An interferometer is set up to carefully measure changes in length. The laser source has a wavelenth of 632nm and the arms of the device are 11 m long.
a) How much would the phase of light that has traveled one of the paths have to be to go from perfectly constructive to perfectly destructive interference?
b) How much of a change in the length of the interferometer arm does this represent?
c) How much of a travel time difference does this represent?