[22p-C102-1~16] 22.1 Joint Session M "Phonon Engineering"

▼ [22p-C102-12] Parabolic thermal lenses for focusing and collimating ballisic heat fluxes

〇(M2C)Dhanishtha Singh¹, Roman Anufriev¹, Masahiro Nomura¹ (1.The Univ. of Tokyo)

Keywords:Parabolic lens, Ballistic phonon tranport, Focusing and collimation

Parabolic lenses have a wide range of applications in various branches of science and technology because of their reversible reflective properties. Here, we propose using the parabola's reflective property for heat flux manipulations. We use the Monte Carlo and the ray-tracing approach, in which phonon wavepackets are approximated as phonon quasiparticles traveling in straight lines, and the path of each phonon is tracked independently. Using parabolic lens structure, we showcase two effects: focusing and collimation of heat using ballistic phonon transport. Focusing of phonons at the parabola's focal point occurs when incident phonons are parallel to its axis of symmetry, referred to as directional phonons, undergo scattering from the parabolic surface. The reverse effect of focusing is collimation. Phonons become collimated along the Y-axis after undergoing boundary scattering when launched from the parabola's focus.