Coupling Optical Modes and Elastic Modes

Hello,

I am trying to find the effects of elastic modes (vibrations) on optical modes in a SMF28 optical fiber in 2D.

I am using the solid mechanics model to first calculate the eigenfrequencies of the fiber in study 1, then in study 2 I am using the wave optics --> Mode Analysis module to see how the optical modes have changed because of the vibrations. I am trying to simulate brillouin scattering

I seem to be getting the same modes as when I am solving for the optical modes on its own. I'm not sure if putting them into a single study but in different steps will change the results.

How can I couple the 2 effects?

Thanks,
Dennis