Unveiling bulk and surface radiation forces in a dielectric liquid

Astrath, Nelson Guilherme Castelli (author), Flizikowski, Gabriel Antonio Siqueira (author), Anghinoni, Bruno (author), Malacarne, L. C. (author), Baesso, Mauro L. (author), Požar, Tomaž (author), Partanen, M. (author), Brevik, Iver Håkon (author), Razansky, D. (author), Bialkowski, Stephen Edward (author)

Precise control over light-matter interactions is critical for many optical manipulation and material characterization methodologies, further playing a paramount role in a host of nanotechnology applications. Nonetheless, the fundamental aspects of interactions between electromagnetic fields and matter have yet to be established unequivocally in terms of an electromagnetic momentum density. Here, we use tightly focused pulsed laser beams to detect bulk and boundary optical forces in a dielectric fluid. From the optical convoluted signal, we decouple thermal and nonlinear optical effects from the radiation forces using a theoretical interpretation based on the Microscopic Ampère force density. It is shown, for the first time, that the time-dependent pressure distribution within the fluid chiefly originates from the electrostriction effects. Our results shed light on the contribution of optical forces to the surface displacements observed at the dielectric air-water interfaces, thus shedding light on the long-standing controversy surrounding the basic definition of electromagnetic momentum density in matter.

• Language: English
• Keywords: electrostriction, electromagnetic field, photo-induced lensing, elastic waves
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.04.2022
• Year: 2022
• Number of pages: Str. 1-10
• Numbering: Vol. 11, art. 103
• PID: 20.500.12556/RUL-136265
• UDC: 535.13:537.8
• ISSN on article: 2047-7538
• DOI: 10.1038/s41377-022-00788-7
• COBISS.SI-ID: 105505795
• Publication date in RUL: 21.04.2022

Record is a part of a journal

• Title: Light, science & applications
• Shortened title: Light sci. appl.
• Publisher: Nature Publishing Group
• ISSN: 2047-7538
• COBISS.SI-ID: 523258905

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 20.04.2022
• Applies to: Published

Secondary language

• Language: Slovenian
• Title: Razkritje sevalnih sil na površini in v notranjosti dielektrične tekočine

Abstract

Natančen nadzor interakcij med svetlobo in snovjo je ključnega pomena za številne metodologije optičnih manipulacij in karakterizacij materialov. Poleg tega igra zelo pomembno vlogo tudi v številnih nanotehnoloških aplikacijah. Kljub temu pa je potrebno temeljne vidike interakcij med elektromagnetnim poljem in snovjo še nedvoumno določiti v smislu gostote gibalne količine elektromagnetnega polja. Za zaznavanje sevalnih sil na površini in v notranjosti dielektrične tekočine smo uporabili tesno fokusirane laserske bliske. Iz zapletenega optičnega signala smo z uporabo teoretične interpretacije, ki temelji na gostoti mikroskopske Ampèrove sile, ločili toplotne in nelinearne optične učinke od sevalnih sil. Prvič je prikazano, da časovno odvisna porazdelitev tlaka znotraj tekočine izvira pretežno iz elektrostrikcijskih učinkov. Naši rezultati osvetljujejo prispevek optičnih sil k površinskim pomikom, opaženih na dielektrični meji zrak-voda, s čimer osvetljujejo dolgoletno polemiko o osnovni definiciji gostote gibalne količine elektromagnetnega polja v snovi.

• Keywords: elektrostrikcija, elektromagnetno polje, fotoinducirano lečenje, elastični valovi