Journal of The Optical Society of America A-optics Image Science and Vision最新文献

Peripheral vision plays a crucial role in extended reality by supporting immersion, navigation, and spatial awareness beyond the central field of view. However, it also presents perceptual differences compared to central vision, such as reduced visual acuity. One of the most significant challenges is visual crowding, where the presence of nearby elements disrupts the recognition of a peripheral target. While extensively studied in visual neuroscience, the practical implications of crowding for immersive image processing remain largely unexplored. This study investigates how crowding affects the perception of blur in natural textures within an extended reality environment. Participants were asked to detect blur in peripheral texture patches, presented in isolation or surrounded by similar textures. The results confirm that the presence of surrounding textures impairs blur sensitivity, with the strength of this effect depending on the properties of the textures. Specifically, crowding is more pronounced when the target and its surroundings are visually similar or when the central texture can be easily inferred from the surrounding content. By understanding how crowding happens in realistic scenes, this work opens perspectives for perceptually guided rendering and compression strategies in extended reality, where imperceptible degradations can be introduced without compromising visual quality.

We present a systematic method for the creation of tunable three-dimensional dark spots in the focal volume by focusing high-order radially polarized transverse modes (R-TEM). By applying the binary phase mask of opposite phases, it works as a polarization filter and tailors the focal field structure by suppressing the longitudinal components. The dark focal spots of variable sizes are created for different high-order modes, such as R-TEM₀₁, R-TEM₁₁, R-TEM₂₁, R-TEM₀₂, R-TEM₁₂, and R-TEM₂₂, by focusing through the optical system over a range of low numerical apertures (NAs). Our approach extends the functionality of binary phase modulation to achieve localized 3D intensity nulls with high spatial precision. These tunable dark focus structures hold significant potential for advanced applications, including optical trapping of low-index particles, high-resolution imaging with reduced background illumination, and structured light-matter interaction.

Dynamic speckle phenomena, arising from coherent light scattering on moving diffuse surfaces, are widely used for motion analysis in fields such as biomedical imaging and industrial inspection. However, the classification of dynamic speckle regimes remains challenging, particularly in understanding their distinct temporal and spatial behaviors across various velocity ranges. In this study, we introduce a comprehensive framework for categorizing speckle dynamics into three regimes: frozen, intermediate, and fully decorrelated. Each exhibits distinct temporal decorrelation properties, with direct consequences for motion quantification. To validate this framework, we designed an experimental setup comprising a coherent laser source, a controlled rotational diffuser as the moving scattering surface, and a high-resolution imaging system. This configuration enables precise control of speckle motion and systematic sampling of a wide velocity range. The experimental results reveal consistent and reproducible transitions between the three regimes, in strong agreement with the predicted contrast-velocity relationships. Our findings underscore the practical significance of this classification. In particular, they demonstrate that system performance depends critically on the regime in which measurements are made. Accurate velocity estimation requires adapting the acquisition strategy to the specific characteristics of each regime, including frame rate and exposure time. The intermediate regime, where contrast varies only weakly with velocity, should be avoided in system design due to its poor sensitivity. In addition to clarifying speckle dynamics, this framework enables the optimization of imaging system parameters by ensuring that measurements are performed in regimes where contrast is most sensitive to motion.

We present and compare two methods for evaluating the far-field mean intensity of Gaussian beam propagation through the atmosphere. Using simulation data encompassing multiple scenarios, including turbulence and thermal blooming, we constructed the dual path attention transformer (DPAT) model and compared it with an established scaling law model. We evaluated these models in terms of accuracy, influence of sample size, generalization capability, and computation time, in conditions of turbulence-only and combined effects of turbulence and thermal blooming. The results demonstrate that the DPAT model maintains consistent accuracy in both conditions, with its precision exhibiting enhancement with increased training sample size. Furthermore, the computation time of the scaling law model is the shortest, whereas the DPAT model demonstrates superior generalization capability.

The two-step indirect method for evaluating the beam shape coefficients (BSCs) of the electromagnetic field of a circular non-vortex Gaussian beam was recently proposed to simplify the analytical work in formulating the BSCs and to speed up the relevant numerical calculation. In this work, the indirect method is extended to a family of circular vortex beams carrying topological charges, which requires an additional recurrence for calculating the translation coefficients. Numerical results of the hollow vortex Gauss beam verify that the proposed method can avoid tedious analytical derivation and improve the efficiency of numerical calculation.

