In a certain partially-absorbing medium, light of frequency 4.8*10^14Hz is found to have a wavelength (in the medium) of 360 nm, and the amplitude of its electric field strength decays exponentially by a factor of 5.0 in a distance of 0.35 mm (i.e., after travelling 0.35 mm, the electric field amplitude is reduced to one fifth of its original value). What is the complex index of refraction of the medium at this frequency?