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This work introduces, for the first time, a millimeter-wave imaging system with a “synthetic” ultra-wide imaging bandwidth of 98 GHz to provide the ultra-high resolutions required for early-stage skin cancer detection. The proposed approach consists of splitting the required ultra-wide imaging bandwidth into four sub-bands, and assigning each sub-band to a separate imaging element, i.e., an antenna radiator. Each of the sub-band antennas transmits and receives signals only at its corresponding sub-band. The captured signals are then combined and processed to form the image of the target. For each sub-band, a Vivaldi tapered slot antenna fed with a combination of substrate-integrated waveguide and coplanar waveguide is designed and microfabricated. Design techniques are also provided for the four similarly-shaped sub-band antennas for achieving excellent impedance matches ( $S_{11}$ < –10 dB) and nearly constant gains of 10 dBi over the entire 12–110 GHz bandwidth. The design procedure is validated by comparing the simulated results with measurements performed on the fabricated prototypes. Excellent agreements are obtained between simulations and measurements. Finally, the feasibility of detecting early-stage skin tumors in three dimensions is experimentally verified by employing the sub-band antennas in a synthetic ultra-wideband imaging system with a bandwidth of 98 GHz. Two separate setups, each comprising a dispersive skin-mimicking phantom as well as two dispersive spherical tumors, are constructed for imaging experiments. Lateral and axial resolutions of 200 μm are confirmed, and a successful reconstruction of the spherical tumors is achieved in both cases.

To evaluate the technical performance of an ultra-high-resolution CT (UHRCT) system.The physico-technical capabilities of a novel commercial UHRCT system were assessed and compared with those of a current-generation multi-detector (MDCT) system. The super-high-resolution (SHR) mode of the system uses 0.25 mm (at isocentre) detector elements (dels) in the in-plane and longitudinal directions, while the high-resolution (HR) mode bins two dels in the longitudinal direction. The normal-resolution (NR) mode bins dels 2 × 2, resulting in a del-size equivalent to that of the MDCT system. In general, standard procedures and phantoms were used to perform these assessments.The UHRCT MTF (10% MTF 4.1 lp/mm) is twice as high as that of the MDCT (10% MTF 1.9 lp/mm), which is comparable to the MTF in the NR mode (10% MTF 1.7 lp/mm). The width of the slice sensitivity profile in the SHR mode (FWHM 0.45 mm) is about 60% of that of the MDCT (FWHM 0.77 mm). Uniformity and CT numbers are within the expected range. Noise in the high-resolution modes has a higher magnitude and higher frequency components compared with MDCT. Low-contrast visibility is lower for the NR, HR and SHR modes compared with MDCT, but about a 14%, for NR, and 23%, for HR and SHR, dose increase gives the same results.HR and SHR mode scanning results in double the spatial resolution, with about a 23% increase in dose required to achieve the same low-contrast detectability.• Resolution on UHRCT is up to twice as high as for the tested MDCT. • With abdominal settings, UHRCT needs higher dose for the same low-contrast detectability as MDCT, but dose is still below achievable levels as defined by current diagnostic reference levels. • The UHRCT system used in normal-resolution mode yields comparable resolution and noise characteristics as the MDCT system.

Optical coherence tomography (OCT) has recently been demonstrated as a powerful tool to image through pharmaceutical film coatings. Majority of the existing systems can, however, resolve film coatings for thickness greater than 10 µm. Here we report on an ultra-high-resolution (UHR) OCT system, with 1 µm axial and 1.6 µm lateral resolutions, which can resolve thin coatings at approximately 4 µm. We further demonstrate a novel application of the system for differentiating generic and branded suppliers of paracetamol tablets.

In this paper, we demonstrate multicolor OLEDs patterned sideby-side by photolithography. 1250 ppi arrays with 10 μm subpixel pitch are shown. The chemically amplified, i-line photoresist enables submicron pitch and aperture ratio above 60%. OLED photolithography paves the road to cost-effective, full-color displays with 4K and 8K resolution.

