Physics

Problem

633\,\text{nm}

laser beam strikes two aluminum surfaces at normal incidence. Surface A has an rms roughness of

5\,\mu\text{m}

, and Surface B has an rms roughness of

0.10\,\mu\text{m}

. Observed on a screen

1\,\text{m}

beyond each surface, which surface produces the brighter central spot, and briefly justify your answer.