Generating acoustic holograms beyond the hyperbolic approximation

Abstract

Transcranial focused ultrasound has proven to be an effective method for the treatment of neurological disorders, offering a non-invasive and highly precise approach for the targeting of specific brain regions. In this context, ultrasound holograms have been shown to be capable of focusing through the human skull using low-cost 3D-printed acoustic holographic lenses, where a wavefront is encoded into the height of the pixels of a lens. When the coding is performed at the holographic plane, i.e., a planar surface in front of the transducer, the reconstructed wavefront is approximated by a hyperbolic phase profile in the thin lens approximation. However, as the thickness of the physical lens is beyond the thin lens approximation, this results in aberrations. In this work, a new strategy is proposed matching the phase of the field produced at the exit of the lens to the target phase in a whole holographic volume. The method is validated using analytic and simulations techniques. Results show that this phase-matching approach provides better focusing performance over traditional methods and, therefore, might be used for accurate hologram synthesis in practical applications.

@inproceedings{VegasLuqueFA2025,
 author = {Víctor Vegas-Luque and Diana Andrés and Alba Eroles-Simó and Juan J. Rodríguez-García and Francisco Camarena and Noé Jiménez},
 booktitle = {Forum Acusticum Euronoise 2025: 11th Convention of the European Acoustics Association. Málaga, Spain. 23-26 June},
 editor = {Conference proceedings},
 month = {09},
 organization = {European Acoustics Association, Sociedad Española de Acústica},
 pages = {1-1},
 series = {Oral},
 title = {Generating acoustic holograms beyond the hyperbolic approximation},
 year = {2025}
}