that causes the redistribution of energy and image becomes complicated for processing. The aim is to study the influence of reflector properties on position of the image energy center, because it defines the measurement error. The influence of the tetrahedral reflector properties on system's characteristics is shown by example of shift control system based on autoreflection scheme.

Panoramic imaging is of growing importance in many applications around the world spurred by the development of digital imaging. Panoramic lens characteristics are unique and their careful characterization can be a challenge. For example, the price to pay for a large field of view in this type of lens is high distortion in the image. For vision applications like security or inspection, a precise knowledge of the distortion introduced by panoramic lenses is essential to produce natural unwrapped views to the operator. Of special concern is the image quality which must be uniformed over the entire field of view because all directions are equally important. In addition, two hemispheric images can also be stitched together to create a complete spherical image. For these reasons, we have developed a dedicated setup to study the distortion and the image quality produced by panoramic lenses. The test setup is made of a 75-cm radius cylindrical structure with targets placed on it. Using referenced equally-spaced targets, we obtained the radial image mapping curves for various azymuthal angles, allowing us to calculate the full-field resolution map. Also, transition targets were used to find field-dependent spatial frequency where the MTF is 50%. We tested four different panoramic lenses, two panomorph lenses and two fisheyes. For each lens, we discussed the experimental resolution and MTF curves and compared some of those results to theoretical design data.

The paper presents the mathematical technique for calculation of the diffraction depth of focus of an optical system of a widefield microscope. The proposed technique applies the Rayleigh criterion based on evaluation of the wave aberration appeared due to defocus in a high aperture optical system. The maximal value of a linear approximation of the defocus wave aberration is used to define the depth of focus. It is proven that in optical systems with numerical aperture higher than 0.5 have the diffraction depth of focus 25 - 40 % smaller than the widely known formula defines. This fact is important for implementation of autofocus and digital focus extension algorithms. The non-sophisticated formula for calculation of the depth of focus is proposed. The results of experimental measurements of the depth of focus are presented and discussed.

The Fine Guidance Sensor (FGS) is part of the science instrumentation for the James Webb Space Telescope (JWST). The FGS is required to operate at 37 K and provide the data needed to facilitate fine pointing and attitude stabilization necessary to meet the requirements of the mission's science and engineering operations. We describe here the selection of the proper optical design form to meet requirements and its relative merits. The FGS has progressed with the successful completion of several key design reviews. The optical design of the current stage will be discussed here in detail.

Super mirror is a high reflectance mirror with very low absorption and scattering losses. We carefully measured the surface roughness of Zerodur substrate using phase shift interferometer and atomic force microscope, and compared it with the scattering of the mirror. The absorption of the mirror was measured by cavity ring-down method, and its results were correlated to the thin film structure. To avoid the UV degradation which comes from the He-Ne plasma, we carefully select the mirror fabrication material, and design the high reflectance mirror. Finally, mirror was fabricated by ion beam sputtering method and its optical properties were measured.

In ultra-precision (distortion < 0.5 %) vision inspection system, the accuracy of measurement depends on sharpness and distortion of image. The telecentric lens provides distortion-free and constant magnification (within depth of field) image, so it has become an indispensable key module in the amount of visual measuring system. The article presents a design and development of telecentric lens module for the wide range of vision inspection system (field-of-view > 100 mm). Based on the concept of equivalent design in optical tolerances, the lens module can be designed readily into a telecentric system, which consists of five spherical lenses and a glass molded aspheric lens. In order to correct image distortion, an aspheric lens would be added to the telecentric system. The experiment shows that the distortion can be reduced from 1.5 % to 0.34 % and the depth of field (DOF) is also improved up to 28.3 mm.

