What equation describes laser beam damping in air?

[dmriser]

This is a question for knowledge not for any assignment, but I was wondering what type of equation describes the damping or extinction that the light beam coming from a laser endures. I googled and couldn't find much although I may be using the wrong terminology. Could someone point me toward a reference or enlighten me on the subject?

I assume that the density of air will come into play as there will be more scattering and so will the distance but I can't find any equations or even begin to derive my own.

Thanks

 

[Claude Bile]

Net power loss will be determined by the loss induced by the medium that the laser beam propagates through.

Rayleigh scattering would be the primary source of loss at short wavelengths. Rayleigh scattering is indeed dependent on the particle density;

http://en.wikipedia.org/wiki/Rayleigh_scattering

The scattering cross section is related to the linear loss the exponential relationship P = P_0*e^(-/sigma*x).

Claude.

 

[dmriser]

That does the job, I can now make the calculations I wanted.. Thank you