A narrow green laser beam of wavelength λ1=532nm is incident at 30∘ to the normal on an aluminum surface whose rms microscopic roughness is measured to be hrms=200nm. The same surface is later used with a telecommunications laser of wavelength λ2=1550nm at the same incident angle.
(a) Determine for the green laser whether the reflected light will be predominantly specular, predominantly diffuse, or a comparable mixture. Support your determination with quantitative or qualitative reasoning that incorporates the numerical data provided.
(b) Repeat the determination of part (a) for the infrared laser.
(c) Based on your answers to parts (a) and (b), predict which laser will produce the higher peak intensity in the specular direction and which will result in greater overall scattering into non-specular directions. Explain your reasoning.