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Ptychography is a scanning coherent diffraction imaging technique that provides high-resolution imaging and complete spatial information of the complex probe and object transmission function. The wavefront error caused by aberrated optics has previously been recovered using ptychography when a highly coherent source is used, but has not been demonstrated with partial coherence due to the multi-modal probe required. Here, we demonstrate that partial coherence can be accounted for in ptychographic reconstructions using the multi-modal approach and assuming that decoherence arises from either the probe or the object. This equivalence recovers coherent (or single state) reconstructions of both the probe and the object even in the presence of partial coherence. We demonstrate this experimentally by using hard x-ray ptychography with a partially coherent source to image a Siemens star test object and to also recover the wavefront error from an aberrated beryllium compound refractive lens. The source properties and resolving capabilities are analyzed, and the wavefront error results are compared with another at-wavelength metrology technique. Our work demonstrates the capability of ptychography to provide high-resolution imaging and optics characterization even in the presence of partial coherence.

This study aimed to develop and evaluate a blind-deconvolution framework using the alternating direction method of multipliers (ADMMs) incorporated with weighted L1-norm regularization for light microscopy (LM) images. A presimulation study was performed using the Siemens star phantom prior to conducting the actual experiments. Subsequently, the proposed algorithm and a total generalized variation-based (TGV-based) method were applied to cross-sectional images of a mouse molar captured at 40× and 400× on-microscope magnifications and the results compared, and the resulting images were compared. Both simulation and experimental results confirmed that the proposed deblurring algorithm effectively restored the LM images, as evidenced by the quantitative evaluation metrics. In conclusion, this study demonstrated that the proposed deblurring algorithm can efficiently improve the quality of LM images.

The article presents the determination of the topographic spatial resolution of an optical point sensor. It is quantified by the lateral period limit DLIM measured on a type ASG material measure, also called (topographic) Siemens star, with a confocal sensor following both a radial measurement and evaluation, as proposed by ISO 25178-70, and the measurement and subsequent evaluation of two line scans, proposed by the NPL Good Practice Guide. As will be shown, for the latter, an only slightly misidentified target centre of the Siemens star leads to quite significant errors of the determined DLIM. Remarkably, a misidentified target centre does not necessarily result in an overestimation of DLIM, but lower values might also be obtained. Therefore, a modified Good Practice Guide is proposed to determine DLIM more accurately, as it includes a thorough determination of the centre of the Siemens star as well. While the measurement and evaluation effort is increased slightly compared to the NPL Good Practice Guide, it is still much faster than a complete radial measurement and evaluation.

X-ray ptychography, a technique based on scanning and processing of coherent diffraction patterns, is a non-destructive imaging technique with a high spatial resolution far beyond the focused beam size. Earlier demonstrations of hard X-ray ptychography at Taiwan Photon Source (TPS) using an in-house program successfully recorded the ptychographic diffraction patterns from a gold-made Siemens star as a test sample and retrieved the finest inner features of 25 nm. Ptychography was performed at two beamlines with different focusing optics: a pair of Kirkpatrick–Baez mirrors and a pair of nested Montel mirrors, for which the beam sizes on the focal planes were 3 µm and 200 nm and the photon energies were from 5.1 keV to 9 keV. The retrieved spatial resolutions are 20 nm to 11 nm determined by the 10–90% line-cut method and half-bit threshold of Fourier shell correlation. This article describes the experimental conditions and compensation methods, including position correction, mixture state-of-probe, and probe extension methods, of the aforementioned experiments. The discussions will highlight the criteria of ptychographic experiments at TPS as well as the opportunity to characterize beamlines by measuring factors such as the drift or instability of beams or stages and the coherence of beams. Besides, probe functions, the full complex fields illuminated on samples, can be recovered simultaneously using ptychography. Theoretically, the wavefield at any arbitrary position can be estimated from one recovered probe function undergoing wave-propagating. The verification of probe-propagating has been carried out by comparing the probe functions obtained by ptychography and undergoing wave-propagating located at 0, 500 and 1000 µm relative to the focal plane.

