Chiral optical tweezers in the $T$-matrix formalism.
Patti F., Saija R., Denti P., Pellegrini G., Biagioni P., Iat`i M.A., Maragò O.M.
II - Fisica della materia
Aula 32B-2 - Mercoledì 19 h 09:00 - 13:00
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Chirality is a key property of many natural structures, from DNA to spiral galaxies. An object is chiral if it lacks symmetry by reflection, so it is not superimposable to its mirror image. A circular polarized electromagnetic wave is also a chiral object. In this work we focus on the study of radiation forces and torques that stem from the interaction between chiral fields and chiral matter as a consequence of the conservation of linear and angular momentum. After defining the constitutive relations for the chiral medium and using Bohren's decomposition, the scattering problem for an optically active material is solved. The $T$-matrix formalism and the angular spectrum representation method are exploited in order to face the problem of optical trapping. This general light scattering framework opens perspectives for modeling optical forces on biological materials where optically active aminoacids and carbohydrates are present.