We demonstrate the fabrication of volume holograms using two-photon polymerization with dynamic control of light exposure. We refer to our method as (3 + 1)D printing. Volume holograms that are recorded by interfering reference and signal beams have a diffraction efficiency relation that is inversely proportional to the square of the number of superimposed holograms. By using (3 + 1)D printing for fabrication, the refractive index of each voxel is created independently and thus, by digitally filtering the undesired interference terms, the diffraction efficiency is now inversely proportional to the number of multiplexed gratings. We experimentally demonstrated this linear dependence by recording M = 50 volume gratings. To the best of our knowledge, this is the first experimental demonstration of distributed volume holograms that overcome the 1/M limit.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.508097 | DOI Listing |
Phys Med Biol
January 2025
Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom.
Transcranial ultrasound is used in a variety of treatments, including neuromodulation, opening the blood-brain barrier, and high intensity focused ultrasound therapies. To ensure safety and efficacy of these treatments, numerical simulations of the ultrasound field within the brain are used for treatment planning and evaluation. This study investigates the accuracy of numerical modelling of the propagation of focused ultrasound through cranial bones.
View Article and Find Full Text PDFNanophotonics
April 2024
Department of Bio-Functions and Systems Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 Japan.
Metasurface holograms offer various advantages, including wide viewing angle, small volume, and high resolution. However, full-color animation of high-resolution images has been a challenging issue. In this study, a full-color dielectric metasurface holographic movie with a resolution of 2322 × 2322 was achieved by spatiotemporally multiplexing 30 frames with blue, green, and red color channels at the wavelengths of 445 nm, 532 nm, and 633 nm at the maximum reconstruction speed of 55.
View Article and Find Full Text PDFNanophotonics
December 2023
School of Physics and Astronomy, Faculty of Science, Monash University, Melbourne, Victoria 3800, Australia.
Two analog holographic wavefront sensors, for measurement of defocus, have been fabricated as both thin and volume phase transmission holograms in a self-developing photopolymer. This represents the first reported direct comparison of hologram regimes when designed for wavefront sensing. An analysis of the effect of crosstalk in the presence of one other aberration mode (astigmatism X (0/90°), coma X (horizontal), and primary spherical aberration) was carried out with each version of the sensor.
View Article and Find Full Text PDFIEEE Trans Image Process
October 2024
We study the visual quality judgments of human subjects on digital human avatars (sometimes referred to as "holograms" in the parlance of virtual reality [VR] and augmented reality [AR] systems) that have been subjected to distortions. We also study the ability of video quality models to predict human judgments. As streaming human avatar videos in VR or AR become increasingly common, the need for more advanced human avatar video compression protocols will be required to address the tradeoffs between faithfully transmitting high-quality visual representations while adjusting to changeable bandwidth scenarios.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!