In some kinds of optical spectroscopy, such as photoluminescence and Raman spectroscopy, a laser beam exits from a pupil and is focused on a sample to stimulate electromagnetic radiation from the sample. The focusing lens generally has an antireflective coating preventing any light loss. Suppose a 80 mW laser is placed 3.40 meter from the lens, which has a focal length of 7.00 centimeter.
(a) Compute how far from the lens should the sample be placed therefore that an image of the laser exit pupil is formed on the surface of the sample?
___cm
(b) If the diameter of the laser exit pupil is 5.00 millimeter, determine the diameter of the light spot on the sample?
___μm
(c) Determine the light intensity at the spot?
___ W/m2