レーザーを用いた干渉縞計数方式測長における波長ゆらぎの影響
1980 年 9 巻 5 号 p. 289-295
詳細
1980 年 9 巻 5 号 p. 289-295
Effect of laser wavelength fluctuation on the data obtained by a fringe counting laser interferometer, being utilized for measurement of the line standard at NRLM, is experimentally studied by means of the Allan variance of the fluctuation. The fluctuation of the light source for the interferometer (Spectra-Physics Model 119) is measured from the beat note with the iodine stabilized He-Ne laser of NRLM. It is founded that the flicker FM noise for r>150 ms plays a dominant role to the measurement error due to the fluctuation and the standard deviation of measured value with the interferometer is estimated to be less than 3.5×10-8. √N/ (N-1) for τ=600s (typical measuring time for 1m line standard), where N is number of samples.
