The substantial alteration of the crystalline structure at 300°C and 400°C was the reason for the shifts in stability. The process of crystal structure transition is accompanied by an augmentation of surface roughness, a rise in interdiffusion, and the creation of compounds.

Auroral bands of N2 Lyman-Birge-Hopfield, exhibiting emission lines at 140-180 nm, have been imaging targets for numerous satellites, each requiring reflective mirrors. Mirrors, to provide good imaging, must possess both excellent out-of-band reflection suppression and high reflectance properties at the intended wavelengths. Non-periodic multilayer LaF3/MgF2 mirrors, functioning in two wavelength bands, 140-160 nm and 160-180 nm, respectively, were both designed and fabricated by our team. selleck inhibitor The multilayer was designed using a method that incorporated match design and a deep search method. The new wide-field auroral imager from China has incorporated our research, thereby reducing the requirement for transmissive filters in the optical assembly of their space payload, a direct consequence of the superior out-of-band rejection of the integrated notch mirrors. Our research, in addition, has opened up new possibilities for the engineering of reflective mirrors active in the far ultraviolet region.

High resolution and a large field of view are combined in lensless ptychographic imaging, along with the beneficial properties of small size, portability, and reduced cost, making it superior to traditional lensed imaging. Nevertheless, lens-free imaging systems are vulnerable to environmental disturbances and exhibit lower resolution in individual images compared to systems employing lenses, thereby necessitating a longer acquisition time to achieve a satisfactory outcome. For enhanced convergence rate and noise resistance in lensless ptychographic imaging, we propose, in this paper, an adaptive correction method. This method introduces adaptive error and noise correction terms into lensless ptychographic algorithms for faster convergence and a superior suppression of Gaussian and Poisson noise. To achieve reduced computational complexity and enhanced convergence, our method integrates the Wirtinger flow and Nesterov algorithms. Through simulation and experimentation, we showcased the effectiveness of our method for phase reconstruction in lensless imaging systems. This method is readily adaptable to other ptychographic iterative algorithm applications.

The pursuit of high spectral and spatial resolution in measurement and detection has encountered a persistent hurdle for a long period. Our measurement system, based on single-pixel imaging with compressive sensing, accomplishes excellent spectral and spatial resolution at once, and effectively compresses data. Our method's high spectral and spatial resolution represents a significant departure from the inherent conflict between these two parameters in conventional imaging practices. Within the scope of our experimental work, 301 spectral channels were collected from the 420-780 nm band, boasting a spectral resolution of 12 nm and a spatial resolution of 111 milliradians. Compressive sensing facilitates a 125% sampling rate for 6464p images, leading to a reduction in measurement time and realizing simultaneous high spectral and spatial resolution.

This feature issue, a continuation of the Optica Topical Meeting on Digital Holography and 3D Imaging (DH+3D) tradition, follows the meeting's conclusion. Current research interests in digital holography and 3D imaging, mirroring the topics covered in Applied Optics and Journal of the Optical Society of America A, are the focus of this work.

Space x-ray telescopes employing large field-of-view observations utilize micro-pore optics (MPO). X-ray focal plane detectors with visible photon detection features necessitate a robust optical blocking filter (OBF) within MPO devices to avert signal interference from visible photons. This investigation details the construction of equipment for measuring light transmission with great accuracy. The design specifications for the MPO plates, as measured by transmittance testing, demonstrably meet the requirement of a transmittance value below 510-4. The multilayer homogeneous film matrix model enabled us to predict likely combinations of alumina film thicknesses that showed good alignment with the OBF design.

Jewelry pieces' evaluation and identification suffer limitations from the neighboring gemstones and the metal mount. To promote a transparent jewelry market, this study recommends imaging-assisted Raman and photoluminescence spectroscopy for the measurement and characterization of jewelry. Sequentially, the system employs the image's alignment to measure multiple gemstones on a piece of jewelry automatically. The prototype, designed for non-invasive measurement, demonstrates the capacity to isolate natural diamonds from their laboratory-created counterparts and diamond substitutes. Besides this, the image facilitates the process of evaluating gemstone color and estimating its weight.

