Phase shift formula in stimulated Brillouin scattering

[eahaidar]

Good morning
I need to ask about the exact formula for the phase shift used in stimulated Brillouin scattering especially in the phase shifter thank you

 

[UltrafastPED]

What have you already found? This is a pretty broad topic.

 

[eahaidar]

What have you already found? This is a pretty broad topic.

What I know is usually the imaginary part of the complex gain but I really want to know that there is a coefficient other than go which is power over effective area
I need to know if also the effective length is also multiplied to this constant

 

[UltrafastPED]

Which books are you using?

 

[eahaidar]

What I know from any book that you derive from the complex gain the real and imaginary part
The imaginary part is related to the phase but I need to know what factors multipled to this imaginary part??