Optical absorption spectroscopy of non-equilibrium plasmas using a supercontinuum laser combined with a laser line tunable filter and a HyperFine spectrometer is examined. Owing to the 2 and Ar 1s4 (Paschen notation) number densities. At a pressure of 1 Torr, a discharge current of 20 mA, and an absorption length of 18 cm, the analysis of the Ar 2p3-1s2 and Ar 2p8-1s4 absorption lines at respectively 840.8 nm and 842.5 nm resulted in number densities of n 1 s 2 = 5.5 × 1015 m−3 and n 1 s 4 = 1.1 × 1016 m−3 and a neutral gas temperature of T g = 340 K. These values are typical of DC discharges operated under similar experimental conditions. While the fractional absorption of both lines decreased with decreasing optical absorption path, the number densities remained the same, as expected. Finally, the number densities increased with increasing discharge current, a result also coherent with the literature.

A prototype spectrograph using a Virtually Imaged Phased Array (VIPA) as the main dispersion element is presented, and its performance is fully examined in our laboratory. The single-mode, fiber-fed spectrograph with simultaneous wavelength calibration possesses a spectral resolution well in excess of while the size of the VIPA is several orders of magnitude smaller than that of a conventional échelle with comparable resolution. In laboratory tests, the VIPA-based instrument with a homemade Yb:fiber ring laser frequency comb demonstrates a mode-to-mode tracking stability of 41 cm s−1 over a period of 6 hr. The VIPA spectrograph has promising applications in various astronomical observations in which ultra-high resolution and calibration precision are imperative, such as solar physics research, exoplanet searching with the radial velocity method, and O2 detection in the atmosphere of Earth-like planets. Ultimately, feasible optimizations for night-sky observations under seeing limited conditions are discussed.

We analyze the influence of intrinsic polarization alignment on image quality and axial resolution employing a broadband 840 nm light source with an optical bandwidth of 160 nm and an output power of 12 mW tailored for spectral-domain optical coherence microscopy (SD-OCM) applications. Three superluminescent diodes (SLEDs) are integrated into a 14-pin butterfly module using a free-space micro-optical bench architecture, maintaining a constant polarization state across the full spectral output. We demonstrate superior imaging performance in comparison to traditionally coupled-SLED broadband light sources in a teleost model organism in-vivo.

We demonstrate microwave photonic radar with post-bandwidth synthesis, which can realize target detection with ultra-high range resolution using relatively small-bandwidth radio frequency (RF) frontends. In the proposed radar, two temporal-overlapped linear frequency-modulated (LFM) signals with the same chirp rate and different center frequencies are transmitted. By post-processing the de-chirped echoes in the receiver, a signal equivalent to that de-chirped from an LFM signal with the combined bandwidth is achieved. In a proof-of-concept experiment, two LFM signals with bandwidths of 8.4 GHz are exploited to achieve radar detection with an equivalent bandwidth of 16 GHz, and a range resolution of 1 cm is obtained.

Microwave photonic technology is a promising solution to overcome the bandwidth limitations in radar and communication systems. Recently, photonics-based radar has attracted lots of attention because of its ultra-high resolution enabled by the large operation bandwidth. In this report, we review our recent investigations on a photonics-based radar and its application in target imaging. The radar generates broadband linear frequency modulation signal by photonic frequency multiplication, and implements de-chirping in the receiver by microwave photonic frequency mixing. Its large operation bandwidth and real-time signal processing capability make it possible for realize ultra-high resolution and real-time imaging. With an established Ka-band 12 GHz bandwidth photonics-based radar, a range resolution as high as 1.3 cm is achieved. High-resolution and real-time inverse synthetic aperture radar (ISAR) imaging is also demonstrated through a turntable imaging experiment and a field trial target imaging experiment. The results prove that photonics-based radar is an effective solution to overcome the limitations on operation bandwidth and processing speed of current radar imaging technologies. To further improve the radar imaging performance such as a higher cross-range resolution, we propose a possible solution by constructing a photonics-based multiple input multiple output (MIMO) radar, which combines the photonics-based radar with the MIMO technique. Through numerical simulations, we show the advantage of radar imaging with the photonics-based MIMO radar.

Article describes instrumental features of the 12-ARPES endstation and beamline at BESSY-II which are relevant for planning and preparation of experiments.

We demonstrate a photonics-based Ka-band radar system with 12 GHz bandwidth by optical signal generation and de-chirp processing. Inverse synthetic aperture radar imaging with a range resolution as high as ∼1.3 cm high-resolution is achieved.

