Optical Quality Research Articles

Green InP Quantum Dots with High Brightness and Narrow Emission through Layer-by-Layer Modification with Aluminum.

InP quantum dots (QDs) show a unique promise for display and lighting applications. However, the synthesis of InP QDs with high optical quality is much more difficult compared to that of Cd-based QDs and Pb-based perovskites. Here, we established a layer-by-layer modification approach to improve the optical properties of the InP QDs. InP QDs with green emission were prepared using tris(dimethylamino)phosphine ((DMA)3P). By introducing aluminum isopropoxide (AIP) twice during the formation of the ZnSeS and ZnS shell layers, we increased the photoluminescence quantum yield (PLQY) of the resulting Al-modified InP/ZnSeS/ZnS QDs to 96%. The full-width-at-half-maximum (fwhm) could be narrowed to 37 nm. It was speculated that the introduction of Al could alleviate the charge mismatch between the cores and shells and passivate surface defects. In addition, AIP might form oxides on the outer layers of QDs, thus enhancing their stability. Moreover, the green light-emitting diode (LED) based on Al-modified InP/ZnSeS/ZnS QDs performed well with a maximum power efficiency of 28 lm/W. This work finds a way to obtain InP QDs of high brightness and narrow emission by modification in the midsynthetic process, which will inspire the synthesis of better InP QDs.

Influence of scleral lens removal and reapplication on fluid reservoir thickness and visual quality after 5h of lens wear.

Influence of scleral lens removal and reapplication on fluid reservoir thickness and visual quality after 5h of lens wear.

A color masterbatch assistance system for optimizing product color by masterbatch addition in injection molding of post-industrial recyclates

Abstract In injection molding, ensuring consistent optical part quality, in particular achieving identical color across the parts produced, is crucial. In the context of processing recycled materials, variations in the input material streams can pose challenges, requiring color masterbatch content to be adapted inline if a predefined reference color is to be achieved. This study presents a color assistance system that uses a sensor to measure the color of injection molded parts and to determine the optimal amount of masterbatch to be added for achieving a specified color for a defined material input stream. Testing of the system focused on post-industrial recyclate which had a color in the second color quadrant in the CIELAB color space. The system proved effective in regulating masterbatch contents to improve color consistency and can be employed for quality assurance in the injection molding process, particularly when using recycled materials.

Tunable White Light Emission from Transparent Nanophosphor Films Embedding Perovskite Lead Halide Nanostructures.

Exploring synergistic interactions between nanomaterials that can enhance their collective properties in ways that individual components cannot achieve represents an avenue for advancing beyond the current state of the art. This approach is particularly relevant in the context of ABX3 nanocrystals, where pursuing cooperation could help to overcome current challenges associated with light generation. Transparent photoluminescent coatings are developed by combining perovskite nanomaterials and porous scaffolds of high optical quality phosphor nanoparticles. Fine tuning of the spectral content of the emission is achieved with the photoexcitation wavelength, allowing the demonstration of white light emission with tunable hues.

High photon-phonon pair generation rate in a two-dimensional optomechanical crystal

Integrated optomechanical systems are a leading platform for manipulating, sensing, and distributing quantum information, but are limited by residual optical heating. Here, we demonstrate a two-dimensional optomechanical crystal (OMC) geometry with increased thermal anchoring and a mechanical mode at 7.4 GHz, well aligned with the operation range of cryogenic microwave hardware and piezoelectric transducers. The eight times better thermalization than current one-dimensional OMCs, large optomechanical coupling rates, g0/2π ≈ 880 kHz, and high optical quality factors, Qopt = 2.4 × 105, allow ground-state cooling (nm = 0.32) of the acoustic mode from 3 K and entering the optomechanical strong-coupling regime. In pulsed sideband asymmetry measurements, we show ground-state operation (nm < 0.45) at temperatures below 10 mK, with repetition rates up to 3 MHz, generating photon-phonon pairs at ≈ 147 kHz. Our results extend optomechanical system capabilities and establish a robust foundation for future microwave-to-optical transducers with entanglement rates exceeding state-of-the-art superconducting qubit decoherence rates.

