Forward Light Scatter Research Articles

Depolarized Forward Light Scattering for Subnanometer Precision in Biomolecular Layer Analysis on Gold Nanorods.

Functional gold nanoparticles have emerged as a cornerstone in targeted drug delivery, imaging, and biosensing. Their stability, distribution, and overall performance in biological systems are largely determined by their interactions with molecules in biological fluids as well as the biomolecular layers they acquire in complex environments. However, real-time tracking of how biomolecules attach to colloidal nanoparticles, a critical aspect for optimizing nanoparticle function, has proven to be experimentally challenging. To address this issue, we present a depolarized forward light scattering (DFLS) method that measures rotational relaxation constants. In DFLS, optically anisotropic nanoparticles are illuminated with linearly polarized light and the forward light scattering is analyzed in a cross-polarized configuration. We demonstrate the application of DFLS to characterize various functional coatings, analyze biomolecular binding kinetics to gold nanoparticles, and determine specific protein adsorption affinity constants. Our results indicate that DFLS offers a powerful approach to studying nanoparticle-biomolecule interactions in complex environments such as bodily fluids, thereby opening new pathways for advancements in nanomedicine and the optimization of nanoparticle-based drug delivery systems.

Classification of Ice Particle Shapes Using Machine Learning on Forward Light Scattering Images

Abstract Machine learning (ML) has rapidly transitioned from a niche activity to a mainstream tool for environmental research applications including atmospheric science cloud microphysics studies. Two recently developed cloud particle probes measure the light scattered in the near forward direction and save digital images of the scattering light. Scattering pattern images collected by the Particle Phase Discriminator mark 2, Karlsruhe edition (PPD-2K), and the Small Ice Detector, version 3 (SID-3) provide valuable information for particle shape and size characterization. Since different particle shapes have distinctly different light scattering characteristics, the images are ideally suited for ML. Here, results of a ML project to characterize ice particle shapes sampled by the PPD-2K in ice fog and diamond dust during a 3-yr project in Fairbanks, Alaska. About 2.15 million light-scattering pattern images were collected during 3 years of measurements with the PPD-2K. Visual Geometry Group (VGG) convolutional neural network (CNN) was trained to categorize light-scattering patterns into eight categories. Initial training images (120 each category) were selected by human visual examination of data, and the training dataset was augmented using an automated iterative method for image identification of further images which were all visually inspected by a human. Results were well correlated to similar categories identified from previously developed classification algorithms. ML identifies characteristics not included in automated analysis such as sublimation. Of the 2.15 million images analyzed, 1.3% were categorized as spherical (liquid), 43.5% were categorized as having rough surfaces, 15.3% were pristine, 16.3% were categorized as sublimating, and the remaining 23.6% did not fit into any of those categories (irregular or saturated). Significance Statement The shapes and sizes of cloud particles can be extremely important for understanding the conditions that exist in the cloud. In this study, we show that more information about cloud particle characteristics can be identified by using machine learning than by traditional means. To demonstrate this, data are analyzed from a 3-yr study of ice fog and diamond dust events in Fairbanks, Alaska. The Particle Phase Discriminator instrument collected 2.15 million light-scattering pattern images of cloud particles during ground-based measurements. Neither traditional techniques nor machine learning were able to identify all categories, but a combination of both techniques led to a more complete view of ice particle shapes.

Associations Between Visual Functions and Severity Gradings, Corneal Scatter, or Higher-Order Aberrations in Fuchs Endothelial Corneal Dystrophy.

The purpose of this study was to investigate the associations between visual function and severity grading, corneal scatter, or higher-order aberrations (HOAs) in patients with Fuchs endothelial corneal dystrophy (FECD). This observational case series study included 49 eyes of 27 patients with FECD and 10 eyes of 10 healthy individuals. We evaluated corrected distance visual acuity (CDVA) using Landolt-C and Early Treatment Diabetic Retinopathy Study charts and contrast sensitivity using the CSV-1000E chart and CSV-1000RN letter chart. We analyzed the associations between visual function and explanatory variables, including age, modified Krachmer grade, central corneal thickness (CCT), anterior segment optical coherence tomography (AS-OCT)-based grade, HOAs, intraocular straylight, and corneal densitometry. We additionally conducted receiver operating characteristic (ROC) analysis to identify the corneal densitometry thresholds for decreased visual function. There were significant associations between visual function and the modified Krachmer grade, CCT, AS-OCT-based grade, HOAs, intraocular straylight, and corneal densitometry. A modified Krachmer grade ≥ 3 was identified as a threshold for decreased visual function. Multivariate analysis showed that corneal densitometry was significantly associated with all visual function parameters, and HOAs were significantly associated with CDVA but not with contrast sensitivity. ROC analysis revealed that corneal densitometry of the posterior layer at 0 to 2mm ≥ 10 grayscale units (GSU), was identified as a threshold for decreased visual function. HOAs, forward and backward light scatter affected visual function, with backward light scatter being the most influential. In patients with FECD, modified Krachmer grade ≥ 3 and corneal densitometry ≥ 10 GSU were thresholds for visual disturbance.

