The role of electrostriction in the generation of acoustic waves by optical forces in water

Astrath, Nelson Guilherme Castelli (author), Anghinoni, Bruno (author), Flizikowski, Gabriel Antonio Siqueira (author), Zanuto, V. S. (author), Malacarne, Luis Carlos (author), Baesso, Mauro L. (author), Požar, Tomaž (author), Razansky, D. (author)

We present semi-analytical solutions describing the spatiotemporal distributions of temperature and pressure inside low-absorbing dielectrics excited by tightly focused laser beams. These solutions are compared to measurements in water associated with variations of the local refractive index due to acoustic waves generated by electrostriction, heat deposition, and the Kerr effect at different temperatures. The experimental results exhibited an excellent agreement with the modeling predictions, with electrostriction being the dominant transient effect in the acoustic wave generation. Measurements at show that the thermoelastic contribution to the optical signal is significantly reduced due to the low thermal expansion coefficient of water at this temperature.

• Language: English
• Keywords: electrostriction, radiation forces, photo-induced lensing effect, pressure-transients, Kerr lens
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 7 str.
• Numbering: Vol. 29
• PID: 20.500.12556/RUL-143895
• UDC: 534
• ISSN on article: 2213-5979
• DOI: 10.1016/j.pacs.2022.100445
• COBISS.SI-ID: 138249987
• Publication date in RUL: 18.01.2023

Record is a part of a journal

• Title: Photoacoustics
• Publisher: Elsevier
• ISSN: 2213-5979
• COBISS.SI-ID: 519718169

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.

Secondary language

• Language: Slovenian
• Title: Vloga elektrostrikcije pri tvorbi akustičnih valov z optičnimi silami v vodi

Abstract

Predstavljamo pol-analitične rešitve, ki opisujejo prostorsko-časovne porazdelitve temperature in tlaka znotraj dielektrikov z nizko absorpcijo, ki jih vzbujamo s tesno fokusirani laserski žarki. Te rešitve primerjamo pri različnih temperaturah z meritvami v vodi, ki so povezane s spremembami lokalnega lomnega količnika kot posledica preleta akustičnih valov, ki nastanejo z elektrostrikcijo in z odlaganjem toplote ter s Kerrovim učinkom. Eksperimentalni rezultati so pokazali odlično skladnost z napovedmi modeliranja, pri čemer je bila elektrostrikcija prevladujoč prehodni učinek pri ustvarjanju akustičnih valov. Meritve pri 4,0 °C kažejo, da je termoelastični prispevek k optičnemu signalu znatno oslabljen zaradi nizkega toplotnega razteznega koeficienta vode pri tej temperaturi.

• Keywords: elektrostrikcija, sevalna sila, učinek fotoinduciranega lečenja, prehodni tlak, Kerrova leča