In vivo optical coherence tomography (OCT) image of angioma (A). Thin red arrows point to a blood vessel (BV). Non-invasive and quantitative estimations for the delineation of sub-surface tumor margins could greatly aid in the early detection and monitoring of the morphological appearances of tumor growth, ensure complete tumor excision without the unnecessary sacrifice of healthy tissue, and facilitate post-operative follow-up for recurrence. In this study, a high-speed, non-invasive, and ultra-high-resolution spectral domain optical coherence tomography (UHR-SDOCT) imaging platform was developed for the quantitative measurement of human sub-surface skin mass. With a proposed robust, semi-automatic analysis, the system can rapidly quantify lesion area and shape regularity by an en-face-oriented algorithm. Various sizes of nylon sutures embedded in pork skin were used first as a phantom to verify the accuracy of our algorithm, and then in vivo, feasibility was proven using benign human angiomas and pigmented nevi. Clinically, this is the first step towards an automated skin lesion measurement system.

A new phase controlled method is proposed to realize ultra-high resolution laser beam deflection on the physics of coherence between sub-apertures on one device of liquid crystal optical phased array (LC-OPA). Sub-apertures are electronically switchable and divided from a uniform device of LC-OPA. In the approach of sub-aperture coherence (SAC), numerical simulation results show the characteristics of far field including SAC steering step and angular width. Meanwhile, the method of SAC has also been verified by experiments showing a good agreement with the simulation results of ultra-high resolution beam deflection.

BOE has lunched the worl's first 10K4K ultra high resolution LCD. This display has diagonal size of 82 inch and resolution of 1020 x 4 320. Its pixel density is 135 p pi. This display shows excellent characteristics, such as high color gamut, high contrast ratio and low power consumption.

FastSPECT III is a recently developed ultra-highresolution small-animal SPECT imaging system. With 20 CCDbased intensified quantum-imaging cameras (iQID) and 250micron diameter platinum pinhole apertures, this stationary SPECT system offers $\sim 350$ microns isotropic linear resolution. This paper presents a novel system calibration method for FastSPECT III and other high-resolution stationary pinholeSPECT systems. The performance of the new system calibration method was evaluated using multi-bed-position MLEM reconstruction and helically-scanned objects. Originally designed for high-resolution rodent brain imaging to study neurological pathologies, FastSPECT III now offers whole-body mouse imaging capabilities with ultra-high spatial resolution.

The purpose of this study was to compare the physical characteristics of Low Energy High Resolution (LEHR), Low Energy Ultra High Resolution (LEUHR) and Medium Energy Low Penetration (MELP) collimators for simultaneous 99mTc and 123I imaging. MELP collimator performed well with 123I high-energy gamma photons, but low resolution makes it unsuitable to use for acquisition of small structures such as parathyroid adenomas. LEUHR collimators optimized for 99mTc have highest resolution, but the differences in septal penetration and sensitivity in favor of LEHR collimator needs to be tested with specific parathyroid phantoms.

Supercontinuum (SC) light is a well-established technology, which finds applications in several domains ranging from chemistry to material science and imaging systems [1-2]. More specifically, its ultra-wide optical bandwidth and high average power make it an ideal tool for Optical Coherence Tomography (OCT). Over the last 5 years, numerous examples have demonstrated its high potential [3-4] in this context. However, SC light sources present pulse-to-pulse intensity variation that can limit the performance of any OCT system [5] by degrading their signal to noise ratio (SNR). To this goal, we have studied and compared the noise of several SC light sources and evaluated how their noise properties affect the performance of Ultra-High Resolution OCT (UHR-OCT) at 1300 nm. We have measured several SC light sources with different parameters (pulse length, energy, seed repetition rate, etc.). We illustrate the different noise measurements and their impact on a state of the art UHR-OCT system producing images of skin. The sensitivity of the system was higher than 95 dB, with an axial resolution below 4μm.

We developed an experimental approach for identifying and eliminating aberrations even in the presence of strong multiple light scattering, and demonstrated 600 nm spatial resolution to the imaging depth of 7 scattering mean free paths.

A new article presents an ultra-stable, ultra-fast X-ray microscope that will take advantage of the 100-fold increase in photons produced after the upgrade of the Advanced Photon Source.A new article presents an ultra-stable, ultra-fast X-ray microscope that will take advantage of the 100-fold increase in photons produced after the upgrade of the Advanced Photon Source.

