LAUSR

Interference resides deeply in our understanding of the wave properties of light. In this paper, the century famous Sagnac effect is demonstrated to be independent of the rotation axis position, using a rotating ring optical fiber in a straightforward laboratory experiment. A simple theoretical explanation for this result is given for any arbitrary closed loop interferometer. The level of this discussion should be suitable for undergraduate physics or engineering courses where electromagnetic theory and optics are discussed. The experiment described utilizes basic and important aspects in modern optics which every science student should acquire.