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Homework Help: About thin film (max bright/dark)

  1. Apr 22, 2016 #1
    1. The problem statement, all variables and given/known data
    2. Relevant equations

    3. The attempt at a solution
    SiO2 as the thin film,when light entry SiO2 and Si then the reflected light has 180 phase change,
    for dark fringes
    for bright fringes
    for dectect max of bright/dark,-1<=sinx<=1, then no idea to prove father
  2. jcsd
  3. Apr 23, 2016 #2

    Simon Bridge

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    Relate the thickness of the wedge to the wavelength of light ... notice there are seven fringes, so how many wavelengths of light thick is the widest part of the wedge?
  4. Apr 23, 2016 #3
    could you possibly explain more? still not understand..
  5. Apr 23, 2016 #4


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    Do you know what "t"means?
    How thick is the oxide at the thinnest part?
  6. Apr 23, 2016 #5
    t=the thick of SiO2
  7. Apr 24, 2016 #6


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    The SiO2 thickness changes, as it is a wedge. You see a bright strip where the thickness t matches the condition 2nt = mλ.
    How thick is the SiO2 wedge at the thinnest part? Do you see it bright or dark?
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