The tears on contact lenses are critical for maintaining clear vision, ocular comfort, and health. The lens on the eye needs to be wet on both sides, and the tears underneath the lens need to be exchanged continuously. It is very common for soft contact lens wearers to experience dry eye, especially in the afternoon after wearing the lens for a period of time.1,2 Studies showed that dry eye sensation is a common cause of contact lens drop-out.1,2 To evaluate contact lens fitting, observation of lens centration, movement, and coverage using slit lamp microscopy may not be enough to understand the cause of dry eye sensations. Lenses composed of different materials and designs may have unique fitting characteristics that can impact pre- and post-lens tear films and the relationship between the lens edge and ocular surface. These features may result in different levels of ocular comfort. Changes in tear distribution and dynamics during lens wear remain unknown due to the extreme difficulty of simultaneously imaging both tears and hard or soft contact lenses. Technologic advancements have enabled the development of ultra-high resolution optical coherence tomography (OCT). The purpose of this study was to apply this new technology to better understand tear distribution and dynamics in contact lens wearers. This article report the results of in situ imaging of the tear film on the lens surfaces and at the edges where they interface with the tears and the ocular surface.

The 0.3 mm-pixel-pitch ultra-high-resolution PDP is being developed for use in the “Super Hi-Vision” broadcasting system with over 4,000 scanning lines. In this study, we used three-dimensional discharge simulation to compare the vacuum ultraviolet (VUV) radiation characteristics of box- and stripe-type cells in the PDP in order to improve the luminous efficiency and VUV crosstalk. The luminous efficiency of the box-type cell was 22% higher than that of stripe-type cell in a gas composition of Ne-Xe (5 %) at 67 kPa (500 Torr) due to the lower discharge current. The stripe-type cell had 19% VUV crosstalk to the phosphor surfaces of the neighboring vertical cells. Use of the box-type cell, which can intercept the VUV crosstalk, is most effective for achieving high resolution and enhancing efficiency.

Ibaraki Biological Crystal Diffractometer is under construction at J-PARC as a pulsed-neutron diffractometerfor biological macromolecules. This diffractometer is designed to measure crystals up to 150 A in unitcell dimensions with the measurement efficiency of 100 times better than that of the present diffractometer BIX-4 at JRR-3 in JAEA. The complementarity to the ultra-high resolution X-ray analysis will bereferred to after showing the recent development of neutron and X-ray protein crystallography.

We demonstrate measured X-ray dose efficiency results from a 5.6-μm × 6.25-μm pixel-pitch direct-conversion amorphous selenium/CMOS hybrid X-ray imager. Compared to existing scintillator-based imagers, our approach enables up to 100x gains in DQE at spatial frequencies of 20–60 cycles/mm, which could radically accelerate bioengineering research. The measured MTF is 50% at 32 cycles/mm, corresponding to a 16-μm effective object size. We also demonstrate a MTF model which confirms experimental results with an RMS error of 0.02.

This article numerically verifies ultra-high-resolution confocal millimeter-wave imaging for biomedical applications for the first time. A system with an ultra-wide bandwidth of more than 85 GHz is proposed to provide the ultra-high resolutions required for biomedical imaging applications. The feasibility of detecting early-stage tumors in three dimensions is shown using realistic numerical phantoms. A suitable image formation algorithm is developed and applied to the data. Successful resolution of spherical tumors is achieved in the obtained images both axially and laterally.

Purpose The extent of activity of an intravitreal injected drug is linked to its dispersion within the vitreous body. Researchers have been trying to visualize dispersion of intravitreal injected solutions using Indian ink or fluorescein, either with subsequent dissection or with endoillumination, both invasive methods that could influence the dispersion pattern. Therefore, this pilot study aims at investigating and identifying the best minimal invasive imaging method for visualizing the dispersion of an intravitreal injected solution. Methods To determine the optimal imaging concentration, a series of 5 enucleated porcine eyes were injected with 0.1 cc of 100%, 50%, 25%, 20% and 10% standard iodium contrast medium, respectively. Injections were made using a standard 1 cc syringe and 30 gauge needle at 3.5 mm from the limbus aiming at the center of the globe. Subsequently, the dispersion of the contrast agent was monitored using high resolution imaging methods: mammography and ultra high resolution computed tomography (UHRCT). For the latter, 3D reconstructions were rendered. Results A 1:10 dilution mixture combined optimal visualization contrast with low viscosity of the injection solution using radiographic ultrahigh resolution mammography. Both mammography and UHRCT images were taken from two eyes; one with a slow injection, the other with a fast injection. Conclusions 3D reconstructed UHRCT images were favored over 2D mammography images for dynamic imaging of the intravitreal solution dispersion.