Forward Light Scattering of the Vitreous Gel After Enzymatic Aging: An In Vitro Model to Study Vitreous Opacification.

Symptomatic vitreous opacifications, so-called floaters, are difficult to objectively assess majorly limiting the possibility of in vitro studies. Forward light scattering was found previously to be increased in eyes with symptomatic floaters. Using an objective setup to measure forward light scattering, we studied the effects of enzymatically digesting the components of the vitreous body on straylight to develop an in vitro model of vitreous opacifications. Fifty-seven porcine vitreous bodies were digested using hyaluronidase, collagenase, trypsin, and bromelain, as well as using a combination of hyaluronidase + collagenase and hyaluronidase + bromelain. A modified C-Quant setup was used to objectively assess forward light scattering. Depletion of hyaluronic acid majorly increased vitreous straylight (mean increase 34.4 deg2/sr; P = 0.01), whereas primarily digesting the vitreous gel with collagenase or trypsin did not significantly affect straylight. When collagenase or bromelain is applied in hyaluronic acid depleted vitreous gels, the increase in forward light scattering is reversed partially. The age-related loss of hyaluronic acid primarily drives the increase in vitreous gel straylight induced by conglomerates of collagen. This process can be reversed partially by digesting collagen. This in vitro model allows the objective quantification and statistical comparison of straylight burden caused by vitreous opacities and, thus, can serve as a first testing ground for pharmacological therapies, as demonstrated with bromelain.

Causes, impact, and reversibility of glare in patients with Fuchs endothelial corneal dystrophy: A review

Fuchs endothelial corneal dystrophy (FECD) is a degenerative, autosomal dominant disorder predominantly affecting the female population and can lead to progressive loss of vision. A primary and debilitating symptom of FECD is glare, which severely impairs visual acuity and quality of life. Glare in FECD is caused by light scatter due to structural changes in the cornea, particularly central guttae formation in the Descemet membrane. These changes result in forward and backward light scatter, leading to disability glare and reduced contrast sensitivity. These visual disturbances are particularly dangerous, contributing to a higher risk of road traffic accidents. Many intrinsic factors such as certain genetic mutations can lead to degeneration of the Descemet’s membrane. Extrinsic factors such as smoking, dietary and lifestyle factors, ultraviolet radiations, oestrogen quinones can also lead to corneal dystrophy. Addressing glare through surgical interventions, primarily Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK), has shown to improve visual clarity and reduce glare symptoms. Understanding and addressing glare in FECD is essential for improving patient outcomes. Continued research and advancements in treatment techniques are vital for enhancing the quality of life for individuals affected by this debilitating condition. This review focuses on highlighting the various aspects leading to FECD, the impact of glare on patients, and summarizes the surgical options for glare reversal in these patients.

Novel Colorimetric and Light Scatter Methods to Identify and Manage Peritoneal Dialysis-Associated Peritonitis at the Point-of-Care

IntroductionPeritoneal dialysis-related peritonitis is a common cause of transfer to haemodialysis, patient morbidity and is a risk factor for mortality. Associated patient anxiety can deter selection of PD for renal replacement therapy. Diagnosis relies on hospital laboratory tests, however this might be achieved earlier if such information was available at the point-of-care, thereby significantly improving outcomes. The presence of culturable microbes and the concentration of leukocytes in effluent both aid peritonitis diagnosis, as specified in the International Society for Peritoneal Dialysis diagnostic guidelines. Here we report the development of two new methods providing such information in simple point-of-care tests. MethodsOne approach uses a tetrazolium-based chemical reporting system, primarily focused on detecting bacterial contamination and associated vancomycin-sensitivity. The second approach uses a novel forward light-scatter device (QuickCheck) to provide an instant quantitative cell count directly from PD patient effluent. ResultsThe tetrazolium approach detected and correctly distinguished lab isolates, taking 10h to provide non-quantitative results. We compared the technical performance of the light scatter leukocyte counting approach with spectrophotometry, haemocytometer counting and flow cytometry (Sysmex) using patient effluent samples. QuickCheck had high accuracy (94%) and was the most precise (coefficient of variation <4%), showing minimal bias, overall performing similarly to flow cytometry. ConclusionsThese complementary new approaches provide a simple means to obtain information to assist diagnosis at the point-of-care. The first provides antibiotic sensitivity following ten hours incubation, whereas the second optical approach (QuickCheck), provides instant accurate total leukocyte count.