Precision replication and quality analysis of the molded glass cylindrical lens array

Precision glass molding (PGM) is a well-established and cost-effective manufacturing process used to fabricate high-quality and high-precision optical elements with complex geometries, such as aspherical lens, microlens array, and microprisms. This study focuses on the replication quality of molded glass cylindrical lens arrays, which is critical for achieving exceptional precision and consistency in optical applications. The effect of process parameters on replication quality of the molded cylindrical lens array was studied. A 4 × 1 cylindrical lens array, fabricated using wire electrical discharge machining and polishing, served as the replication mold. The profile deviation and replication ratio were analyzed under different processing conditions using a surface profilometer, while optical quality was assessed through birefringence measurements and light transmission experiments. The results indicated that integrated control of molding parameters is vital for high-fidelity replication, with optimal conditions yielding a height deviation of approximately 4 nm and a filling ratio of 99.999% at 550 °C and 9.8 kN. Additionally, we observed that increased molding force reduces height deviation, while excessive molding temperatures can lead to increased profile deviation. The minimum profile deviation achieved was below 1 µm, and residual birefringence was found to be less than 10 nm. This work not only enhances the understanding of precision glass molding but also provides valuable insights for manufacturers to identify and mitigate potential defects, ultimately improving product reliability and supporting innovation in optical design.

Descriptor-based optical flow quality assessment and error model construction for visual localization

Descriptor-based optical flow quality assessment and error model construction for visual localization

Visual quality following FS-LASIK with Q-value-guided optimized monovision in patients with myopia and presbyopia: Custom-Q in treating myopia and presbyopia

Visual quality following FS-LASIK with Q-value-guided optimized monovision in patients with myopia and presbyopia: Custom-Q in treating myopia and presbyopia

Effect of Pupil, Spherical Aberration, Decentration, and Tilt on the Optical Performance of Five Different Monofocal IOLs.

To evaluate and compare the effect of pupil size, spherical aberration (SA), decentration, and tilt on the optical performance of five different monofocal intraocular lenses (IOLs). Four aspheric IOLs (Vivinex, Hoya; SN60WF, Alcon Laboratories, Inc; ZCB00, Johnson & Johnson Surgical Vision; Akreos Adapt AO, Bausch & Lomb) with different SA values and one spherical IOL (SN60AT, Alcon Laboratories, Inc) were tested using an OptiSpheric IOL PRO 2 optical bench. The IOL diopter was measured at different apertures. The optical quality of the IOLs was evaluated using the modulation transfer function (MTF), through-focus MTF, and images of the United States Air Force Target test with different apertures and corneal SA values. The IOLs were also measured while they were decentered and tilted. The smaller the aperture, the wider the through-focus MTF of all tested IOLs, and the best image quality was observed with a 3-mm aperture. The diopter of aspheric IOLs with negative SA were negatively correlated with aperture size, but the result was opposite for spherical IOLs. The IOL power difference was more than 0.50 diopters between different apertures. All aspheric IOLs had similar MTF curves with a 3-mm aperture. Aspheric IOLs had the best visual quality with the same or similar corneal SAs. Most of the tested IOLs had lower tolerances in tilt than in decentration. Pupil size, SA value, the degree of decentration, and tilt had different effects on the optical performance of aspheric IOLs. The results can provide guidance for surgeons in clinical practice. [J Refract Surg. 2025;41(3):e220-e230.].

Preparation, Characterization and Evaluation of the Antibacterial Activity of Ag Nanoparticles Embedded in Transparent Oxide Matrices

Daily exposure to contaminated environments and surfaces leads to serious health issues, increasing healthcare costs. Active materials that act against pathogens can effectively prevent their proliferation and contribute to increased protection against infections. In this contribution, nanostructured thin films containing silver are investigated, using SiO2 and TiO2 as transparent matrices to embed the Ag atoms. The thin transparent films were obtained via magnetron sputtering, using HiPIMS for Ag deposition and RF sputtering for oxides, in either an Ar or Ar/O2 environment. Atomic Force Microscopy provided information on coating topography and the thin films’ preferential growth on the textured polymer foil, X-Ray Diffraction highlighted the structural difference between different versions, Ultraviolet–Visible–Near-Infrared spectroscopy proved the thin films’ optical quality and their transparency and Energy-Dispersive X-ray Spectroscopy revealed the composition changes for different processes. The effect of O2 addition is analyzed and compared in terms of changes induced on the properties of the thin films. Following 24 h of incubation in a media containing 104 CFU/mL Escherichia coli, the TiO2+Ag sample with O2 addition showed the highest antibacterial effectiveness, as indicated by the largest inhibition zone. Experiments on selective media showed a hierarchy of efficiency, namely, TiO2+Ag+O2 &gt; TiO2+Ag &gt; SiO2+Ag.

Silver Nanocube Epitaxy via Nanogap-Induced Electrostatics.