Organic light-emitting diode (OLED) displays have been widely used in smartphones in recent years. Manufacturers use the stroboscopic visibility measure (SVM) to characterize and compare the performance of OLED displays using the pulse-width modulation (PWM) dimming method in producing perceivable flicker, although the SVM was developed for lighting products. This study investigated how the dimming frequency and display luminance of an OLED smartphone display affected the stroboscopic effect by presenting an oscillating arm in front of the display. The results showed that the stroboscopic effect was visible when the dimming frequency was 480 and 960 Hz with the display luminance below 40cd/m², and when the dimming frequency was 1440 Hz, with the display luminance at 5cd/m², the threshold of the duty cycle was around 50%. When the dimming frequency was 1920 or 2160 Hz, the stroboscopic effect was invisible. The results also suggested that for OLED displays, the SVM may still be used, but an SVM of 1.5 to 2 can be used as a conservative threshold instead under the experimental conditions.

The transformation of Gaussian beams into structured intensity profiles, such as flat-top and ring-shaped distributions, is a longstanding goal in beam shaping. Conventional methods using spatial light modulators, digital micromirror devices, or interferometry are effective but often bulky and expensive. This paper explores a simpler, low-cost alternative by shaping Gaussian beams through soft and hard truncation. We examine this approach in both Cartesian and cylindrical coordinate systems, covering beam types such as the cosine beam, cosine-Gaussian beam, elegant Hermite-Gaussian beam, truncated cosine beam, and truncated Hermite-Gaussian Beam, along with their cylindrical counterparts: the Bessel beam, Bessel-Gaussian beam, elegant Laguerre-Gaussian beam, truncated Bessel beam, and truncated Laguerre-Gaussian beam. Using mathematical asymptotics and Fourier optics, we provide theoretical insight into how truncation and spatial modulation shape the far-field beam profiles. This framework not only explains the formation of flat-top and ring-shaped beams but also supports the development of compact, passive beam-shaping systems.

The propagation characteristics of high-energy lasers in slant-path non-Kolmogorov maritime atmospheric turbulence are complicated due to the competition between turbulence and thermal blooming effects. The exploration of laser beams with enhanced turbulence and thermal blooming resistance has emerged as a critical issue for high-energy laser engineering applications. Based on this, by means of a four-dimensional simulation model combining the turbulence and the thermal blooming, the propagation characteristics of a perfect vortex beam array in a slant-path non-Kolmogorov maritime atmosphere have been analyzed in detail. The influence of the parameters, such as the topological charges, widths of the annulus, beam widths, altitudes, and zenith angles, has been analyzed. In addition, the comparison of the propagation characteristics of the Gaussian beam array, vortex beam array, and perfect vortex beam array was carried out. Results indicate that, with appropriate selection of the parameters, the perfect vortex beam array exhibits better performance over the vortex beam array and the Gaussian beam array in suppressing the combined effects of atmospheric turbulence and thermal blooming. We hope these results may provide useful guidance for high-energy laser applications in slant-path non-Kolmogorov maritime atmospheric turbulence.

Variations in illumination conditions critically degrade color fidelity in digital images, thereby compromising the accuracy of downstream computer vision tasks. Building upon these historical principles, this paper proposes a self-attention autoencoding feature support vector regression algorithm. The method extracts probability distributions in the luminance-red-green color space as primitive features, reconstructs them through a self-attention augmented autoencoder, and deploys support vector regression for illumination estimation. Experimental validation demonstrates superior robustness against noise and illumination diversity compared to feature-based alternatives. On the linear GreyBall SFU dataset, our method achieves an average 64.4% reduction across six key error metrics relative to the minimum values from all eight comparative methods. On the Cube++ dataset, it yields an average 44.9% reduction across six error metrics relative to the minimum values from all six comparative methods.

We conduct numerical simulations of the transmission of controllable cross-phase beams in strongly nonlocal nonlinear media (SNNM), investigate the underlying physical mechanisms of mode conversion in various beam structures, and analyze the impact of cross-phase on the transmission characteristics of multibeam coupling. It is observed that nonuniformity in energy distribution during single-beam transmission drives the redistribution of transverse energy, resulting in the dynamic conversion of the beam mode. This beam mode conversion process exhibits notable stability. The initial configuration of the beam array is determined by the off-axis parameters of each constituent beam element. By adjusting the cross-phase and chirp parameters, the same array can exhibit a variety of periodic propagation behaviors. The evolution of orbital angular momentum (OAM) density is periodic, with its spatial distribution exhibiting axial symmetry. The results presented in this paper provide theoretical insights into the fields of optical communication and particle manipulation.