Early Blood Clot Detection Using Forward Scattering Light Measurements Is Not Superior to Delta Pressure Measurements.

The occurrence of thrombus formation within an extracorporeal membrane oxygenator is a common complication during extracorporeal membrane oxygenation therapy and can rapidly result in a life-threatening situation due to arterial thromboembolism, causing stroke, pulmonary embolism, and limb ischemia in the patient. The standard clinical practice is to monitor the pressure at the inlet and outlet of oxygenators, indicating fulminant, obstructive clot formation indicated by an increasing pressure difference (ΔP). However, smaller blood clots at early stages are not detectable. Therefore, there is an unmet need for sensors that can detect blood clots at an early stage to minimize the associated thromboembolic risks for patients. This study aimed to evaluate if forward scattered light (FSL) measurements can be used for early blood clot detection and if it is superior to the current clinical gold standard (pressure measurements). A miniaturized in vitro test circuit, including a custom-made test chamber, was used. Heparinized human whole blood was circulated through the test circuit until clot formation occurred. Four LEDs and four photodiodes were placed along the sidewall of the test chamber in different positions for FSL measurements. The pressure monitor was connected to the inlet and the outlet to detect changes in ΔP across the test chamber. Despite several modifications in the LED positions on the test chamber, the FSL measurements could not reliably detect a blood clot within the in vitro test circuit, although the pressure measurements used as the current clinical gold standard detected fulminant clot formation in 11 independent experiments.

Forward Light Scattering of First to Third Generation Vitreous Body Replacement Hydrogels after Surgical Application Compared to Conventional Silicone Oils and Vitreous Body.

To treat certain vitreoretinal diseases, the vitreous body, a hydrogel composed of mostly collagen and hyaluronic acid, must be removed. After vitrectomy surgery, the vitreous cavity is filled with an endotamponade. Previously, pre-clinical hydrogel-based vitreous body substitutes either made from uncrosslinked monomers (1st generation), preformed crosslinked polymers (2nd generation), or in situ gelating polymers (3rd generation) have been developed. Forward light scattering is a measure of Stray light induced by optical media, when increased, causing visual disturbance and glare. During pinhole surgery, the hydrogels are injected into the vitreous cavity through a small 23G-cannula. The aim of this study was to assess if and to what extent forward light scattering is induced by vitreous body replacement hydrogels and if Stray light differs between different generations of vitreous body hydrogel replacements due to the different gelation mechanisms and fragmentation during injection. A modified C-Quant setup was used to objectively determine forward light scattering. In this study, we found that the 1st and 3rd generation vitreous body replacements show very low stray light levels even after injection (2.8 +/- 0.4 deg2/sr and 0.2 +/- 0.2 deg2/sr, respectively) as gel fragmentation and generation of interfaces is circumvented. The 2nd generation preformed hydrogels showed a permanent increase in stray light after injection that will most likely lead to symptoms such as glare when used in patients (11.9 +/- 0.9 deg2/sr). Stray light of the 2nd generation hydrogels was 3- and 2-fold increased compared to juvenile and aged vitreous bodies, respectively. In conclusion, this significant downside in the forward light scattering of the 2nd generation hydrogels should be kept in mind when developing vitreous body replacement strategies, as any source of stray light should be minimized in patients with retinal comorbidities.

Prediction of the bacterial shape in urinary tract infections with the Sysmex UF-1000i analyser: technical note.

