Articolo in rivista, 2018, ENG, 10.1016/j.jqsrt.2018.07.013

Optical tweezers and their applications

Polimeno P; Magazzù A; Iati' M A; Patti F; Saija R; Degli Esposti Boschi C; Donato M G; Gucciardi P G; Jones P H; Volpe G; Marago' O M

CNR-IPCF, Istituto per i Processi Chimico-Fisici, Viale F. Stagno d'Alcontres 37, Messina I-98158, Italy Institutionen för Fysik, Göteborgs Universitet, Origovägen 6 B, Göteborg I-41296, Sweden Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Universitàdi Messina, Viale F. Stagno d'Alcontres, 31, Messina I-98166, Italy CNR-IMM sezione di Bologna, Istituto per la Microelettronica e Microsistemi, Via P. Gobetti 101, Bologna I-40129, Italy Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK

Optical tweezers, tools based on strongly focused light, enable optical trapping, manipulation, and characterisation of a wide range of microscopic and nanoscopic materials. In the limiting cases of spherical particles either much smaller or much larger than the trapping wavelength, the force in optical tweezers separates into a conservative gradient force, which is proportional to the light intensity gradient and responsible for trapping, and a non-conservative scattering force, which is proportional to the light intensity and is generally detrimental for trapping, but fundamental for optical manipulation and laser cooling. For non-spherical particles or at intermediate (meso)scales, the situation is more complex and this traditional identification of gradient and scattering force is more elusive. Moreover, shape and composition can have dramatic consequences for optically trapped particle dynamics. Here, after an introduction to the theory and practice of optical forces with a focus on the role of shape and composition, we give an overview of some recent applications to biology, nanotechnology, spectroscopy, stochastic thermodynamics, critical Casimir forces, and active matter.

Journal of Quantitative Spectroscopy & Radiative Transfer 218 , pp. 131–?

Keywords

optical trapping, optical manipulation, t matrix

CNR authors

Patti Francesco, Gucciardi Pietro Giuseppe, Marago Onofrio, Donato Maria, Iati Maria Antonia, Degli Esposti Boschi Cristian

CNR institutes

IMM – Istituto per la microelettronica e microsistemi, IPCF – Istituto per i processi chimico-fisici