We apply the transformation optical technique to modify or improve conventional refractive and gradient index optical imaging devices. In particular, when it is known that a detector will terminate the paths of rays over some surface, more freedom is available in the transformation approach, since the wave behavior over a large portion of the domain becomes unimportant. For the analyzed configurations, quasi-conformal and conformal coordinate transformations can be used, leading to simplified constitutive parameter distributions that, in some cases, can be realized with isotropic index; index-only media can be low-loss and have broad bandwidth. We apply a coordinate transformation to flatten a Maxwell fish-eye lens, forming a near-perfect relay lens; and also flatten the focal surface associated with a conventional refractive lens, such that the system exhibits an ultra-wide field-of-view with reduced aberration.
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http://dx.doi.org/10.1364/OE.18.021238 | DOI Listing |
Nat Commun
January 2025
Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
Aberration layers (AL) often present significant energy transmission barriers in microwave engineering, electromagnetic waves, and medical ultrasound. However, achieving broadband ultrasonic focusing through aberration layers like the human skull using conventional materials such as metals and elastomers has proven challenging. In this study, we introduce an inverse phase encoding method employing tunable soft metalens to penetrate heterogeneous aberration layers.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Department of Physics, University of Washington, Seattle, WA, USA.
Wide field of view and light weight optics are critical for advanced eyewear, with applications in augmented/virtual reality and night vision. Conventional refractive lenses are often stacked to correct aberrations at a wide field of view, leading to limited performance and increased size and weight. In particular, simultaneously achieving a wide field of view and large aperture for light collection is desirable but challenging to realize in a compact form-factor.
View Article and Find Full Text PDFSci Rep
December 2024
Research Group Biomedical Imaging Physics, Department of Physics, TUM School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany.
Light Sci Appl
January 2025
Chair in Hybrid Nanosystems, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany.
Multilayered van der Waals (vdW) materials are semiconductors composed of atomically thin crystal layers, held together by weak vdW forces. They offer unique crystal structures and electronic properties, distinct from conventional semiconductors, making them a promising platform for linear and nonlinear optics. In this context, the large refractive indexes given by highly polarizable transition metals, combined with excitonic resonances and unconventional crystalline structures, provides a toolbox for exploring non-linear physics and strong light-matter interactions with unprecedented opportunities for nanoscale optics.
View Article and Find Full Text PDFAdv Healthc Mater
December 2024
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
Astrocytes, integral components of the central nervous system, are increasingly recognized for their multifaceted roles beyond support cells. Despite their acknowledged importance, understanding the intricacies of astrocyte morphological dynamics remains limited. Our study marks the first exploration of astrocytes using optical diffraction tomography (ODT), establishing a label-free, quantitative method to observe morphological changes in astrocytes over a 7-day in-vitro period.
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