Using this convention, the electric field vector of a left-handed circularly polarized wave is as follows: ( E x , E y , E z ) ∝ ∝ ( cos ⁡ ⁡ 2 π π λ λ ( c t − − z ) , − − sin ⁡ ⁡ 2 π π λ λ ( c t − − z ) , 0 ) .