X-ray ptychography has revolutionised nanoscale phase contrast imaging at large-scale synchrotron sources in recent years. We present here the first successful demonstration of the technique in a small-scale laboratory setting. We conducted an experiment with a liquid metal-jet X-ray source and a single photon-counting detector with a high spectral resolution. The experiment used a spot size of 5 microns to produce a ptychographic phase image of a Siemens star test pattern with a sub-micron spatial resolution. The result and methodology presented show how high-resolution phase contrast imaging can now be performed at small-scale laboratory sources worldwide., Comment: 14 pages, 4 figures

A markerless projection drift alignment approach for X-ray nanotomography is presented. Drifts in projection from different angles are aligned by applying offsets calculated between successive images after acquisition time division, taking the advantage of the fact that the shorter the time, the less the drift. Involving neither iteration nor parameter selection, it can combine a number of existing image registration techniques and could be adopted for other tomographic imaging techniques. The application of this algorithm has been demonstrated in a laboratory X-ray nanotomography system using single photon detection, in which a standard Siemens star resolution target is initially captured for 2D evaluation and a bamboo stick is used for 3D imaging, leading to sharper image without blur and a much higher resolution.

This study proposes and demonstrates a compact synthetic aperture digital holographic microscope (SA-DHM) with mechanical movement-free beam scanning and optimized active aberration compensation. The SA-DHM system is equipped with a phase-only liquid crystal on silicon (LCoS) device as an active optical element to achieve a compact mechanical movement-free beam steering architecture with aberration correction. A rigorous optimization is conducted to modulate the LCoS device using the designed computer-generated holograms (CGH) to generate a high-quality point spread functions (PSF) for a wide range of scanning angles. An accurate aberration correction is studied with and without oil immersed conditions on microscope objective lens. The performance of the proposed method is analyzed with Siemens star target and the results show its potential capability to achieve isotropic resolution enhancement.

Today's consumers are looking for powerful, multifunctional electronic devices with unprecedented performance and speed, yet small, thin and low cost. This creates complex technology and manufacturing challenges for semiconductor companies as they look for new ways to achieve greater performance and functionality in a small, thin, low cost device. JCET is an industry leader in Wafer Level Packaging (WLP) technology, providing a comprehensive portfolio of WLP solutions including Fan-in Wafer Level Packaging (FIWLP), Fan-out Wafer Level Packaging (FOWLP) and Integrated Passive Devices (IPD This paper shares data and results from our labs and those of our technology partners which come from two recent tube technology advances, both show great potential for providing solutions to the issues of imaging small features quickly, faced in the higher end semiconductor manufacturing industry. Metal Jet Technology, in metal jet anode microfocus xray tubes the traditional solid metal anode is replaced with a jet of liquid metal, which acts as the electron-beam target, The metal jet supports higher electron-beam power and can therefore generate higher X-ray flux. The major benefit of the increased power density level for the metal-jet X-ray tube is the possibility to operate with a smaller focal spot, say 5 ?m, to increase image resolution and at the same time acquire the image faster, since the power is 10x higher for same spot size. Which means that a 5μm spot on a Metal Jet can tolerate approximately 5x higher power compared to a 10μm spot on a tube with a traditional solid filament This technology delivers one of the smallest and most intensive X-ray beams of any Xray source to meet the ever-increasing technology demands, including wafer level package inspection. Nano Tube Technology This enables industry-leading resolution in geometric magnification, the Nano tube is based on advanced electron optics and the latest tungsten-diamond transmission target technology. Automatic e-beam focusing, and astigmatism correction ensures that the smallest possible, truly round spot is achieved. The Nano tube also has the unique feature of internally measuring and reporting the current spot size. In addition, advanced cooling and thermal design results in extreme stability over time. This enables an unprecedented true resolution of 150 nm lines and spaces. The true round spot of the tube is demonstrated by the highly symmetric images of a ‘Siemens star’ resolution target, the innermost features are 150 nm

We applied a simple method to estimate the Minimum Resolvable Temperature Difference (MRTD) of an LWIR and an MWIR camera. A so-called Siemens star, in our case a thin, black aluminum plate framing a circle that is missing (cut out) every other spoke, is mounted in front of a black body whose temperature is relatively close to room temperature. From short recordings of the black body and Siemens star both the Noise Equivalent Temperature Difference (NETD) and the Modulation Transfer Function (MTF) are extracted and a simple estimate of MRTD = NETD/MTF is obtained. The imaged Siemens star almost completely covers the focal plane array; hence, an MRTD curve for the whole array is obtained. We investigated the effect of Non-Uniformity Correction (NUC) and Bad-Pixel Removal (BPX), two often applied pre-processing techniques, on the MRTD estimate. We find that (1) BPX has only limited effect on the result; (2) NUC is required to obtain a good MTF; and (3) NUC is not a prerequisite to obtain a good NETD estimate, but this is contingent on having a proper segmentation tool or template available. Without a segmentation algorithm, NUC together with simple intensity thresholding provides a sufficiently good segmentation and accordingly a good estimate of NETD.

