Mathematics behind this In an isotropic medium a propagating electromagnetic wave can be written as: E(t, X)=eoe i(ot-2水kx) Ene i2(fi-k.x) Where e is the vector electric field t is time, x is position and k is wave-vector(unit vector in direction of propagation divided by wavelength 2= velocity of light/frequency o is frequency in radians/second, f is frequency in cycles/second 02/25/02 12.540Lec0602/25/02 12.540 Lec 06 12 Mathematics behind this • In an isotropic medium a propagating electromagnetic wave can be written as: • Where E is the vector electric field, t is time, x is position and k is wave-vector (unit vector in direction of propagation divided by wavelength λ = velocity of light/frequency ω is frequency in radians/second, f is frequency in cycles/second. r E ( t,x ) = E 0 e −i(ωt− 2 πk.x) = E 0 e −i2 π ( ft − k.x)