An optician is performing Young's double-slit experiment for his clients. He directs a beam of laser light to a pair of parallel slits, which are separated by 0.146 mm from each other. The portion of this light that passes through the slits goes on to form an interference pattern upon a screen, which is 4.50 meters distant. The light is characterized by a wavelength of 557 nm. (a) What is the optical path-length difference (in µm) that corresponds to the third-order bright fringe on the screen? (This is the third fringe, not counting the central bright band, that one encounters moving from the center out to one side.) answer in µm (b) What path-length difference (in µm) corresponds to the third dark fringe that one encounters when moving out to one side of the central bright fringe? answer in µm

An optician is performing Young's double-slit experiment for his clients. He directs a beam of laser light to a pair of parallel slits, which are separated by 0.146 mm from each other. The portion of this light that passes through the slits goes on to form an interference pattern upon a screen, which is 4.50 meters distant. The light is characterized by a wavelength of 557 nm. (a) What is the optical path-length difference (in µm) that corresponds to the third-order bright fringe on the screen? (This is the third fringe, not counting the central bright band, that one encounters moving from the center out to one side.) answer in µm (b) What path-length difference (in µm) corresponds to the third dark fringe that one encounters when moving out to one side of the central bright fringe? answer in µm