Optics Technology (United States)

Violet phosphorus (VP), a recently identified two-dimensional (2D) allotrope of phosphorus, exhibits a range of distinctive properties that position it as a promising material for diverse advanced applications. This review begins with a detailed examination of the synthesis strategies for VP, including bulk-phase growth, few-layer exfoliation, and the fabrication of VP quantum dots (QDs). Each method's advantages, limitations, and impact on the material's structural and electronic properties are discussed. VP's unique characteristics, such as its tunable direct bandgap, high charge carrier mobility, and anisotropic behavior, enable strong performance in optoelectronics. Applications in polarization-sensitive photodetectors, broadband photodetection, and neuromorphic vision systems are critically reviewed, emphasizing its potential for next-generation photonic devices. In the biomedical domain, VP's biodegradability, tunable optical properties, and promising electronic characteristics provide opportunities for biosensing, antibacterial treatments, and cancer therapy. Finally, VP's potential for energy storage and conversion is explored, with particular attention given to its role in photocatalytic hydrogen evolution and as an anode material in sodium-ion and lithium-ion batteries. The review provides a comprehensive analysis of VP's synthesis, properties, and multifaceted applications, while highlighting the ongoing challenges and future research directions required to fully exploit its potential.

The entoptic phenomena of Haidinger’s and Boehm’s brushes provide a noninvasive window into the structural and functional organization of the human retina. These percepts arise from polarization-dependent interactions within distinct retinal layers: radial diattenuation by macular pigments in the fovea produces Haidinger’s brushes, whereas polarization-sensitive scattering in the non-foveal retina gives rise to Boehm’s brushes. Recent advances in structured light have introduced spin–orbit beams with spatially varying polarization fields that conform to the intrinsic symmetry of retinal polarization interactions, enabling systematic expansion and enhancement of these entoptic patterns. By aligning the optical field topology with retinal architecture, such beams generalize the formation of Haidinger’s and Boehm’s brushes to complex multi-lobed geometries and provide a path toward quantitative mapping of perceptual structure across eccentricity. This review outlines the optical and biological foundations of polarization perception, summarizes recent results demonstrating its enhancement through spin–orbit structured illumination, and describes psychophysical methods for characterizing stimulus geometry, contrast sensitivity, and retinal dependence. Finally, it highlights how these techniques establish a framework for functional retinal mapping and potential future diagnostic applications capable of detecting disruptions associated with central or non-foveal retinal disease.

The importance of corneal biomechanics in ocular health and treatments is well-recognized, but reports on associated factors are inconsistent. We established normative data for corneal stiffness using Brillouin spectroscopy in a large cohort of healthy myopic corneas, exploring potential influences on Brillouin modulus (BM) measurements. Data from 1744 healthy corneas of 885 subjects (17–52 years; 422 females) were retrospectively collected, including intraocular pressure (IOP in mmHg), manifest refraction spherical equivalent (MRSE in dioptres [D]), and Pentacam measurements (central corneal thickness [CCT in µm]), K1 and K2 in D). Corneal scans were recorded on a Brillouin Optical Scanning System (BOSS®) using an automated 10-point pattern to measure Central, Mean, Minimum and Maximum BM values in gigapascals (GPa). Monocular data (primarily right eye) were used for correlations; binocular data for interocular comparisons. Parametric analyses included Pearson correlations, t-tests for sex differences, paired t-tests for interocular differences, and multivariate linear regression to isolate independent factors (e.g., age, sex, CCT, IOP) with interaction terms. Normative BM values were Central = 2.856 ± 0.053 GPa, Mean = 2.845 ± 0.038 GPa, Min = 2.819 ± 0.046 GPa, and Max = 2.885 ± 0.042 GPa. Interocular comparisons revealed statistically significant but small increases in OS compared to OD for Mean BM (0.003 GPa [95% CI: 0.001–0.005]; OD = 2.855 ± 0.038 GPa, OS = 2.858 ± 0.038 GPa; P = 0.01) and Max BM (0.004 GPa [95% CI: 0.002–0.006]; OD = 2.886 ± 0.042 GPa, OS = 2.890 ± 0.042 GPa; P = 0.003), as well as in K1 and CCT (P < 0.0001). No significant interocular differences were found in Central or Min BM (P ≥ 0.15). Central, Mean and Min BM values correlated significantly with CCT (P ≤ 0.04) but not with IOP, K1, K2, or MRSE (P ≥ 0.20); Max BM did not correlate with any of these clinical parameters (P ≥ 0.07). Males had higher BM values than females (P ≤ 0.006), with effect sizes (d = 0.21) and r = 0.09 –0.1. Regional mapping showed small overall differences in BM values between zones (P = 0.04), with slightly higher values in the Superior region. Multivariate regression confirmed independent associations: Central BM ~ age (β = 0.0008 [95% CI: 0.0001–0.0015], P = 0.04), sex (β = 0.010 [95% CI: 0.003–0.017], P = 0.008), CCT (β = 0.00015 [95% CI: 0.00005–0.00025], P = 0.003); IOP was non-significant (β = 0.0004 [95% CI: −0.0008–0.0016], P = 0.50, R² = 0.048). Age*sex interaction was non-significant (β=−0.0002, P = 0.62). While statistical significance was observed, the correlation coefficients were not large, suggesting a weak linear relationship. Non-contacting Brillouin scans in a large cohort of healthy myopic eyes established robust normative BM standards, revealing associations between corneal stiffness and age, sex, and CCT. These findings provide reference values that enhance diagnostic accuracy for conditions like keratoconus and inform biomechanical assessments in refractive surgery.

