Optical excitation and detection of high-frequency coherent phonons and magnons

Abstract

The goal of this work is to obtain better control over all-optical excitation and detection of high-frequency collective excitations, in particular - phonons and magnons. Phonons- a collective movement of atoms in the lattice, and magnons- excitations of a spin system in magnetically ordered materials, recently became the prospective alternative to electrons in quantum computing or in general, information technology. In the scope of this thesis, we present a novel approach to the resonant excitation of fundamental magnon mode in a thin ferromagnetic film of Iron-Gallium alloy, as well as enhanced detection sensitivity of propagating coherent phonon wave packet exploiting giant photo-elasticity of exciton-polaritons in GaAs/AlAs superlattice. Additionally, a possible way to miniaturize the all-optical set-ups for manipulation of collective excitations is proposed by implementing a passively mode-locked semiconductor laser diode.