The expression for an electric field in free space is , $\textbf{E}=E_{0}( \hat{x}+\hat{y}+j2 \hat{z} )e^{-j( \omega t-kx+ky)}$ where $x,y,z$ represent the special coordinates, $t$ represents time, and $\omega,k$ are constants.This electric field,
- does not represent a plane wave
- represents a circularly polarized plane wave propagating normal to the $z$-axis
- represents an elliptically polarized plane wave propagating along the $x – y$ plane
- represents a linearly polarized plane wave