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I Scattering from lossy medium whose refractive index is unity

  1. Oct 11, 2018 #1
    Consider a thin transparent plate surrounded by air. The plate's refractive index is exactly the same as the air's, but it does have a small loss (say of the order of 1%).

    Let the plate be vertical and normal to our "page" or your computer screen. A laser beam passes through the plate at an acute angle such as 5 degrees, say from the lower right to the upper left.

    Now is there any mechanism in this system by which some of the light would be scattered towards the upper right? (FWIW, I arrived at this conjecture while following some train of thought that probably wouldn't interest anyone here).

    If there is such a process, where can I read more about it? Does it have a name? Would the scattered energy form a beam similar in width to the incident one?
  2. jcsd
  3. Oct 11, 2018 #2


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    For an absorptive material, the index of refraction becomes a complex quantity. Nevertheless it won't lead to scattering out of the plane defined by the normal to the surface and the incidence vector.
  4. Oct 11, 2018 #3
    Thank you!
    In my post, the question is about scattering within (consistent with) the constraint that you specified, but in a direction that is still counter intuitive. The direction I am asking about is similar to total internal reflection but with refractive index being the same as air.

    You note that absorption is included in a complex coefficient -- so if I understand correctly, the loss component can result in refraction-like bending?
  5. Oct 11, 2018 #4


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