PurposeTo compare and evaluate the clinical performance and fit success of lehfilcon A and lotrafilcon B multifocal soft contact lenses (MfSCLs).Patients and MethodsThis was a prospective, randomized, double-masked, crossover, dispensing clinical study. Eligible wearers were fitted and wore study MfSCLs bilaterally (≥8 hours/day, ≥5 days/week) over 30 days. Endpoints: binocular visual acuity (VA) at distance (4 m), intermediate (80 cm), and near (40 cm) at day 30; fit rate success; eye care professional (ECP) rating, study dispensed lens power at visit 1; lens fit, and surface characteristics at dispense and day 30; safety assessments.ResultsOverall, 101 subjects were enrolled. At day 30, lehfilcon A MfSCLs were noninferior to lotrafilcon B MfSCLs for distance, intermediate, and near VA (non-inferiority margin: 0.05; 95% UCL of LSM difference 0.00, 0.02, 0.04; mean VA, lehfilcon A: −0.10 ± 0.08, −0.10 ± 0.08, and 0.01 ± 0.12; lotrafilcon B: −0.09 ± 0.07, −0.11 ± 0.08, and −0.02 ± 0.11). At visit 1, ≥99.5% of both MfSCLs achieved successful fit with 1–2 lenses/eye. Mean ECP ratings for ease of fit: lehfilcon A 9.8 ± 0.6; lotrafilcon B: 9.7 ± 0.6. About 96.0% of subjects had same sphere (D) power and 100.0% had same ADD power in both eyes for both lenses. All MfSCLs had optimal/acceptable fit. Majority of MfSCLs (>96%) had grade 0/1 front surface wettability and front/back surface deposits. No serious AEs were reported, and all biomicroscopy findings were graded 2 (mild) or lower.ConclusionLehfilcon A multifocal contact lenses combine excellent visual performance, high fit success, and a stable, comfortable wearing experience over 30 days of daily wear. With their water-gradient surface, favorable safety profile, and ease of fit, they represent a reliable and beneficial option for clinicians to consider when selecting multifocal lenses for presbyopic patients.

