Rotating Michelson-Morley experiment based on a dual cavity cryogenic sapphire oscillator

Abstract

Recent experiments based on cryogenic microwave [1,2,3] and optical [4,5] oscillators have tested the isotropy of the speed of light (Michelson-Morley experiment) at sensitivities of the order of a part in 1015. Further improvements of the accuracy in this type of experiment are not expected due to the already long data set and systematic error limits [2]. We have constructed a new rotating Michelson-Morley experiment consisting of two cylindrical cryogenic sapphire resonators. By rotating the experiment our sensitivity to light speed anisotropy is increased, as the relevant time variations are at the rotation frequency where the frequency stability of the cryogenic oscillators is the best. Preliminary data has been analyzed using the frameworks of Robertson, Mansouri and Sexl (RMS) and the Standard Model Extension (SME), and the results are presented.