A 1.0mW laser beam with a wavelength of λ= 532nm encounters a double-slit, where the separation between the slits is 50:0 μm. The resulting di raction pattern is observed on a screen 20.0m away.
(a) Draw a diagram(s) of the system including all relevant information. Include what you would expect to see at the slit and at the screen.
(b) What is the distance between the m = +2 and m = - 2 di raction orders? List any assumptions you make.
(c) What is the phase di erence between wavefronts originating from the two slits, at a point on the screen located += Π/10m from the zero'th order?
(d) Brie y list the key di erences in the observed di raction pattern if the double-slit were replaced with a di raction grating with the same slit spacing.
The laser beam is now directed into a dilute sample containing spherical, metallic nanoparticles which are 5nm in diameter.
(e) Would you expect the laser to interact with the nanoparticles? If so how? Justify your answer.
(f) Assume that the nanoparticle is able to absorb photons at 520 nm. At what velocity does the nanoparticle need to move for the photon to be absorbed. Assess your answer.