Background: Glaucoma is a chronic optic neuropathy traditionally managed by lowering intraocular pressure (IOP), yet progression may occur despite controlled or normal IOP, suggesting additional pathogenic pathways. Objective: To synthesize contemporary evidence describing oxidative stress–mediated mechanisms that contribute to glaucomatous damage beyond IOP alone and to summarize emerging therapeutic implications. Methods: This narrative review synthesized evidence identified through PubMed and Google Scholar searches (2021–2025), prioritizing 15 core publications for mechanistic integration and using foundational sources for background context. Results: Reactive oxygen species accumulation and impaired antioxidant defenses are consistently linked with trabecular meshwork dysfunction, extracellular matrix remodeling, and reduced aqueous outflow, which may increase IOP instability. In parallel, mitochondrial dysfunction, impaired bioenergetics, and glial-mediated neuroinflammation contribute to retinal ganglion cell vulnerability and optic nerve head degeneration, providing a plausible framework for progression in normal-tension and treatment-resistant phenotypes. Biomarker studies commonly report increased oxidative injury markers with reduced antioxidant capacity, but clinical heterogeneity limits causal inference. Conclusion: Oxidative stress and mitochondrial dysfunction plausibly contribute to glaucoma pathophysiology through pressure-dependent and pressure-independent mechanisms. Adjunctive neuroprotective strategies targeting redox balance and mitochondrial resilience are promising but require standardized biomarkers and adequately powered clinical trials.

The bandgap tunability of lead sulfide (PbS) quantum dots (QDs) positions them as a promising candidate for tandem solar cells (TSCs). However, the power conversion efficiency (PCE) of all‐PbS QDs TSCs is lagging much behind the theoretical efficiency limit due to the deficient carrier recombination capability of the interconnection layer (ICL). In this study, we fabricated all‐PbS QDs TSCs utilizing 1.40 and 0.95 eV PbS QDs for the top and bottom subcells, respectively. We developed two kinds of ICLs, 1,2‐ethanedithiol capped PbS QDs (PbS‐EDT)/Au/ZnO and PbS‐EDT/SAMs/Au/ZnO, where self‐assembled monolayers (SAMs) of 4‐(7H‐dibenzo[c,g]carbazol‐7‐yl)butylphosphonic acid (4PADCB) were the first time applied for all‐PbS QD TSCs. The SAMs bound with the PbS‐EDT hole transport layer (HTL), enhancing hole extraction from the top cell via their conjugated π‐system. Furthermore, they served to passivate traps at the HTL/Au interface, thereby reducing nonradiative recombination losses. Consequently, the top cell achieved 8.36% PCE with a semitransparent absorber layer. After the SAMs modification, it established a uniform and low‐potential surface, facilitating a uniform distribution of a thin Au recombination layer (RL). The newly developed RL enhanced hole–electron recombination. The resulting SAMs‐based TSCs achieved a certified PCE of 11.95%, more than 2% net PCE improvement over our last record data.

This chapter describes the Offner reflecting optical system design, along with a design by Reed that Offner cites as prior art in his patent, and some interesting insights and extensions into this design that came about via plate-diagram analysis.

Abstract Background Chinese classical poetry, known for its concise and evocative language, often challenges learners due to its subtle emotional expressions. Affective scaffolds, such as emotional visual and auditory cues, may enhance emotional engagement and comprehension. Aim This study investigated whether emotional visual and auditory cues facilitate learners’ emotional engagement and understanding of Chinese classical poetry. Method Two experiments were conducted. In Experiment 1, a between-subjects design with 139 high school students examined the effects of emotional visual cues (no cues, emotion label words, emotion laden words, and combined cues). In Experiment 2, a single-factor between-subjects design with 67 undergraduates explored emotional narration versus neutral narration, using eye-tracking to measure emotional engagement via pupil dilation and blink rate. Results In Experiment 1, emotion laden word cues increased negative emotional valence (d = 0.49) but did not affect comprehension. In Experiment 2, emotional narration improved poetic comprehension (d = 0.56) and motivation (d = 2.32), with greater pupil dilation (d = 2.10) and reduced blink rate (d = 0.70) indicating enhanced emotional engagement. Conclusion Emotional visual cues alone foster emotional engagement without improving comprehension, while combining them with emotional narration significantly enhances both motivation and understanding. These findings extend the cueing principle by demonstrating that emotional visual and auditory cues enhance engagement with affective content and support the emotional design hypothesis by showing that cues aligned with inherent emotional content improve comprehension and motivation in literary learning.