Example of Interferometry Surface Texture A typical laser interferometer has a wavelength of 660nm. If the interferometer records light of full brightness when reflected from the bottom of the asperity, what brightness would you expect to record at the top of the two aperities? Rearrange diff = n/2 (make n the subject) laser Find n = 2.diff/2 Ans for 0.495, n=3 therefore dark Ans for 0.33, n=2 therefore light mirror Beam splitter camera 0.495 microns 1 10.33 microns