The aim of our study was to explore the utility of the Sysmex UF-1000i analyzer as a rapid screening tool for urinary tract infections (UTI) and its ability to predict bacterial shape in order to help physicians choose the appropriate empiric treatment. This is a retrospective study, including 1023 urine cytobacteriological examinations. Urines were processed according to the recommendations of the medical microbiology reference system (REMIC). Using the Sysmex Uf-1000i analyzer, the authors evaluated bacteria forward scatter (B_FSC) and fluorescent light scatter (B_FLH) in a preliminary discrimination step for UTI caused by bacilli or cocci bacteria. The authors got 1023 positive samples. Comparing baccili and cocci bacteria, the authors observed a statistically significant difference for B_FSC but not for B_FLH. The values of B_FLH are very close for the four categories of microorganisms compared (bacilli, cocci, bacilli-cocci association, and yeasts). For these same categories, tests show different values for the B_FSC. A separate analysis of the B_FSC values for bacilli shows that their distribution is relatively homogeneous and exhibits a peak between 20 and 30ch. Dimensional parameters of bacteria generated by UF-1000i could be a rapid and useful tool for predicting the bacterial shape causing UTI.

Systematic Multiepoch Monitoring of LkCa 15: Dynamic Dust Structures on Solar System Scales

We present the highest-angular-resolution infrared monitoring of LkCa 15, a young solar analog hosting a transition disk. This system has been the subject of a number of direct-imaging studies from the millimeter through the optical, which have revealed multiple protoplanetary disk rings as well as three orbiting protoplanet candidates detected in infrared continuum emission (one of which was simultaneously seen at Hα). We use high-angular-resolution infrared imaging from 2014 to 2020 to systematically monitor these infrared signals and determine their physical origin. We find that three self-luminous protoplanets cannot explain the positional evolution of the infrared sources since the longer time baseline images lack the coherent orbital motion that would be expected for companions. However, the data still strongly prefer a time-variable morphology that cannot be reproduced by static scattered-light disk models. The multiepoch observations suggest the presence of complex and dynamic substructures moving through the forward-scattering side of the disk at ∼20 au or quickly varying shadowing by closer-in material. We explore whether the previous Hα detection of one candidate would be inconsistent with this scenario and in the process develop an analytical signal-to-noise penalty for Hα excesses detected near forward-scattered light. Under these new noise considerations, the Hα detection is not strongly inconsistent with forward scattering, making the dynamic LkCa 15 disk a natural explanation for both the infrared and Hα data.

Comparison of bacterial carbon production estimates from dilution and 3H‐leucine methods across a strong gradient in ocean productivity

AbstractThe uptake of 3H‐labeled leucine into proteins, a widely used method for estimating bacterial carbon production (BCP), is suggested to underestimate or overestimate bacterial growth in the open ocean by a factor of 40 uncertainty. Meanwhile, an alternative BCP approach, by the dilution method, has untested concerns about potential overestimation of bacterial growth from dissolved substrates released by filtration. We compared BCPDil and BCPLeu estimates from three cruises across a broad trophic gradient, from offshore oligotrophy to coastal upwelling, in the California Current Ecosystem. Our initial analyses based on midday microscopical estimates of bacterial size and a priori assumptions of conversions relationships revealed a mean two‐fold difference in BCP estimates (BCPDil higher), but no systematic bias between low and high productivity stations. BCPDil and BCPLeu both demonstrated strong relationships with bacteria cell abundance. Reanalysis of results, involving a different cell carbon‐biovolume relationship and informed by forward angle light scatter from flow cytometry as a relative cell size index, demonstrated that BCPDil and BCPLeu are fully compatible, with a 1 : 1 fit for bacteria of 5 fg C cell−1. Based on these results and considering different strengths of the methods, the combined use of 3H‐labeled leucine and dilution techniques provide strong mutually supportive constraints on bacterial biomass and production.

A Novel Optical Instrument for Measuring Mass Concentration and Particle Size in Real Time.

Particle mass and particulate size are two important parameters used to characterize the aerosol. Currently, there are a few methods for measuring particle mass concentration and particle size. However, the existing methods have their own shortcomings. In this article, we describe a novel laser scattering instrument that measures mass concentration and particle size in real time over a wide concentration range. This instrument combines laser scattering and time-of-flight aerodynamics in one optical device. There are two innovations in this paper: (1) Two APD detectors are used to receive scattered light. One receives forward-scattered light and the other receives side-scattered light. The advantage is that the sensitivity of the detector is increased greatly, and the ratio of forward and side scattering is used to further obtain the size and shape information of the particles. (2) In order to measure the high concentrations of aerosol, a high-speed ADC and FPGA is combined to achieve an anti-overlap algorithm objective. It has been verified by experiments that the anti-overlapping algorithm can effectively improve the applicability of the aerodynamic particle size spectrometer under high concentration conditions.

Frequency tunable superflash based on an electromagnetically induced transparency (EIT).