Digital airborne camera systems and their high geometric resolution demand for new algorithms and procedures of image data analysis and interpretation. Parameters describing image quality are necessary for various fields of application (e.g. sensor and mission design, sensor comparison, algorithm development, in-orbit-behaviour of instruments). The effective sensor resolution is one important parameter which comprehensively estimates the optical quality of a given imaging sensor-lens combination. Although determination of resolving power is a well-studied field of research, there are still some scientific questions to be answered when it comes to a standardized (eventually absolute) determination. This is also research object of a committee of the “German Institute for Standardization” and the given contribution outlines the current state of investigation concerning effective resolving power for airborne camera systems. Therefore an approach using signal processing techniques to calculate the effective image resolution will be described. The open scientific issues will be introduced, explained and answered to some extend.

Digital Coplanar Translational Laminography (CTL) is a radiographic imaging technique that permits the visualization of structural details and discontinuities in the object of interest after 3D reconstruction from multiple projections. This technique becomes quite competitive regarding to computed tomography in situations of arrangements in which no complete rotation of the X-ray source - detector system around the object of interest is accessible or in cases where the part to be inspected has a high geometric asymmetry. The literature does not show many studies about image quality for different laminographic reconstructions and scan geometries. Different methodologies for measuring the Modulation Transfer Function (MTF) as a key image quality parameter for the aforementioned technique are applied. The MTF was measured using different approaches, pre-sampled MTF or sampled MTF, both based on the Fourier Transform-Magnitude Spectrum or the square wave MTF using line pattern gauges. A sample known as Siemens Star with a converging line pattern was used to measure the circular square wave MTF. This circular MTF provides information on the direction dependent contrast transfer related to the measurement conditions, the reconstruction algorithms and the translational scan direction. For this purpose, several MTF measurements were performed in multiple angular directions. Beyond it, reconstructions were performed using different algorithms (Filtered Shifted Average) and an iterative one (MART – Multiplicative Algebraic Reconstruction Technique). Image quality analysis were done for both reconstruction methods. MART showed an image quality improvement for challenging conditions for laminographic arrangements, such as for a low number of projections (down to 25 for this study, considered as limited view, limited angle reconstruction). Additionally, a Gadolinium gauge with parallel line patterns within a range from 10 μm to 1000 μm was used to compare the square wave MTF with the sine MTFs, measured by the different techniques mentioned above. The results show that the MTF techniques presented are equivalent in this study. The results obtained for this Gadolinium plate showed a good agreement between MTF10% and SRbimage measurements. The methodology presented here is used for the characterization of the frequency dependent spatial resolution of measurements obtained from different laminographic reconstruction techniques and scan geometries. Finally, from the acquisitions and reconstructions obtained with the Siemens Star, cross laminographic images were calculated in order to improve the direction dependent sensitivity. The results showed a better detectability for cross laminographic images in comparison to unidirectional coplanar translational laminographic images covering dead zones.

By virtue of its versatile recording geometries, ptychography is a promising full-field lensless phase imaging approach in the prosperous research area of terahertz imaging. In this paper, we propose an extrapolation extended ptychographical iterative engine, named as the EE-PIE reconstruction algorithm, to increase the lateral resolution of terahertz ptychography. A divergent spherical beam is applied to illuminate the object, while diffraction patterns are recorded in the Fresnel region. The signal-to-noise ratio of the diffraction patterns is enhanced under divergent probe illumination, while the size of the diffraction patterns is numerically enlarged by the proposed algorithm. Both the reconstruction quality and the resolution are enhanced without adding to the complexity of the setup or increasing the data acquisition time. The proposed method is experimentally demonstrated using a cluster of phylloclades, a patterned polypropylene plate and a Siemens star target. Compared with the planar illumination, the resolution of the divergent spherical illumination is improved by 2.14 times. On this basis, the extrapolation algorithm further improves the experimental resolution by 1.26 times.

The characteristics of the X-ray focal spot strongly influence XCT image sharpness and structural resolution. However, current international standards only yield a limited characterization of the focal spot as two perpendicular sizes. Therefore, this paper presents a method for full characterization of the focal spot in terms of both 2D shape and intensity distribution, by applying the inverse Radon transform on a radiograph of a Siemens star. The method is validated through simulations and applied experimentally to two XCT sources. Subsequently, an investigation on how the X-ray tube settings influence focal spot size, shape, intensity and stability is presented.

