HW to turn in Thursday (F) or Friday (A)

1.  Find out about a few examples of how holography is used today.  Or if you're feeling ambitious, suggest some uses for it.

2.  Diffraction question

You are sending light through a diffraction grating that has 300,000 slits/openings per meter.  You aim a blue laser at it (wavelength = 475 x 10^-9 m).  The laser and grating is 1-m from a wall.  Find:

a.  the value for d (the distance between the slits)
b.  the diffraction angle for a first order (n = 1) image
c.  the distance between the central image (n = 0) and the first (n = 1) image.  Use trig here.
d.  Draw this situation.
e.  How many dots would you see on the wall?
f.  If you used a red laser, would the dot spacing change?  If so, how?