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

JOSA A Editor-in-Chief Olga Korotkova, Deputy Editor Markus Testorf, and the members of the 2024 Emerging Researcher Best Paper Prize Committee announce the recipient of the 2024 prize for the best paper published by an emerging researcher in the Journal.

The physical characteristics of obtainable diffraction-limited light sheets (thickness ∼µm) are keys to the determination of achievable imaging performance of light sheet fluorescence microscopy (LSFM) imaging modality. The beam shape and its characteristics are solely defined by the optical characteristics of the illumination arm, i.e., by the optical characteristics of the optical components in the illumination arm and the beam profile of the incident optical beam. Typically, the illumination arm in LSFM is constituted by a cylindrical lens and a diffraction-limited spherical (converging) lens. The existing theoretical or analytical models are limited only to (i) an optical illumination arm with a single cylindrical lens (without a spherical lens) and (ii) a planar incident optical beam instead of the practically more relevant beam, for example, Gaussian. We report a complete and unique angular-spectrum-based theoretical formulation of beam-shaping, i.e., combining cylindrical and spherical lenses, for LSFM that holds true for Gaussian as well as planar beams. Validation studies, both experiments and numerical simulation, were conducted. Results demonstrate that our model enables us to estimate the performance indices with better accuracy [spatial (axial) resolution (∼2.18%), imaging depth or admissible sample size/thickness (∼1.30%), field of views (FOVs) (∼39.15%), signal contrast ratio (CR) (∼8.65%), and SNR (∼2.47%)]. This report will be of significant impact on imaging (in general) and LSFM (specifically) and its technological advances.

It appears that the knife-edge diffraction phenomenon has been well-studied over the past 200 years, but a recent study reported a new feature in its diffraction pattern: the concaveness of diffraction fringes and its reversal of direction from near field to far field. This study presents comprehensive experimental results of diffraction from various types of knife edges. The results show the concaveness of both reflective and passing-through diffraction. Using the approach of diffuse reflection from infinitesimal structure, this paper explains both qualitatively and quantitatively the knife-edge diffraction patterns.

The partially reflected and partially transmitted light by a thin film structure or a surface or interface will have a phase difference which will be half π if the structure is non-absorbing. This paper will conduct experiments to demonstrate a method to measure this phase difference between the transmitted and reflected light in beam splitting by measuring the two complementary output signals of Fourier-transform Mach-Zehnder interferometers. It will use a dielectric coated cube beam splitter and an uncoated glass surface as a beam splitter, respectively, and it will find that there will be a nontrivial phase difference in the case of the cube beam splitter. A phase difference of 0.5180 (2π) was observed using a cube beam splitter while a phase difference of 0.5005 (2π) was observed using a glass slab. Theoretical analysis was derived to support the experimental findings. This paper posits that this phenomenon can potentially be used as a novel way to measure the properties of thin film materials or interfaces.

We analyze the relation between the space-frequency and space-time coherence properties of scalar optical fields when deterministic and/or random linear transformations are performed in the frequency domain. Particular attention is paid to the irreversibility of the coherence properties under random operations. We introduce two time-domain order parameters, neither of which can increase under random transformations that preserve the power spectrum. We also identify different classes of spectrally completely coherent stochastic fields that the descriptors of coherence introduce. The results can be useful in the research of light propagation through random media.

We consider the question of monitoring polarization purity, that is, measuring deviations from orthogonality δ_τ and δ_ϵ of an ostensibly orthogonal polarization basis with a reference channel of ellipticity ϵ and tilt τ. A simple result was recently derived for a phase-sensitive receiver observing unpolarized radiation [IEEE Trans. Geosci. Remote Sens.62, 2003610 (2024)10.1109/TGRS.2024.3380531]: with ρ⁽¹⁾ denoting the Pearson complex correlation coefficient between channel complex fields, it states that ∓cos⁡(2ϵ)δ_τ±iδ_ϵ≈ρ⁽¹⁾ when δ_τ,ϵ≪1. However, phase-sensitive (in-phase and quadrature) data are seldom available at optical frequencies. To that end, here we generalize the result by deriving a new equation for the polarization "alignment" error: cos²(2ϵ)δτ2+δ_ϵ²≈ρ⁽²⁾, where ρ⁽²⁾ is the intensity cross-correlation coefficient. Only the measurement of the (real) intensity cross-correlation coefficient is needed when observing unpolarized light. For the special case of a linearly polarized basis, the tilt error is simply δ_τ≈ρ⁽²⁾, and for the circular basis case, with ellipticity deviation δ_ϵ from circular helicity π/4 (the reference channel of opposite helicity), δ_ϵ≈ρ⁽²⁾. These results provide simple means to gauge the quality of polarimeters and depolarizers.

The atmospheric coherence length reflects turbulence effects and is a crucial parameter for atmospheric propagation and adaptive optics. In this paper, moiré deflectometry based on double-cross gratings has, for the first time to our knowledge, been implemented to achieve the measurements of the spatial-temporal distribution of atmospheric coherence length. Initially, the theoretical relationship between phase and atmospheric coherence length is established. Subsequently, the phase information is extracted from the grid moiré fringes captured in the experiment. Based on this, the spatial-temporal distribution of atmospheric coherence length can finally be obtained. The results are in good agreement with typical values calculated by other methods, which verify their reliability and superiority. In other words, the related outcomes expand the potential of moiré deflectometry with cross gratings, which opens up new possibilities for its application in the study of atmospheric turbulence properties.

A high-efficiency method for the light curves formation using sector generalized spiral phase plates is proposed. It is possible to change not only the phase gradient value but also its direction in different sections of the curve. This provides the ability to control the orbital angular momentum and the transverse energy flow density of the formed beam.

The relativistic analysis of light reflection from a moving mirror, originally derived by Einstein, extends naturally to corner retroreflectors. This paper presents a Taylor-Fourier series expansion of Einstein's formulas and identifies a discrepancy in the second-order term of Dashchuk's analysis, as reported in Proc. IEEE57, 2148 (1969)10.1109/PROC.1969.7499. A geometric derivation of the angular reflection law is also provided, independent of Lorentz transformations. Additionally, a coordinate-free geometric construction is introduced for determining the direction of the reflected beam, given the incident beam and the velocity of the corner reflector.

A heuristic definition of caustics is simply the locus of light-intensity concentration. However, zooming into caustics reveals subtle structures; unraveling them involves employing sophisticated mathematics dealing with singularities. This paradoxical epistemic duality has made caustics a crucial concept permeating the evolution of optics itself since its origins. Moreover, the seemingly capricious caustic shapes found in nature-the rainbow being the most inspiring theme-have stimulated some of the sharpest minds in science throughout the ages. The ever-deepening understanding of the structures of caustics has co-evolved with various branches of mathematics, such as geometry and divergent series. I present a historical review of this profound co-evolution from ancient times to the 80s of the 20th century.