A single-mode optical fiber has an attenuation of 0.3dB/km when operating at wavelength of 1.1 m. The fiber core diameter is 4 m and bandwidth is 500 MHz. Find threshold optical power for stimulated Brillouin scattering.

• A. 11.20 mw
• B. 12.77 mw
• C. 13.08 mw
• D. 12.12 mw