Commercial and national security sensing systems frequently encounter difficulties in environments characterized by low-lying clouds, fog, and other highly scattering elements. selleck inhibitor Highly scattering environments pose a challenge to the performance of optical sensors, indispensable for autonomous systems' navigation. Our past simulation work proved that polarized light can penetrate scattering environments, encompassing conditions similar to fog. Demonstrating a crucial advantage, circularly polarized light shows enhanced resilience in retaining its initial polarization state compared to linearly polarized light, throughout many scattering events and extensive ranges. selleck inhibitor Independent experimentation by other researchers recently corroborated this. We investigate the design, construction, and testing of active polarization imagers at the wavelengths of short-wave infrared and visible light within this work. We delve into multiple imager polarimetric configurations, emphasizing the importance of both linear and circular polarization. Realistic fog conditions at the Sandia National Laboratories Fog Chamber were used to evaluate the polarized imagers. Fog-penetrating range and contrast are demonstrably augmented by active circular polarization imagers over linear polarization imagers. Circularly polarized imaging demonstrably enhances contrast in typical road sign and safety retro-reflective films across a variety of fog densities, outperforming linearly polarized imaging. Crucially, this method permits penetration of fog by 15 to 25 meters further than linear polarization, highlighting a significant dependence on the interplay between polarization and target material characteristics.

Laser-induced breakdown spectroscopy (LIBS) is predicted to be crucial for real-time monitoring and closed-loop control of laser-based layered controlled paint removal (LLCPR) applied to aircraft skin. Despite the availability of other techniques, the LIBS spectrum necessitates rapid and accurate assessment, and the appropriate monitoring criteria must be established via machine learning algorithms. To monitor paint removal, this study develops a self-built LIBS platform, incorporating a high-frequency (kilohertz-level) nanosecond infrared pulsed laser. This platform collects LIBS spectral data during the laser-assisted removal of the top coating (TC), primer (PR), and aluminum substrate (AS). The continuous background of the spectrum was removed, and key features were extracted. This enabled the construction of a classification model for three spectral types (TC, PR, and AS) using a random forest algorithm. An experimental verification followed the establishment of a real-time monitoring criterion, using this classification model and multiple LIBS spectra. The results demonstrate a classification accuracy of 98.89%, and each spectrum's classification takes around 0.003 milliseconds. Monitoring results for the paint removal process concur with macroscopic and microscopic analysis of the samples. Overall, the research provides essential technical support for continuous monitoring and closed-loop control of LLCPR signals emanating from the aircraft's hull.

When experimental photoelasticity images are captured, the spectral interplay between the light source and the sensor used alters the visual information seen in the fringe patterns of the resulting images. The interaction may produce high-quality fringe patterns, yet also result in images with indiscernible fringes and inaccurate stress field reconstructions. The interaction assessment strategy involves measuring four handcrafted descriptors: contrast, a descriptor sensitive to image blur and noise, a Fourier-based image quality descriptor, and image entropy. By analyzing selected descriptors on computational photoelasticity images, the usefulness of the proposed strategy was demonstrably validated. Evaluating the stress field across 240 spectral configurations with 24 light sources and 10 sensors showed the achievable fringe orders. High values of the chosen descriptors were observed to correlate with spectral patterns that enhance the reconstruction of the stress field. The collective results demonstrate that the chosen descriptors are useful indicators for identifying positive and negative spectral interactions, which can potentially contribute to the improvement of photoelasticity image acquisition protocols.

For the petawatt laser complex PEtawatt pARametric Laser (PEARL), a novel front-end laser system optically synchronizes chirped femtosecond and pump pulses. By incorporating a broader femtosecond pulse spectrum and enabling precise temporal shaping of the pump pulse, the new front-end system provides a considerable enhancement in the stability of the parametric amplification stages within the PEARL system.

The daytime measurement of slant visibility is substantially impacted by atmospheric scattered radiance. This paper investigates the errors in atmospheric scattered radiance and their impact on the measurement of slant visibility. Considering the inherent challenges of error generation within the radiative transfer equation, a Monte Carlo-method-based approach to error simulation is presented herein.