We present a new controllable superflash, a maximum transient peak at the falling edge of a square pulse, using a three-level electromagnetically induced transparency (EIT). The superflash in a two-level system occurs at a certain value of the detuning of the probe laser (Δpeak) when the optical depth (OD) of the medium is sufficiently large and constant. Here, we show the external tunability of the Δpeak for obtaining the maximum transient peak by introducing a three-level EIT. Owing to the EIT dispersion properties, we effectively tune the phase of the forward-scattered light (Es) by externally controlling the EIT coupling light intensities associated with the Rabi frequency (Ωc). When the incident light is turned off, the total transmitted field (Et) experiences an out-of-phase shift, producing a peak intensity that is three times higher than the input. We observe that this new class of superflash (Type II) occurs near the EIT window and exhibits inverse-linearity of the OD, which is in contrast with the characteristics of the previously reported two-level superflash (Type I). Furthermore, we find the quadratic nature of tunability in Δpeak(Ωc).The new tunability of the superflash by the Rabi frequency may facilitate more rapid and effective control of the superflash compared to a passive optical medium.

Diagnostic Characteristics of Urinary Red Blood Cell Distribution Incorporated in UF-5000 for Differentiation of Glomerular and Non-Glomerular Hematuria.

BackgroundAutomated urine sediment analysis has been developed to address the limitations of microscopic examination of dysmorphic red blood cells (RBCs). We evaluated the urinary RBC distribution (URD) parameter of a recently launched automated urinary flow cytometry analyzer, UF-5000 (Sysmex, Kobe, Japan), to differentiate glomerular hematuria (GH) from non-GH (NGH).MethodsSamples submitted for urine sediment analysis from patients with hematuria (>20 RBCs/μL) were divided into derivation (N=156; 101 GH, 55 NGH) and validation cohorts (N=107; 60 GH, 47 NGH). The clinical diagnosis of GH or NGH was established based on clinical data review. Differences in UF-5000 parameters (URD, small RBC, lysed RBC, RBC-P70FSC, RBC-SF-FSC-W, mean forward-scattered light, and mean side-scattered light) between GH and NGH, and areas under the ROC curves (AUC) were analyzed in the derivation cohort. The derived ideal cut-off value was evaluated in the validation cohort. We applied the Kitasato criteria to compare the diagnostic performance.ResultsURD (%), differed significantly between GH and NGH (P<0.001) in the two cohorts. The AUC of URD was 0.814 and 0.806 in the derivation and validation cohorts, respectively. Using a cut-off of >20.1%, the sensitivity was 99.0%/89.4% and the specificity was 50.9%/63.3% in the derivation/validation cohort. When the Kitasato criteria were applied, the sensitivity and specificity were 80.2% and 52.7%, respectively.ConclusionsURD is a rapid, objective, and quantitative measure that can be used to differentiate GH and NGH.

Bioymifi, a novel mimetic of TNF-related apoptosis-induced ligand (TRAIL), stimulates eryptosis.

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is a cytokine that initiates apoptosis upon binding to death receptor 5 (DR5) on cancer cells. Small molecule TRAIL mimetics have therefore been investigated as promising chemotherapeutic agents. Since anemia of chemotherapy is common, our goal is to investigate the hemolytic and eryptotic properties of novel DR5 agonist bioymifi (BMF) and identify the underlying molecular mechanisms. Whole blood (WB) was stimulated with 100μM of BMF, whereas red blood cells (RBCs) were treated with 10-100μM of BMF for 24h at 37°C. WB was analyzed for RBC, leukocyte, and platelet indices, while RBCs were examined for hemolysis by light absorbance of free hemoglobin, membrane scrambling by Annexin V-FITC, calcium by Fluo4/AM, cellular morphology by light scatter, and oxidative stress by 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) using flow cytometry. Caspase inhibitor Z-VAD-FMK, p38 inhibitor SB203580, casein kinase 1α inhibitor D4476, receptor-interacting protein 1 inhibitor necrostatin-2, reduced glutathione, or cyclooxygenase (COX) inhibitor aspirin were added accordingly. BMF exerted dose-responsive, calcium-independent hemolysis, reduced RBC hemoglobin, significantly increased Annexin V-, Fluo4-, and DCF-positive cells, along with a dual effect on forward and side light scatter. Notably, the cytotoxic potential of BMF was significantly mitigated upon pharmacological inhibition of p38. Furthermore, BMF exhibited selective toxicity to eosinophils and significantly diminished reticulocyte hemoglobin content. Altogether, these novel findings highlight the adverse outcomes of BMF exposure on RBC physiology and provide the first toxicological assessment of BMF as an antitumor agent.

