Fringes of equal inclination in the double-passed Michelson interferometer

The formation of fringes of equal inclination in the double-passed Michelson interferometer is discussed and a theoretical expression is obtained for the intensity distribution in the interference pattern. It is shown that the intensity distribution in these fringes undergoes a periodic modulation as the path difference in the interferometer is varied. Accurate measurements are possible with these fringes using a photometric setting criterion