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Homework Help: Finding electric field incident on a medium

  1. Jun 23, 2011 #1
    \Gamma1. The problem statement, all variables and given/known data
    if an electric field is travelling in air and hits a medium n2. then there will be three fields present:

    the incident electric field
    the reflected electric field
    and the transmitted electric field.

    the electric field in medium 1 would be:

    E(z,t)=Ei(exp(-jkz)+[itex]\Gamma[/itex]exp(jkz))cos(wt-kz) assuming it is travelling in the z direction

    where gamma is the reflection cofficent and Ei is incident amplitude of the field.

    and the felid in medium two would be:
    E(z,t)=Ei([itex]\tau[/itex]exp(-jkz))cos(wt-kz) where tau is the transmission coffecient

    i was wondering if the angle of incidence any affect of the fields. for example if the original e field was incident on the normal angle would it affect the field in medium 2 or the relfected field. if so how?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jun 23, 2011 #2
    The angle of incidence is actually quite important since the transmission and reflexion coefficient are function of the incidence angle (I think they are usually called Fresnel coefficient; actually the square modulus are the Fresnel coefficient). Furthermore, the transmitted angle is also function of the incident angle (See Snell-Descartes law).

    I would also suggest that you don't mix complex wave and cosine wave expression since they complicate a lot any attempt when working with waves.
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