A long single$-$mode optical fiber has an attenuation of $0\mathrm{.}5dBkm-1$ when operating at a

wavelength of $1\mathrm{.}2m.$ The fiber core diameter is $6m$ and the laser source bandwidth is $600$

$MHz.$ Compare the threshold optical powers for stimulated Brillouin and Raman scattering within

the fiber at the wavelength specified.

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