A helium-neon laser of the type frequently found in physics laboratories has a beam power of 7.00 mW at a wavelength of 633 nm. The beam is focused by a lens to a circular spot whose effective diameter may be taken to be equal to 2.00 wavelengths.
Evaluate the intensity of the focused beam.
Find the radiation pressure exerted on a tiny perfectly absorbing sphere whose diameter is that of the focal spot.
Evaluate the force exerted on this sphere.
Find the magnitude of the acceleration imparted to it. Assume a sphere density of 4.50×103kg/m3.