Ptychography has been developed and routinely employed as an at-wavelength metrology method on a low coherence dipole magnet beamline., Ptychography is a scanning coherent diffraction imaging technique which provides high resolution imaging and complete spatial information of the complex electric field probe and sample transmission function. Its ability to accurately determine the illumination probe has led to its use at modern synchrotrons and free-electron lasers as a wavefront-sensing technique for optics alignment, monitoring and correction. Recent developments in the ptychography reconstruction process now incorporate a modal decomposition of the illuminating probe and relax the restriction of using sources with high spatial coherence. In this article a practical implementation of hard X-ray ptychography from a partially coherent X-ray source with a large number of modes is demonstrated experimentally. A strongly diffracting Siemens star test sample is imaged using the focused beam produced by either a Fresnel zone plate or beryllium compound refractive lens. The recovered probe from each optic is back propagated in order to plot the beam caustic and determine the precise focal size and position. The power distribution of the reconstructed probe modes also allows the quantification of the beams coherence and is compared with the values predicted by a Gaussian–Schell model and the optics exit intensity.

Powder diffraction 35, 1-4 (2020). doi:10.1017/S0885715620000536, A provisional setup for X-ray microprobe experiments at 35 keV is described. It is based on compoundrefractive lenses (CRLs) for nanofocusing and a Vortex silicon drift detector with 2 mm sensorthickness for increased sensitivity at high energies. The Microprobe experiment (PETRA III) generallyuses Kirkpatrick-Baez mirrors for submicrometer focusing in the energy range of 5–21 keV.However, various types of scanning X-ray microscopy experiments require higher excitation energies.The CRL optics were characterized by X-ray ptychography and X-ray fluorescence (XRF) knife edgescans on a siemens star pattern and showed beam sizes down to 110 nm. The performance of the newsetup for microscopic X-ray diffraction (XRD)–XRF scanning X-ray microscopy measurements at35 keV is demonstrated on a cross-section of a painting fragment., Published by Cambridge Univ. Press, Cambridge

Effective image resolution is an important image quality factor for remote sensing sensors and significantly affects photogrammetric processing tool chains. Tie points, mandatory for forming the block geometry, fully rely on feature points (i.e. SIFT, SURF) and quality of these points however is significantly correlated to image resolution. Spatial resolution can be determined in different ways. Utilizing bar test charts (e.g. USAF51), slanted edges (ISO 12233) and Siemens-Stars are widely accepted techniques. The paper describes these approaches and compares all in one joint experiment. Moreover, Slanted-Edge and Siemens-Star method is evaluated using (close to) ideal images convolved with known parameters. It will be shown that both techniques deliver conclusive and expected results.

Spatial resolution of full-field X-ray microscopes based on total-reflection mirrors was limited by grazing-incidence angle of the mirrors. At practical conditions, achievable spatial resolution is approximately 30 nm. To overcome the limitation, multilayer advanced Kirkpatrick-Baez mirrors and full-field X-ray microscopes with this objective mirrors have been developed in Osaka University and RIGAKU Corp. One of the remarkable points in this design is an achievable spatial resolution of less than 20 nm owing to large grazing-incidence angle and multilayer (Pt/C) with narrow period. Also, the advanced Kirkpatrick-Baez mirrors comprise two mirror pairs based on the Wolter type I and type III optics, respectively, to have sufficiently large magnification even at a compact setup with the whole length of 2 m (between a sample and a camera). The compactness makes it possible to apply the optics to laboratory-based X-ray microscopes, which is another ongoing project. A performance test using a Siemens star chart at an X-ray energy of 8 keV was performed in SPring-8 BL29XUL. The results showed lines with approximately 30-nm width could be resolved. Also, tests of stability and energy dependence confirmed usability of this system.