Problems of improving efficiency and quality of diamond-abrasive finishing of optical materials by tools with bounded polishing powders, including diamond powder, by means of the improvement of the machining technology and application of new tools with functionally oriented designs and characteristics of working layer are considered. A model has been proposed of the slime particle formation and directional removal as well as of the generation of a high-quality surface in diamond-abrasive finishing of optical materials taking into account the peculiarities of the mass transfer in the contact zone and statistic character of the distribution of slime particles by size. The dependences of the particle number on the diffusion angle and coordinate of the contact have been derived in the studies of the dynamics of collision and diffusion of slime particles. The coordinate dependence of the flat surface roughness of glass K8 optics in fine diamond grinding has been described. Interaction and dispersion of deterioration particles in a contact zone of the tool and a processed sample in the course of polishing is described and the dispersion structure of deterioration particles of the tool on slime particles and on deterioration particles is explained oscillatory. It is shown, that differential dispersion section of deterioration particles on slime particles no less than on deterioration particles as much as possible at corners of dispersion close to 0 and 180° on the central sites of a contact zone. Coordinate dependence of full dispersion section of deterioration particles of the tool and dependence of microprofile height of the processed surface on circular zones radius are calculated. Conformity of experimental and theoretical microroughness profiles of a polished surface on a quartz sample is shown.

In this contribution we present a technology for deposition of interference coatings for optical components designed to operate as active media in power pulsed lasers. The aim of the technology is to prepare crystals for lasers for the HiPER project (High Power laser Energy Research) which should demonstrate the feasibility of laser driven fusion as a future energy source. Diode pumped solid state lasers (DPSSL) are the most likely option for fusion ignition. The choice of material for the lasers active medium is critical. Some of the most important properties include the ability to be antireflection coated to reduce the energy losses and increase the overall efficiency. This contribution deals with some of the materials considered to be candidates for slabs serving as the active medium of the DPSSLs. We tested Yb:YAG, Yb:CaF₂ samples. As large amounts of heat need to be dissipated during laser operation, cryogenic cooling is necessary. Appropriate coating materials and techniques need to be chosen. Therefore differences between available coating techniques are investigated in terms of adhesion, enduring of stress resulting from temperature shocks, etc. Coated samples were placed into cryogenic environment in order to simulate conditions similar to those in real life operation. Optical microscopy was used for coating investigation after the conducted experiments.

Recently in the micro-optical engineering area has been a grown in use of tunable liquid lenses because this lenses us allow versatility in the focusing range, also an easy handling and implementation. In the literature, many tunable lens models have been reported, but most of this work has been on describing the optical quality of the images, the opto-mechanical analysis is neglected. In this paper, an analysis of opto-mechanical of a tunable liquid lens is presented, for this; we show a finite element simulation of mechanical behavior and estimate how this influences in the optical performance of the lens. The liquid lens is composed of two elastic transparent membranes and of a cylindrical metallic mount.

In this research, a new module of skin treatment has been proposed. The 40 pieces of red and 36 pieces of yellow LEDs are utilized to be the light sources in treatment the cracks and corrosions on skin, and the 4 pieces of white light LEDs are applied in lighting on skin. In addition, the image of skin could be obtained by a CCD webcam, and the skin inspection will be determined by number of pores in images. Finally, the good experimental results have been obtained in human body.

Achromatic doublet theory is recast for the 1-2.5μm short-wavelength infrared band, suggesting the desirability of combining barium fluoride with specific high index optical glasses having large differences in primary SWIR dispersion and small differences in partial SWIR dispersion. Candidate combinations of materials are screened empirically using the performance of optimized f/3 airspaced achromatic doublets employing barium fluoride as the positive element. Polychromatic RMS geometric image spot sizes appear to increase quadratically with difference in partial SWIR dispersion between barium fluoride and the complementary glasses. Examples of complex (fast, wide field) systems demonstrate the utility of the most promising combinations.

The use of IR optical substrates and thin-films is an integral part of optical system construction for remote sensing instrumentation. From telescopes to multi-spectral imagers, entire optical systems can be built with a relatively small set of materials. The temperature dependence of the optical, mechanical and electronic properties of bulk infrared (IR) materials has been well characterized in the literature [1-5]. Manufacturer and research reports provide some representation of the impact of temperature excursions on the index of refraction (dn/dT), and the absorption profile (dk/dT) of bulk crystalline germanium (Ge) and synthetic crystalline zinc sulphide (ZnS). The availability of empirical data for thin-films, however, is much more limited. These optical constants for as-deposited amorphous thin-films of Ge and ZnS are investigated. Models for the temperature dependent refractive index have been developed using transmittance and reflectance data over the wavelength region between 2.0-20.0 μm. The spectra of manufactured filters are characterized at ambient and cryogenic temperatures (300K-50K) in order to validate the models developed.