Brillouin mirror with inverted acoustic profile in presence of strong acoustic dispersion

Antonio Montes (1) , Carlos Montes (2) , Éric Picholle (2)

1 UPC - Universitat Politècnica de Catalunya = Université polytechnique de Catalogne [Barcelona]
2 INPHYNI - Institut de Physique de Nice

While usually negligible in standard optical fibers, the group velocity dispersion of acoustic waves may in some cases play a significant role in the dynamics of stimulated Brillouin scattering (SBS) in propagation medias with more complex structures, such as microstructured fibers. The usual 3-wave coherent model of SBS can be adapted to take a perturbative acoustic dispersion into account, but the slowly varying envelopes approximation does not hold for stronger values of the acoustic dispersion, which call for a more sophisticated inertial model of SBS. A new regime of SBS mirror with a spatially inverted acoustic profile is predicted in this limit. In presence of strong acoustic dispersion, this regime exhibits a higher conversion efficiency than the usual mirror in the dispersionless case, as well as nonlinear self-stabilization of the phase of the acoustic wave when the pump is strongly depleted. Formal calculations allow the identification of regions of strong dynamic dispersion.

Mots clés: Stimulated Brillouin scattering; 3-wave model; Photonic crystal fiber; superluminal

Mots clés: Diffusion Brillouin stimulée; modèle à 3 ondes; fibres microstructurées; supraluminique; dispersion

Domaines: Optique / photonique; Science non linéaire [physics]; Optique [physics.optics]

Antonio Montes, Carlos Montes, Éric Picholle. Brillouin mirror with inverted acoustic profile in presence of strong acoustic dispersion. Journal of the Optical Society of America B, 2021, 38 (2), pp.456-465. ⟨hal-02906584⟩