Image restoration is a process used to remove blur (from different sources like object motion or aberrations) from images by either non-blind or blind-deconvolution. The metrics commonly used to quantify the restoration process are peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). Often only a small sample of test images are used (like Lena or the camera guy). In optical design research PSNR and SSIM are not normally used, here image quality metrics based on linear system theory (e.g. modulation transfer function, MTF) are used to quantify optical errors like spherical or chromatic aberration. In this article we investigate how different image restoration algorithms can be quantified by applying image quality metrics. We start with synthetic image data that is used in camera test stands (e.g. Siemens star etc.), apply two different spatially variant degradation algorithms, and restore the original image by a direct method (Wiener filtering within sub-images), and by an iterative method (alternating direction method of multipliers, ADMM). Afterwards we compare the quality metrics (like MTF curves) for the original, the degraded and the restored image. As a first result we show that restoration algorithms sometimes fail in dealing with non-natural scenes, e.g. slanted-edge targets. Further, these first results indicate a correlation between degradation and restoration, i.e. the restoration algorithms are not capable of removing the optically relevant errors introduced by the degradation, a fact neither visible nor available from the PSNR values. We discuss the relevance in the context of the automotive industry, where image restoration may yield distinct advantages for camera-based applications, but testing methods rely on the used image quality metrics.

The purpose of the presented research was to establish a methodology that would allow the registration of hyperspectral images with a defined spatial resolution on a horizontal plane. The results obtained within this research could then be used to establish the optimum sensor and flight parameters for collecting aerial imagery data using an UAV or other aerial system. The methodology is based on an user-selected optimal camera exposure parameters (i.e. time, gain value) and flight parameters (i.e. altitude, velocity). A push-broom hyperspectral imager- the Headwall MicroHyperspec A-series VNIR was used to conduct this research. The measurement station consisted of the following equipment: a hyperspectral camera MicroHyperspec A-series VNIR, a personal computer with HyperSpec III software, a slider system which guaranteed the stable motion of the sensor system, a white reference panel and a Siemens star, which was used to evaluate the spatial resolution. Hyperspectral images were recorded at different distances between the sensor and the target- from 5m to 100m. During the registration process of each acquired image, many exposure parameters were changed, such as: the aperture value, exposure time and speed of the camera’s movement on the slider. Based on all of the registered hyperspectral images, some dependencies between chosen parameters had been developed: - the Ground Sampling Distance – GSD and the distance between the sensor and the target, - the speed of the camera and the distance between the sensor and the target, - the exposure time and the gain value, - the Density Number and the gain value. The developed methodology allowed us to determine the speed and the altitude of an unmanned aerial vehicle on which the sensor would be mounted, ensuring that the registered hyperspectral images have the required spatial resolution.

With advantages of operational convenience, quick process and economic feasibility, the availability of UAV Photogrammetry is increasing significantly in many different fields of acquiring geospatial information recently. In particular, it is being applied even to a cadastral surveying, including production of orthophotos and large scale topographic maps that require highly precise positional information. However, a quality verification process of UAV images should be preceded, because they are quite inhomogeneous by acquiring under strong variable conditions such as a rapid change of flying heights and exposure stations. In this paper, as part of a quality assurance plan for UAV images to ensure high quality products by UAV-Photogrammetry, a simple analysis method for the spatial resolution of UAV images was presented. To do this, portable resolution test charts in a pattern of Siemens star and Tri-bar were installed in a test area before imaging, and then visual resolution and GSD (Ground Sample Distance) appeared on the photographed images were measured. UAV images were taken with both payloads of fixed and rotary wing. The flight heights were 130 m and 260 m for fixed wing, and just 130 m for rotary wing. The results showed that a GSD of UAV image from fixed wing installed with a camera (Canon IXUS 127 HS) is 4.08 cm at the flying height of 130 m, 7.94 cm at 260 m, and a GSD of UAV image from rotary wing installed with a camera (Sony NEX-5N) is 4.10 cm at the flying height of 130 m. These values are almost consistent with theoretical resolution. The method proposed in this study is considered as a very useful for the applying of spatial resolution analysis of UAV images.

A new type of scintillator screen consisting of a ZnS scintillator with a dysprosium neutron converter is explored in a joint effort between Idaho National Laboratory (INL) and Paul Scherrer Institute (PSI). In contrast with a traditional prompt 6Li or Gd converters, a dysprosium converter generates a latent image as neutron activated dysprosium produces an isotope which decays with half-lives of 1.26 min and 2.3 h and the decay radiation excites the ZnS scintillator. The activated scintillator screen is physically transported out of the neutron beam and away from radioactive samples into the imaging apparatus and emits photons as the screen decays, which are read by a digital camera. This technology bridges the gap between traditional indirect transfer radiography and modern digital camera-based systems. This paper describes initial development of dysprosium-based scintillator screens and the results of initial tests performed at PSI. Some screen variants exhibit sufficient light output to produce good quality radiographs in a matter of minutes. The basic spatial resolution measured using a Siemens star is approximately 300 μ m . This work demonstrates for the first time that indirect digital transfer method neutron imaging is a plausible method of imaging highly radioactive sources such as irradiated nuclear fuel.

