Theoretical study on the stimulated Brillouin scattering in a sub-wavelength anisotropic waveguide: Acousto-optical coupling coefficients and effects of transverse anisotropies
arXiv:1611.08792 · doi:10.1364/JOSAB.34.002599
Abstract
A theoretical study on the stimulated Brillouin scattering (SBS) in a sub-wavelength anisotropic waveguide is conducted. The optical, photoelastic and mechanical anisotropies of the waveguide materials are all taken into account. First, the integral formulae for calculating the acousto-optical coupling coefficients (AOCCs) due to the photoelastic and moving interface effects in SBS are extended to an optically anisotropic waveguide. Then, with the extended formulae, the SBSs in an elliptical nanowire with strong transverse anisotropies are simulated. In the simulations, the elastic fields are computed with the inclusion of mechanical anisotropy. Observable effects of the strong transverse anisotropies are found in numerical results. Most notably, the SBS gains of some elastic modes are found to be very sensitive to the small misalignment between the waveguide axes and the principal material axes. Detailed physical interpretations of this interesting phenomenon are provided. This interesting phenomenon implies an attractive way for more sensitive tuning of the SBS gain without significantly changing the phononic frequency.
References in corpus (11)
- Interaction between light and highly confined hypersound in a silicon photonic nanowire
- Coherent coupling between radio frequency, optical, and acoustic waves in piezo-optomechanical circuits
- Brillouin Scattering Self-Cancellation
- Nonlinear radiation pressure dynamics in an optomechanical crystal
- Unifying Brillouin scattering and cavity optomechanics
- A Hamiltonian treatment of stimulated Brillouin scattering in nanoscale integrated waveguides
- Cascaded forward Brillouin scattering to all Stokes orders
- Brillouin resonance broadening due to structural variations in nanoscale waveguides
- Impact of nonlinear loss on Stimulated Brillouin Scattering
- Stimulated Brillouin scattering in metamaterials
- Stimulated Brillouin scattering enhancement in silicon inverse opal waveguides