Silver nanostructures are highly valued in nanophotonic devices due to their appealing plasmonic properties and affordability relative to gold. Yet, fabricating high-quality, monocrystalline silver nanostructures, with full control over the shape, is challenging. A mild, liquid-phase method for the epitaxial welding of adjacent monocrystalline silver nanocubes in reductant-free conditions is introduced to prevent the formation of detrimental nuclei on the surface that can degrade the nanostructures' optical qualities. The mechanism is thoroughly investigated and it is found that the nanocubes themselves can act as reducing agents, promoting growth preferentially into the gap as a result of electrostatic interactions. By controlling experimental parameters such as temperature, pH, and the introduction of capping agents, a balance between nanocube epitaxy and shape retention is achieved. Finally, by applying this procedure to nanoparticle assembled in predefined meta-atoms, the feasibility of creating intricate silver nanostructures, that are monocrystalline as verified by transmission electron microscopy (TEM), is demonstrated. This advancement paves the way for bottom-up fabrication of optical metasurfaces that can be swiftly integrated indevices.

Oblique effects with multisegment spectacle lenses: 1. Images of a point object.

Multisegment (MS) spectacles are intended to slow myopia progression by modifying images falling on the peripheral retina. Some published optical treatments of these lenses assume normal incidence of light at the surfaces, but images falling on the peripheral retina are usually associated with oblique ray pencils. Here, we model representative images of point objects produced by the Hoya MiyoSmart MS spectacle lens when oblique ray pencils are used. Various imaging aspects of the MS lens alone and in combination with a suitable accommodating eye model for a 4D myope were evaluated using the Optical Design program Ansys Zemax OpticStudio. Configurations studied included object points at vergences of zero and -4 D, with the objects being either on the lens axis or at a field angle of about 30°. The effect on foveal vision of rotating the axis of the eye with respect to that of the lens was also considered. Images of point objects were described in terms of spot diagrams and fast Fourier transform point-spread functions. Symmetry and overall optical quality of images decreased with the obliquity of the ray pencils, due to the increased off-axis aberrations of the lens and the eye. Images of near object points were strongly affected by the level of accommodation: optimal retinal image quality occurred when accommodation brought the carrier lens focus close to the retina, rather than that of the lenslets. Attempts to understand why MS lenses slow myopia progression need to consider the way in which through-focus retinal image quality changes with obliquity of the ray pencils across the visual field and the possible effects of ocular accommodation.

Experimental and numerical analysis of a new thermoplastic pultrusion technology of CF/PA6 rod using prepreg tapes

AbstractFiber‐reinforced thermoplastic polymer composites, as replacements for steel reinforcements, are anticipated to enhance service performance and lifespan due to their reprocessability, recyclability, high toughness, and durability. In this study, a thermoplastic pultrusion technology was developed using prepreg tapes. With this technology, carbon fiber‐reinforced polyamide 6 (CF/PA6) rods with a diameter of 6 mm were prepared successfully using CF/PA 6 prepreg tapes at three pulling speeds of 0.2, 0.5, and 0.8 m/min. The temperature field, dynamic viscosity, microscopic morphology and mechanical properties of CF/PA6 rods were tested and analyzed to study the effect of pulling speed on the surface finish quality and consolidation. The results showed that the simulated temperature field within the CF/PA6 composites well matched the practical temperature field, attributed to the application of the dynamic mesh technique. An optical surface finish quality (Sa = 0.46 μm) was achieved at a pulling speed of 0.2 m/min, due to the increased dynamic viscosity of the PA6 resin, which enhanced shear stress between the composite and the cooling die cavity. Additionally, the lowest void content (0.7%) was achieved at this pulling speed. Possible reason was the fact that the increased pulling speed decreased the heating time of CF/PA6 composites, resulting in the presence of unconsolidated tapes in the inner region. The flexural strength, flexural modulus and interlaminar shear strength of CF/PA6 rods prepared at 0.5 and 0.8 m/min decreased by 20.7%, 5.8%, and 6.6%, as well as 28.6%, 15.2%, and 23.1%, respectively.Highlights A thermoplastic pultrusion technology was proposed by using prepreg tapes. The temperature field was accurately predicted using dynamic mesh technique. The dynamic viscosity was a major factor affecting the surface quality. Deconsolidation of the prepreg tapes caused an increase in void content.