Focus Variation (FV) has been successfully employed for the three-dimensional measurement of rough surfaces. The technique relies on scanning the sample under inspection across the depth of focus of a high numerical aperture microscope objective, while computing the local contrast of its surface. Only those samples with sufficient texture will provide a usable axial response to compute its height location, limiting the application of Focus Variation to optically rough surfaces. Active illumination Focus Variation (AiFV) introduces an artificial texture on the field diaphragm position which is superimposed onto the surface. The benefit is a usable axial response, even when scanning an optically smooth surface, while minimizing the evaluation window of the focus operator close to the spatial autocorrelation length of the artificial texture. In this paper, we show the development of an Active illumination Focus Variation on an existing confocal microscope using Microdisplay Scanning technology. We analyzed the performance of AiFV on smooth surfaces with low frequency components, such as traceable Step Height or Type B2 roughness standards. Higher frequency samples such as random direction roughness standards or high-resolution targets are affected by the lateral resolution loss inherent on the AiFV technique. In this paper, we compare the lateral resolution limit of AiFV and Confocal Microscopy with the use of a Siemens Star specimen for a range of microscope objectives with numerical apertures from 0.3 to 0.95. Its influence on the computed ISO 25178 parameters on random surfaces is shown.

Full-field x ray nano-imaging (FXNI) is one of the most powerful tools for in-situ, non-destructive observation of the inner structure of samples at the nanoscale. Owing to the high flux density of the third-generation synchrotron radiation facility, great progress is achieved for FXNI and its applications. Up to now, a spatial resolution of 20 nm for FXNI is achieved. Based on the user operation experiences over the years at the Shanghai Synchrotron Radiation Facility (SSRF) x ray imaging beamline, we know lots of user experiments will rely on a large range of spatial resolutions and fields of view (FOVs). In particular, x ray microscopes with a large FOV and a moderate spatial resolution of around 100 nm have a wide range of applications in many research fields. Driven by user requirements, a dedicated FXNI system is designed and constructed at the SSRF. This microscope is based on a beam shaper and a zone plate, with the optimized working energy range set to 8–10 keV. The experimental test results by a Siemens star pattern demonstrate that a spatial resolution of 100 nm is achieved, while an FOV of 50 μm is obtained.

In LA-ICP-MS imaging mostly lateral resolution is considered, but this work will show that linear artifacts with an angular aspect to the line scan direction may have a different spatial resolution, depending on the blur introduced by LA sampling and aerosol washout/transfer. This implies that upon scanning an irregularly shaped artifact, the spatial resolution in different locations may vary, the severity of which will be a function of the amount of “smearing” induced by the LA-ICP-MS system, invariably related to the design of the LA cell and aerosol washout/transfer efficiency. As reported previously (DOI: 10.1021/acs.analchem.6b02052), blur can be expressed as a convolution of the input image (representing the 2D elemental distribution) with point (PSF) and line (LSF) spread functions associated with ablation crater profiles and ICP-MS profiles of single pulses, respectively. Based on empirically derived PSFs and LSFs, and using a numerical calculation approach, the continuous-scanning LA-ICP-MS output of an angular-sensitive radial resolution target (Siemens star) was simulated to visualize the angular resolution dependency associated with ablation cell characteristics.

A cross-correlation algorithm, which enables the obtaining of the velocity field in the flow with a spatial resolution up to a single pixel per vector, has been realized in the work. It gives new information about the structure of microflows as well as increases considerably the accuracy of the measurement of the flow velocity field. In addition, the realized algorithm renders information about the velocity fluctuations in the flow structure. The algorithm was tested on synthetic data at a different number of test images the velocity distribution on which was specified by the Siemens star. The experimental validation was done on the data provided within the international project “4th International PIV Challenge”. Besides, a detailed comparison with the Particle Image Velocimetry algorithm, which was realized previously, was carried out.

The ground resolved distance (GRD) of an imaging sensor, i.e. the size of the smallest element distinguishable on acquired imagery, is one of the most important sensor quality assessment factors, as it is directly linked to the amount of information that can be derived from the end product. The paper is a review of a wide variety of calibration targets used for determining the spatial resolution of remote sensing sensors. The author provides a description of calibration targets used historically and then moves on to high-frequency targets used for high-resolution remote sensing imaging equipment. As analysis is made which of these types of targets are best suited for UAV sensors, taking into account parameters very specific to UAVs: frame size, small GSD values and low flight stability.

