Index
getFiber
 [fiber, fWidth, n2I] = getFiber(sFiberName)
 [fiber, fWidth, n2I] = getFiber(sFiberName, bBirefringent)
 [fiber, fWidth, n2I] = getFiber(sFiberName, sBrand, bBirefringent)
    bBirefringent = true/false(default)
    fWidth = fMFD/2; % is radius