\(E_e=\frac{\epsilon_0 c}{2}E_0^2=1000W/m^2\)

\(E_0=\sqrt{\frac{2E_e}{\epsilon_0 c}}=870V/m\)

\(B_0=\frac{E_0}{c}=\frac{870 V/m}{3*10^8 m/s}=\frac{E_0}{c}=2.9*10^6 T\)