A V-shape Bio-Transfer-Standard (V-BTS), developed and produced at the University of Helsinki (UH), was measured in two laboratories. In comparison to Siemens Star calibration specimens, the V-BTS performs better at high lateral frequencies close to the diffraction limit of the optical instrument. This peunits deteunining of the Instrument Transfer Function (ITF). The V-BTS features two lipid bilayer steps that partly overlap each other at an angle of 20, with an average height of 4.6 +/- 0.1 nm. The Round Robin (RR) test aims to determine whether the V-BTS and the developed application protocol work with different optical profilers in different laboratories. First the artefact was measured at Sensofar-Tech, S.L. using an S-neox profiler working in Phase Shifting Interferometry mode. Then V-BTS was measured at UH using a custom-built Scanning White Light Interferometer. All measurements done by four different operators at the two laboratories have a range or standard deviation of 0.1 nm which agrees with the theoretical estimates and with measurements done using an atomic force microscope and with a surface plasmon resonance based instrument. The RR results show the applicability of the V-BTS for calibration and for ITF characterization of 3D optical profilers.

The Institute for Optical Sensor Systems was involved in many international space projects in recent years. These include, for example, the fokal plane array (FPA) of the hyperspectral sensors ENMAP or Sentinel-4, but also the FPA for the high resolution FPA for Kompsat-3. An important requirement of the customer is the measurement of the detector MTF for different wavelengths. A measuring station under clean room conditions and evaluation algorithms was developed for these measurements. The measurement setup consist of a collimator with slit target in focus for illumination at infinity, a gimbal mounted detector facing an auxiliary lens in front, a halogen lamp with monochromator or filter, as well as optical and electrical ground support equipment. Different targets and therefore also different measurement and data evaluation opportunities are possible with this setup. Examples are slit, edge, pin hole but also a Siemens star. The article describes the measurement setup, the different measuring and evaluation procedures and exemplary results for Sentinel-4 detector.

We present a coherent imaging setup for extended samples achieving record-high resolution for non-periodic samples. A Siemens star pattern is imaged and the Rayleigh criterion is used to provide a reliable sub-50 nm resolution claim.

We present results of recent development of the color X-ray camera, type SLcam®, allowing detection of X-ray images with few microns resolution. Such spectral resolution is achieved with the use of high-quality polycapillary optics combined with sub-pixel resolution. Imaging of Siemens star resolution test chart reveals that the resolution limit of SLcam® can go down to nearly 5μm. Several real sample examples of measurements carried out at the laboratory, synchrotron, and particle-induced X-ray emission beamlines are shown. This is the first time SLcam® is used as particle-induced X-ray emission detector. Copyright © 2015 John Wiley & Sons, Ltd.

Here we present results stemming from the first prototype of the Neutron Microscope instrument at Paul ScherrerInstitut (PSI). The instrument is based on a very thin gadolinium oxysulfide (Gd2O2S:Tb+) scintillator screen and a magnifying optics. The Neutron Microscope prototype has been tested at the ICON and the BOA beamlines at PSI and sub-10 μm features can be clearly resolved on a focussed ion beam (FIB) enhance test object – a gadolinium-based Siemens star. The spatial resolution of the images of the gadolinium-based Siemensstar assessed by Fourier ring correlation was about 7.6 μm. The outlook for future improvement of the Neutron Microscope system is presented.

The material lithium indium diselenide, a single crystal neutron sensitive semiconductor, has demonstrated its capabilities as a high resolution imaging device. The sensor was prepared with a 55 μ m pitch array of gold contacts, designed to couple with the Timepix imaging ASIC. The resulting device was tested at the High Flux Isotope Reactor, demonstrating a response to cold neutrons when enriched in 95% 6 Li. The imaging system performed a series of experiments resulting in a

