Special Presentation: Mikko Partanen

    Monday, February 11, 2019 - 3:00pm
    Meinel 547

    Understanding and discovering light-generated optical shock waves and elastic waves in dielectrics


    Recently, the generation of elastic waves by light reflected from a mirror foil on a dielectric has been quantitatively measured for the first time by Požar et al. [1]. The discovery of Požar et al. is a special case of a much more general phenomenology of atomic density waves that are generated when light is partially reflected and partially transmitted through a dielectric. Fundamental and unified understanding of the dynamics of these atomic density waves is only possible by the mass-polariton (MP) theory of light developed by us recently [2], which combines the optical and elastic forces and enables solving the dynamical equation for the atoms in a dielectric.

    In this seminar, we review the foundations of the MP theory of light. We elaborate the classical field-theoretical background of the energy-momentum tensor of the MP theory [5], including its relation to the conservation laws, the Lorentz transformation of the energy-momentum tensor components, and the form-invariance of the field and the atomic mass density wave equations. We also discuss the challenges that must be overcome to be able to experimentally measure the mass transferred by the density wave of atoms. In particular, we consider the effect of reflections, absorption, the breakdown threshold irradiance of the material, and the relaxation effects by elastic waves.

    Speaker Bio(s): 

    Mikko Partanen
    Engineered Nanosystems Group
    Aalto University, School of Science
    Aalto, Finland