Research on the Quality Improvement of the Segmented Interferometric Array Integrated Optical Imaging Based on Hierarchical Non-Uniform Sampling Lens Array

As a typical representative of advanced remote sensing imaging technology, the segmented interferometric array integrated optical imaging system has problems such as poor contrast, insufficient medium and low-frequency information, and low resolution in its imaging quality. In this paper, based on the multi-dimensional light field conversion model of the integrated optical imaging quality of the full-link segmented interferometric array, the spatial distribution of the multi-baseline lens array is researched. The design of the hierarchical non-uniform sampling lens array, which is symmetrical in spatial distribution, is proposed. Combined with the actual production and processing, the influence of the fill factor of the lens array on the imaging quality is analyzed, and the tolerance error for the fill factor of the lens array is 10%. The research results can provide a theoretical basis for the optimal design and fabrication of the segmented interferometric array integrated optical imaging system.

Optical quality of the cornea one year after Cretan protocol plus in eyes with keratoconus

ABSTRACT Clinical relevance Cretan protocol plus is a novel technique that combines corneal cross-linking with refractive procedures in patients with keratoconus. Visual improvement is not only limited to visual acuity, the optical quality may also be enhanced by the Cretan protocol. Background To evaluate the higher-order aberrations (HOAs) and optical quality of the cornea 1 year after the Cretan protocol plus in keratoconus patients. Methods The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction spherical equivalent (MRSE), and topographical analysis of the cornea were assessed. The corneal optical quality parameters, including total HOA (Z3–8), vertical coma (Z3 −1), horizontal coma (Z3 1), vertical trefoil (Z3 −3), oblique trefoil (Z3 3), and spherical aberration (Z4 0), modulation transfer function (MTF) and Strehl ratio of point spread function (PSF) over the 4 mm diameter pupil were recorded via Sirius dual-scanning corneal tomography. All data were analysed preoperatively, 1 month, 6 months, and 1 year postoperatively. Results Twenty eyes of 16 keratoconus patients with 1 year of follow-up were included. After the Cretan protocol plus, the mean UDVA, CDVA, MRSE, corneal astigmatism, simulated keratometry-1, simulated keratometry-2, and maximum keratometry (Kmax) improved significantly throughout the follow-up visits (p < 0.001). Total HOA, vertical coma, and spherical aberration were significantly reduced at 1 year compared with the preoperative values (p < 0.05). Vertical coma was decreased from preoperative to all postoperative time points (p = 0.009). Regarding optical quality, MTF 5 and MTF 10 at both the vertical and horizontal meridians were significantly increased 1 year after the Cretan protocol plus compared to preoperatively (p < 0.05). Significant improvements in the PSF occurred at all postoperative time points (p < 0.001). Conclusions The Cretan protocol plus is more efficient in improving optical quality while reducing corneal aberrations in keratoconus patients. Vertical coma and PSF could be objective indicators of optical performance after this procedure.

The influence of soft contact lenses on the corneal nerve growth factor and optical quality

Objective: To explore the correlation between the nerve growth factor (NGF) in the corneal stroma and the corneal optical quality in high myopia patients wearing soft contact lenses (SCLs) for a long time before small incision lenticule extraction (SMILE). Methods: A retrospective cohort study was conducted. Sixty high myopia patients (120 eyes) who underwent SMILE in Shanghai Tenth People's Hospital from December 2020 to October 2022 were included, with an age of (30.75±4.37) years, including 26 males and 34 females. According to the duration of wearing SCLs before surgery, they were divided into three groups: group A (wearing time>10 years), group B (wearing time≤10 years), and group C (without wearing lenses). General examinations were carried out to collect medical histories and parameters, such as uncorrected visual acuity, intraocular pressure, and axial length of the eye. The Pentacam corneal topography system was used to measure corneal higher-order aberrations, including total higher-order aberrations and various coma aberrations, and to obtain the optical density of different parts and layers of the cornea. A part of the corneal stromal lenticule was used for immunofluorescence detection, and another part was used to detect the NGF level. Results: The expression level of NGF in the corneal stromal lenticules showed an upward trend with the prolongation of the wearing time of SCLs (P<0.05). The total higher-order aberration in group A was (0.39±0.10) μm, and the horizontal coma aberration was (0.17±0.12) μm, both higher than those in group C [(0.33±0.07) μm and (0.09±0.08) μm]. The full-thickness optical density of the central 6-mm annular region of the cornea in group A (13.64±2.08) and that of the central 2-mm circular region of the cornea in group B (13.58±1.28) were both higher than that in group C (12.74±0.85) (all P<0.05). The NGF level in the corneal stromal lenticules in group A was positively correlated with the optical density of the anterior layer and the full-thickness layer within the central 6-mm circular region of the cornea (both P<0.05). In group B, the NGF level in the corneal stromal lenticules was positively correlated with the optical density of the middle layer and the posterior layer within the central 6-mm circular region of the cornea, and also positively correlated with the optical density of the middle layer and the posterior layer of the 2-mm circular region (all P<0.05). The NGF level in the corneal stromal lenticules in group C was also positively correlated with the optical density of the middle layer and the posterior layer of the 0-to 6-mm annular region of the cornea (all P<0.05). Conclusion: In high myopia patients who have worn SCLs for a long time, the expression of NGF in the corneal stromal lenticules increases, the corneal optical quality decreases, and the NGF level is closely related to the corneal optical density.