The prodigiosin change on the surface of Serratia marcescens detected by flow cytometry.

The potential of flow cytometry for the study of changes in prodigiosin on the cell surface of Serratia marcescens is of academic and practical interest. This is because S. marcescens can produce prodigiosin, a secondary metabolite, with potential use as a cancer-cell inhibitor. In this study, three groups of bacterial cultures with different carbon sources were compared, and the effect of the addition of cAMP to the sucrose-based culture was studied. Both cellular morphology and DNA content were detected by flow cytometry, rendering a broad description of the bacterial behavior. It is the first use of flow cytometry to investigate the dynamics of prodigiosin on the surface of S. marcescens during growth in different media. The fluorescence intensity is related to the DNA content, the forward-scattered light is related to cell volume, and the side-scattered light is related to the surface morphology, especially the surface prodigiosin. These may contribute to the potential development of a bacterial metabolic monitoring strategy using both DNA content analysis and bacterial morphology based on flow cytometry technique.

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

Visualization of Forward Light Scatter in Opacified Intraocular Lenses and Straylight Assessment.

Background: Qualitative visualization of forward light scatter and quantitative straylight measurement of intraocular lenses (IOLs). Methods: We analyzed two calcified IOL-explants, the Euromaxx ALI313Y (Argonoptics GmbH) and the LS-312 MF30 (Oculentis BV), one IOL with artificially induced glistenings (PC-60AD, Hoya), and one control (CT Asphina 409MP, Carl Zeiss Meditec AG) free of any opacification. Analysis included light microscopy, qualitative light scatter visualization using ray propagation imaging technique, and quantitative straylight measurement using C-Quant (Oculus). Results: More light scattering effect—visible as increased light intensity outside the IOL’s main focus—was evident in all opacified IOLs than the control. The highest straylight levels were observed in the Euromaxx (289.71 deg2/sr), which showed extensive granular deposits throughout its optic, followed by the MF30 (78.58 deg2/sr), which only showed opacification in its center. The glistenings-IOL demonstrated numerous microvacuoles within the optic and had straylight levels of 22.6 deg2/sr, while the control showed the lowest straylight levels (1.7 deg2/sr). Conclusions: Ray propagation imaging technique allowed qualitative assessment of off-axis veils of light that result from increased forward light scattering. Straylight was increased in all opacified lenses compared to the clear control lens. The IOL opacifications are significant sources of glare.

Polarized Laser Backscattering of Atmospheric Cloud Distribution Based on Simulated Annealing Algorithm

Meteorological forecasting can not only reduce the losses caused by natural disasters to human society but also has a very important significance in the fields of water conservancy, aviation, and transportation. In order to improve the accuracy of meteorological forecasting, we should focus on the in-depth optical analysis of atmospheric cloud distribution. Compared with forward-scattered laser light, backscattered laser light can save more optical information. Therefore, this paper studies the backscattering of polarized laser light distributed in atmospheric clouds. In this study, a simulated annealing algorithm was used to invert the data of spaceborne lidar to obtain the depolarization degree and backscattering coefficient of atmospheric clouds and aerosols at different heights. Finally, based on the radar measurement example, the simulated annealing algorithm was used to analyze the atmospheric information of sunny, cloudy, and hazy weather in summer and winter, and the atmospheric depolarization and backscattering coefficients corresponding to different weather heights were obtained. The corresponding cloud layer type was judged. The research results prove the feasibility of the simulated annealing algorithm in the study of polarized laser backscattering in atmospheric cloud distribution. This study provides new ideas for radar data processing methods and provides a theoretical basis for further research in the field of meteorological forecasting.

Broadband Forward Light Scattering by Architectural Design of Core-Shell Silicon Particles.

A goal in the field of nanoscale optics is the fabrication of nanostructures with strong directional light scattering at visible frequencies. Here, the synthesis of Mie-resonant core-shell particles with overlapping electric and magnetic dipole resonances in the visible spectrum is demonstrated. The core consists of silicon surrounded by a lower index silicon oxynitride (SiOxNy) shell of an adjustable thickness. Optical spectroscopies coupled to Mie theory calculations give the first experimental evidence that the relative position and intensity of the magnetic and electric dipole resonances are tuned by changing the core-shell architecture. Specifically, coating a high-index particle with a low-index shell coalesces the dipoles, while maintaining a high scattering efficiency, thus generating broadband forward scattering. This synthetic strategy opens a route toward metamaterial fabrication with unprecedented control over visible light manipulation.