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Homework Help: E&M Fiber Amplifiers

  1. Dec 5, 2011 #1
    1. The problem statement, all variables and given/known data

    One of the most exciting developments in lightwave engineering is the Erbidium doped fiber amplifier (ERDF A). It is very quiet(low noise) has a bandwidth of hundreds of GHz and relatively low cost.The fiber is "pumped" by a semiconductor laser operating at 850nm and the light carrying the information at 1550nm is amplified. The 'attenuation'
    constant is given as u=-0.046m^-1. If I have 0.01mW entering the ERDFA
    and I would like to get 100mW out, how long should be my fiber amplifier?
    If the efficiency of the amplifier is 20% how much pumping power do I

    2. Relevant equations

    Loss Equation e^(-2*α(z1-z0)

    alpha is attenuation constant

    if the negative sign was removed. would this be a gain equation?

    3. The attempt at a solution

    I do not know where to start, the teacher said the wavelengths were irreverent.
  2. jcsd
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