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.

N.G.C.Astrath;G.A.S.Flizikowski;B.Anghinoni;L.C.Malacarne;M.L.Baesso;T.Po?ar;M.Partanen;I.Brevik;D.Razansky;S.E.Bialkowski

Department of Physics,Universidade Estadual de Maringá,Maringá,PR,Brazil;Faculty of Mechanical Engineering,University of Ljubljana,Ljubljana,Slovenia;Department of Electronics and Nanoengineering,Aalto University,Aalto,Finland;Department of Energy and Process Engineering,Norwegian University of Science and Technology,Trondheim,Norway;Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology,Faculty of Medicine,University of Zurich,Zurich,Switzerland;Institute for Biomedical Engineering,Department of Information Technology and Electrical Engineering,ETH Zurich,Zurich,Switzerland;Department of Chemistry and Biochemistry,Utah State University,Logan,UT,USA

光：科学与应用（英文版）

[1]N.G.C.Astrath;G.A.S.Flizikowski;B.Anghinoni;L.C.Malacarne;M.L.Baesso;T.Po?ar;M.Partanen;I.Brevik;D.Razansky;S.E.Bialkowski-.Unveiling bulk and surface radiation forces in a dielectric liquid)[J].光：科学与应用（英文版）,2022(05):925-934

electrostriction

Unveiling,bulk,surface,radiation,forces,dielectric,liquid,Precise,control,light,matter,interactions,critical,many,optical,manipulation,material,characterization,methodologies,further,playing,paramount,role,host,nanotechnology,applications,Nonetheless,fundamental,aspects,between,electromagnetic,fields,have,yet,established,unequivocally,terms,momentum,density,Here,tightly,focused,pulsed,laser,beams,detect,boundary,fluid,From,convoluted,signal,decouple,thermal,nonlinear,effects,from,using,theoretical,interpretation,Microscopic,Amp,It,shown,first,that,dependent,pressure,distribution,within,chiefly,originates,Our,results,contribution,displacements,observed,air,water,interfaces,thus,shedding,long,standing,controversy,surrounding,basic,definition

0.626443