Open AccessEffect of crystalline family and orientation on stimulated Brillouin scattering in whispering-gallery mode resonators
Author(s) -
Souleymane Diallo,
JeanPierre Aubry,
Yanne K. Chembo
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.029934
Subject(s) - brillouin scattering , whispering gallery wave , optics , resonator , materials science , brillouin zone , acoustic wave , scattering , crystal (programming language) , laser , physics , computer science , programming language
Ultra-high Q whispering-gallery mode resonators pumped by a continuous-wave laser are known to enhance stimulated Brillouin scattering when optimal resonance and phase-matching conditions are met. In crystalline resonators, this process depends critically on the crystal orientation and family, which impose the elastic constants defining the velocity of the acoustic waves. In this article, we investigate the effect of crystalline orientation and family on this velocity which is proportional to the Brillouin frequency down-shift. In particular, the study is based on the development of a model and numerical simulations of acoustic wave velocities that propagate along the periphery of four fluoride crystals, namely calcium, magnesium, lithium and barium fluoride. We find that depending on the crystal and its orientation, the frequency excursion around the Brillouin offset can vary from few tens of kHz to more than a GHz.