Hard x-ray imaging methods are routinely used in two and three spatial dimensions to tackle challenging scientific questions of the 21st century, e.g. catalytic processes in energy research and bio-physical experiments on the single-cell level [1–3]. Among the most important experimental techniques are scanning SAXS to probe the local orientation of filaments and fluorescence mapping to quantify the local composition. The routinely available spot size has been reduced to few tens of nanometres; but the real-space resolution of these techniques can degrade by (i) vibration or drift, and (ii) spreading of beam damage, especially for soft condensed matter on small length scales. We have recently developed new Multilayer Zone Plate (MZP) optics for focusing hard (14 keV) and very hard (60 keV to above 100 keV) x-rays down to spot sizes presumably on 5 or 10nm scale. Here we report on recent progress on a new MZP based sample scanner, and how to tackle beam damage spread. The Eiger detector synchronized to a piezo scanner enables to scan in a 2D continuous mode fields of view larger than 20μm squared, or for high resolution down to (virtual) pixel sizes of below 2nm, in about three minutes for 255×255 points (90 seconds after further improvements). Nano-SAXS measurements with more than one million real-space pixels, each containing a full diffraction image, can be carried out in less than one hour, as we have shown using a Siemens star test pattern.

The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

Multi-day tracking of cells in culture systems can provide valuable information in bioscience experiments. We report the development of a cell culture imaging system, named EmSight, which incorporates multiple compact Fourier ptychographic microscopes with a standard multiwell imaging plate. The system is housed in an incubator and presently incorporates six microscopes, imaging an ANSI standard 6-well plate at the same time. By using the same low magnification objective lenses (NA of 0.1) as the objective and the tube lens, the EmSight is configured as a 1:1 imaging system that, providing large field-of-view (FOV) imaging (5.7 mm × 4.3 mm) onto a low-cost CMOS imaging sensor. The EmSight improves the image resolution by capturing a series of images of the sample at varying illumination angles; the instrument reconstructs a higher-resolution image by using the iterative Fourier ptychographic algorithm. In addition to providing high-resolution brightfield and phase imaging, the EmSight is also capable of fluorescence imaging at the native resolution of the objectives. We characterized the system using a phase Siemens star target, and show four-fold improved coherent resolution (synthetic NA of 0.42) and a depth of field of 0.2 mm. To conduct live, long-term dopaminergic neuron imaging, we cultured ventral midbrain from mice driving eGFP from the tyrosine hydroxylase promoter. The EmSight system tracks movements of dopaminergic neurons over a 21 day period.

To carry on neutron imaging researches (radiography/tomography), we built a Cold Neutron Radiography Facility (CNRF), based on the China Mianyang Research Reactor (CMRR) at Institute of Nuclear and Chemistry (INPC). This CNRF system utilizes cold neutrons from the C1 neutron guide. The facility consists of beam shutter, flight tubes, beam limiter, object handling system, imaging system, beam stop and data acquisition system. The maximum neutron flux at the sample position is 6 × 106 n/cm2/s, approximately. There are seven pinholes in the collimator system, to offer a possible L/D from 200 to 1300. With different imaging lenses, the imaging system could provide four different FOVs. The performance parameters are tested by Siemens Star and ASTM standard devices-beam purity indicator (BPI) and image sensitivity indicator (SI). Our results show the resolution of CNRF is better than 20 μ m (i.e. 25lp/mm), and its typical radiography image is of Category-I, as defined in ASTM E545.

Soft UV NIL as replication technique was used to replicate sub 100 nm structures. The aim of this work is the stamp production and the replication of structures with dimensions smaller than 100 nm in a simple manner. Composite stamps composed of two layers, a thin hard PDMS h PDMS layer supported by a thick soft PDMS s PDMS layer are compared to common s PDMS stamps regarding the resolution by using a Siemens star star burst pattern as test structure. The master is fabricated by Electron Beam Lithography EBL in a 140 nm thick PMMA resist layer. The stamp is molded directly from the structured resist, without any additional anti sticking treatment. Therefore the resist thickness determines the aspect ratio, which is 1.5 at the resolution limit. The replication is done in a UV curing cycloaliphatic epoxy material. The employed test structure provides good comparability, the resolution limit at a glance, and it integrates a smooth transition from micro to nanostructures. Therefore it is a capable structure to characterize the UV NIL

In this paper we present and investigate binary phase diffraction gratings whose phase reliefs have form of rosettes-the so-called rosette gratings. They are constructed by the equiphase lines of the cosine-profiled phase Siemens star axicon-a hybrid optical element consisting of an axicon and a phase optical element with azimuthal cosine profile. It is shown that the rosette gratings transform the incident Gaussian laser beam into a sum of odd-diffraction orders beams, nondiverging in defined propagation intervals. The amplitude and intensity distributions of the separate diffraction orders, as well as the interference between them are studied. Under certain conditions these gratings can act as suitable substitutes for the cosine-profiled phase Siemens star axicons in their applications.