Optical cavity mode dynamics and coherent phonon generation in high- Q micropillar resonators

S. ANGUIANO; A. E. BRUCHHAUSEN; I. FAVERO; I. SAGNES; A. LEMAÎTRE; N. D. LANZILLOTTI-KIMURA ; A. FAINSTEIN

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

AMER PHYSICAL SOC

Lugar: New York; Año: 2018 vol. 98 p. 13816 - 13816

1050-2947

We study the temporal dynamics of photoexcited carriers in distributed Bragg reflector based semiconductormicropillars at room temperature. Their influence on the process of coherent phonon generation and detectionis analyzed by means of pump-probe microscopy. The dependence of the measured mechanical signatures onlaser-cavity detuning is explained through a model that accounts for the varying light-cavity coupling existentduring the ultrashort times that pump and probe pulses dwell within the structure. To do so, we first explain theoptical mode dynamics with an electron-hole diffusion model that accounts for the escape of carriers from theprobed area, as well as their recombination in the bulk and on the free surfaces. We thus show that the latter isthe most influential factor for pillars below ∼10 μm, where 3D confinement of the optical and mechanical fieldsbecomes relevant.