Michaelson interferometer measurement line expansion coefficient of error how to reduce

Michaelson interferometer line expansion coefficient error reduction method: free of empty range, careful counting. There are several sources of MICHAELSON interferometer error in line expansion coefficient measurement: error in counting of fringes. Empty range is not eliminated. Error in judging the brightest and darkest position. To minimize the error, we need to avoid the empty range and count carefully. Michaelson interferometer, is 1883 American physicist Michaelson and Morey cooperation, for the study of ether drift and design and manufacture of precision optical instruments. It utilizes the split-amplitude method to produce a double beam for interference. By adjusting this interferometer, it is possible to produce iso-thickness interference fringes as well as iso-dipping interference fringes. Mainly used for length and refractive index measurements, if the interference fringe is observed to move a line, that is, the moving arm of M2 moves λ/2, which is equivalent to the thickness of the air film between M1 and M2 to change λ/2. It has important applications in modern physics and modern metrology, such as in the study of spectral lines of the fine structure and the use of light waves to calibrate the standard meter scale and other experiments. Using the principle of the instrument, a variety of specialized interferometers have been developed.