Robust blue emission from thulium oxide-doped borotellurite glass: evaluation of spectroscopic behaviors

ABSTRACT Thulium oxide (Tm2O3)-doped sodium-telluro-sulphur-borate glasses with distinct spectroscopic attributes became promising for solid-state lasers and blue LED construction. Thus, these glasses with various Tm3+ contents were prepared by melt-quenching approach and characterised to determine the influence of changing dopant concentration on their optical behaviours. Furthermore, the experimental results were complemented with the theoretical Judd – Ofelt (JO) model evaluation. The optical quality factor and JO intensity parameters including Ω 2 , Ω 4 and Ω 6 were correspondingly ranged from (1.104–3.178), (3.046–5.409), (0.886–2.186), and (0.688–0.997) × 0 − 20 cm2. Photoluminescence spectra under 358 nm excitation revealed five intense emission peaks at 452, 476, 513, 652 and 668nm due to electronic transitions in Tm3+. The CIE chromaticity plot unveiled the colour coordinates within the blue region having the highest colour purity (97.01%) at (0.152, 0.033) that closely matched with the standard EBU for blue lighting, indicating the practical application potential of the proposed glass composition.

High-quality phase-only Fourier hologram generation with camera-in-the-loop

In this paper, we propose an optimization method for Fourier holograms that enables high-quality optical reconstruction of phase-only Fourier holograms. We define the amplitude of the input image for Fourier hologram calculation as an optimization plane within a camera-in-the-loop (CITL) framework to generate phase-only holograms with superior optical reconstruction quality. Unlike traditional CITL methods that optimize phase holograms, our proposed method optimizes input amplitudes that exhibit a high correlation with the original input images in the Fourier hologram. Leveraging this correlation, we introduce a neural network model for phase-only Fourier hologram, PoFNet, to infer the optimized input amplitudes from the original images, thereby addressing the time-consuming nature of the traditional CITL algorithm, which is hindered by repetitive calculations. During the training process, PoFNet employs our proposed CITL to account for non-ideal forward propagation, i.e., optical propagation. Optical experiments demonstrate that both our proposed CITL method and PoFNet effectively reduce noise in the Fourier optical path.

Efficient recognition of composite vortex beams with multi-mode in atmospheric turbulence based on convolutional neural network

In recent years, vortex beams have been widely used in optical communication because of their characteristics. However, it is noted that the information encoding of a single-mode vortex beam is limited by the size of physical device. To resolve the information limitation problem associated with single-mode vortex beams, an idea of multi-beam switching superposition can be applied to composite vortex beam with multi-mode. Here, a convolutional neural network is combined to simulate and recognize the specific modes of composite vortex beams. Moreover, taking into account the atmospheric turbulence environment, the recognition effect is numerically simulated under three different levels of turbulence intensity. Finally, a compensation scheme is proposed for strong turbulence, whose recognition rate is upto 97.82% in harsh environments. This finding attests to the efficiency of our proposed technique. These results are expected to generate novel concepts for enhancing optical communication capacity and quality in the future.

A Hidden Chemical Assembly Mechanism: Reconstruction-by-Reconstruction Cycle Growth in HKUST-1 MOF Layer Synthesis.

Thin metal-organic framework films grown in a layer-by-layer manner have been the subject of growing interest. Herein we investigate one of the most popular frameworks, the type HKUST-1. Firstly, we show a special synthesis procedure resulting in quick but optically perfect growth. This enables the synthesis of films of excellent optical quality within a short timeframe. Secondly and most importantly, we address the known, but not fully understood observation that the expected growth rate of one monolayer per cycle is strongly exceeded, e. g. by a factor of 4. This is an often-ignored inconsistency in the literature. We offer a growth model using a reconstruction process in every cycle leading to a deterministic reconstruction-by-reconstruction (RbR) cycle growth with a 4-times higher growth rate. It represents an up-to-now hidden chemical assembly mechanism.