The refractive index N = n, + in; of a certain material has values as specified in the table below. For which wavelength is the absorption of this material the lowest? [2 pt.] wavelength [um] nr ni 0.1 1.5 10-5 0.5 1.0 5 x 10-5 2 10-4 5 2.5 5 x 10-4 10 2.25 10-3 50 1.9 5 x 10-3 100 1.8 10-2