Exploring the Frontiers of Optical and Laser Sciences
Array beam-driven computational imaging through thin scattering layer
Imaging through scattering remains a fundamental challenge in optical systems, with applications in atmospheric and astronomical imaging. We present Array Beam-Driven Computational Imaging through Thin Scattering Layer (ABD-CI-TSL), an experimental method using temporally coherent and spatially incoherent array beams to image through thin scattering layers. Object information is encoded onto the array beam, propagated through the scatterer, and recovered via deconvolution of the recorded point spread function. The method is evaluated across varying scattering conditions and axial locations. Results demonstrate that array beams preserve object spatial features under scattering, though reconstruction fidelity degrades with increasing scattering strength, highlighting ABD-CI-TSL's potential for scattering media applications.
07-08-2026 Read MoreRoadmap on singular optics and its applications
This roadmap synthesizes emerging applications of singular optics across multiple platforms, offering a concise overview of current developments and highlighting key physical concepts, new architectures, and transformative technologies that bridge subfields. In addition to reflecting the insights of leading contributors to these research directions, it also surveys selected recent advances, providing a concise overview of current trends and a foundation for shaping the future of singular optics and its applications.
08-04-2026 Read MoreDevelopment of diffractive optical elements for generating uniform-intensity laser beams with shape-invariant features
The work focused on developing the single beam-shaping diffractive optical element (DOE) that transforms the Gaussian input laser beam into a uniform-intensity output laser beam whose intensity profile or output beam shape remains invariant to the distance of 10 mm in free space is a significant advancement achieved in the present invention. Numerical calculations, the steps in fabricating the DOE phase mask, and experimental results obtained from the fabricated DOE were analysed and discussed.
20-03-2026 Read MoreGenerating nondiffracting bottle Beams with a flat multilevel diffractive lens
We introduce a novel method for generating a high-quality, sharply defined, nondiffracting optical bottle beam by focusing a Bessel beam propagating through a flat multilevel diffractive lens (MDL). This study highlights the impact of the MDL illuminated by a Bessel beam with suppressed sidelobes generated from a binary axicon. The resulting Bessel bottle beam exhibits a series of low- or zero-intensity zones interleaved with high-intensity regions, with periods ranging from 0.2 to 1.36 mm along the beam propagation direction. The transverse intensity profiles of these regions remain shape-invariant over long distances in free space, and thereby, the nondiffracting range of the micron-sized optical bottle beam exceeds 5 cm. We also observe that the far-field output from the MDL, when illuminated by a Bessel beam, offers advantages over that of conventional focusing lenses. Furthermore, this technique can operate on ultrafast time scales (from pico- to femtoseconds) due to the high damage thresholds of the binary axicon and MDL, enabling the generation of high-power optical bottle beams. Ultimately, our experimental approach paves the way for various applications, including high-resolution biological imaging in turbid media, particle manipulation, micromachining, and harmonic generation, by leveraging the spatial landscape of the optical bottle beam.
18-02-2026 Read MoreSpatio-spectral correlations in interferenceless coded aperture correlation holography with vortex speckles
Interferenceless coded aperture correlation holography (I-COACH) is a computational imaging method that enables three-dimensional information of an object to be obtained without the need for two-beam interference. For the first time, in this study, we propose and demonstrate I-COACH with vortex speckles (I-COACH-VS). The vortex speckle distribution is generated by designing a unique coded mask by combining several spiral phases with different topological charges and linear phases using the transport of the amplitude into the phase based on the Gerchberg-Saxton algorithm (TAP-GSA). The spiral phase generates multiple beams carrying different orbital angular momentum, and the linear phase is used to map the beams at different locations within the image sensor to achieve a random vortex speckle distribution. The recently developed Lucy-Richardson-Rosen algorithm (LRRA) is used for image reconstruction. The theory, simulation studies, design of a coded mask by TAP-GSA, fabrication of coded masks by photolithography, and experimental demonstration of I-COACH-VS are presented. We believe that the developed method will be impactful in fields such as incoherent digital holography and computational imaging.
19-06-2025 Read MoreGenerating high-harmonic array beams
The demand for spatially structured ultrashort beams at shorter wavelengths is high, and their adaptability in potential applications such as imaging, metrology, and attosecond science is undeniable. In this work, we present the generation of high-harmonic array beams. We utilize ultrashort structured array beams in the near-infrared wavelength as the pump source to reliably generate extreme-ultraviolet array beams at the tenth harmonic of the pump wavelength. The pump array beams showed shape-invariant free space propagation and exhibited a self-healing ability against adverse spatial effects introduced by aberrations. Moreover, we found that the spatial profile of these array beams remained unchanged for any polarization state, a unique feature that enhances their versatility. The interaction of shape-invariant array beams with an argon gas jet in a two-color pump configuration generated high harmonics consisting of both weak odd and even orders, a suppression of odd harmonics from the 13th to the 17th order when driven by two-color laser fields, but a strong 10th order harmonic appeared in the extreme-ultraviolet. This 10th harmonic unveiled a spatial distribution, including a unique string structure that is a hallmark of array beams. This extreme nonlinear optical process of structured high-harmonic generation is a significant advancement that offers a new degree of freedom for generating diverse structured harmonics in extreme ultraviolet and soft x-ray regimes.
13-02-2025 Read More