История развития методов и интерференционных приборов для измерения малой разности оптических фаз (обзор)

Methods of interferometry, which are used to measure very small phase differences, are considered.in fundamental and applied problems. It is shown that the first improvements in interferometricmethods for measuring small phase differences for recording various physical phenomena in the secondhalf of the XIX - early XX centuries. carried out by I.A. Fizeau, A.A. Michelson, E. Morley, Lord Rayleigh, D.C. Millerand J.M. Sagnac. It was also shown that the most sensitive method of modulation interferometrywas created in the period 1949-1952. Soviet radiophysicists A.A. Andronov, I.L. Berstein andG.S. Gorelik. It is noted that the modulation interferometry method could be implemented even in1914 with a photocell on an external photoelectric effect, or in 1923 with a photocell oninternal photoelectric effect (photodiode). However, then professional opticians used traditionalmethods for measuring small phase differences, and radiophysics as a science was just beginning its formation.It is shown that the methods of electrical and photoelectric harmonic analysis developed inlate XIX - early XX centuries could find successful application in interferometry, but by that time,when they could find practical use, they were almost completely forgotten.