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Homework Help: Refraction of Light in a laser beam

  1. Mar 12, 2006 #1
    Question
    A laser beam travels from air into a symmetrical prism at right angles close to its upper edge. The refractive index of the prism material n = 1.4 and its angle is 30 degrees.

    i)
    Calculate the critical angle for the prism-air interface.
    Possible Answer:
    Critical angle = arcsine(1/n)
    arcsine(1/1.4)
    = 45.585 degrees

    ii)
    After passing through the prism, what angle does the beam make with the incident ray?
    Possible Answer:
    Sine Angle = (n of prism)(Sine30)/n of air
    = ((1.4)(Sin30))/1.0
    Sine Angle = 0.7
    Angle = 44.427 degrees

    Are these correct?
     
  2. jcsd
  3. Mar 12, 2006 #2
    n = sin(A/2 + x/2)/sin(A/2). Here critical angle is x. 2 is correct.
     
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