For an electromagnetic wave propagating in +x direction the electric field is $$\overset{\rightarrow}{ E } = \frac{1}{\sqrt{2}}E_{yz} (y, z, t) (\hat{y}+\hat{z})$$ and the magnetic field is $$\overset{\rightarrow}{B} = \frac{1}{\sqrt{2}}E_{yz} (y, z, t) (\hat{y}+\hat{z})$$