4点法による干渉縞端数の自動測定
1992 年 58 巻 4 号 p. 679-683
詳細
1992 年 58 巻 4 号 p. 679-683
An automatic system has been developed for the measurement of interference fringe fractions by four point method. A parallel and rectilinear fringe pattern made by Michelson laser-interferometer is observed by four photo-detectors. Through four uniformly spaced slits, detectors collect the light of corresponding regions of the fringe pattern, and the output signals are transmitted to a computer after passing through an amplifier and an AD converter. In the computer, an interference fringe fraction at the middle point of two central slits is calculated. Theoretical analysis is made for errors in measured values of fringe fractions caused by the variation of amplification of the detector outputs and the slit spaces. Experiments show the interference fringe fraction is determined in the accuracy better than ±0.005 by this method.
