Question

physics: optics
q1:
A 180 ?? laser produces a nearly parallel beam 20 ??2
in cross-sectional area at a wavelength
of 710 ??. Determine the amplitude of the electric field in the beam, assuming the wavefronts
are homogeneous and light travels in vacuum.

q2:
a) A light beam with an irradiance of 4 × 106 ?/?2
impinges normally on a surface
that reflects 65.0% and absorbs 35.0%. Calculate the resulting radiation pressure on the surface.
b)Compute the momentum of a green photon (? = 520 ??).

Answer 1

Q1 )   Intensity is given by

  

            

            

Q3) mometum of a photon