Optical coherence tomography is an optical imaging technique that performs non-destructive cross-sectional imaging of micrometer-scale structures in samples. In this report, we demonstrated the visualization of inner structures in tomato fruits and leaves with ultra-high resolution optical coherence tomography (UHR-OCT) using fiber based laser source with ultra-broadband continuous spectrum around 1.7 μm wavelength. We confirmed that our UHR-OCT system allows us to perform cross-sectional imaging of tomato fruits and leaves at ∼ 2.8 μm axial resolution.

The goal of this study was to investigate the performance of 3D synchrotron differential phase contrast (DPC) imaging for the visualization of both macroscopic and microscopic aspects of atherosclerosis in the mouse vasculature ex vivo. The hearts and aortas of 2 atherosclerotic and 2 wild-type control mice were scanned with DPC imaging with an isotropic resolution of 15 μm. The coronary artery vessel walls were segmented in the DPC datasets to assess their thickness, and histological staining was performed at the level of atherosclerotic plaques. The DPC imaging allowed for the visualization of complex structures such as the coronary arteries and their branches, the thin fibrous cap of atherosclerotic plaques as well as the chordae tendineae. The coronary vessel wall thickness ranged from 37.4 ± 5.6 μm in proximal coronary arteries to 13.6 ± 3.3 μm in distal branches. No consistent differences in coronary vessel wall thickness were detected between the wild-type and atherosclerotic hearts in this proof-of-concept study, although the standard deviation in the atherosclerotic mice was higher in most segments, consistent with the observation of occasional focal vessel wall thickening. Overall, DPC imaging of the cardiovascular system of the mice allowed for a simultaneous detailed 3D morphological assessment of both large structures and microscopic details., Scientific Reports, 5, ISSN:2045-2322

UV and X-ray space-based interferometry will open unprecedented possibilities for spectral and spatial studies of a wide range of currently unresolvable interacting systems. Ultra-high angular resolution direct imaging of individual components and transport processes in interacting binary systems is essential for detailed studies and modeling of accretion and activity. Understanding the mass loss characteristics of both components, and the dynamics of the system as a function of time, will provide key inputs to evolutionary models and will revolutionize our view and understanding of the Universe.

Starting from the Sumitomo commercial platform NEB-33 resist, three new experimental negative tone chemical amplified resist (CAR) formulations have been developed, to push resolution below 40 nm in direct electron beam lithography. PEB temperatures and times have been optimized between 60 and 100 °C and, respectively, 20 and 120 s. Fourier transform infra red spectra have been performed and allowed us to follow the solvent and PAG concentration in order to optimize processes on all samples. As a consequence, 25-nm isolated lines have been resolved with these new chemical amplified resists.

We investigated the possibility of incorporating a liquid-crystal device into a gas ionization detector. After extensive R&D on several candidate liquid-crystal technologies, we developed some novel materials allowing twisted nematic liquid-crystal layers to be coupled directly to gas ionization counters. However, the resulting structures were unsuitable for large-scale or practical use. We tested several technologies known to result in mechanically-robust liquid crystal electrooptic layers, but found poor behavior in the detector context.

We present a novel ultra-high resolution Raman spectroscopy technique based in a Fabry-Pérot/triple spectrometer tandem with multichannel acquisition. We describe the system, detail the calibration process, and experimentally test the technique, showing that effective finesses in excess of 1000 are possible. The technique is specifically tailored for low intensity, complex and spectrally extended Raman spectra, providing shorter acquisition times with respect to similar tandem systems with monochannel detectors. Fil: Rozas, Guillermo. Comisión Nacional de Energía Atómica; Argentina. Comision Nacional de Energia Atomica. Gerencia del _rea de Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Laboratorio de Propiedades Opticas; Argentina Fil: Jusserand, Bernard. Universite Pierre et Marie Curie; Francia Fil: Fainstein, Alejandro. Comisión Nacional de Energía Atómica; Argentina. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Física de Metales; Argentina