Proposal for a New Michelson-Morley Experiment Using a Single Whispering   Spherical Mode Resonator
  A new Michelson-Morley experiment is proposed by measuring the beat frequency of two near degenerate modes with orthogonal propagation in a single spherical resonator. The unique properties of the experiment allow: 1. Substantial common mode rejection of some noise sources: 2. Simple calculation of the signal if Special Relativity is violated. We show that optimum filtering may be used to increase the signal to noise ratio, and to search for a preferred direction of the speed of light. Using this technique we show that a sensitivity limit of order 7.10^-19 is possible by integrating data over one month. We propose methods to veto systematic effects by correlating the output of more than one experiment. 
Michael Edmund Tobar, John Gideon Hartnett and James David Anstie