Mach-Zehnder interferometer with absorbing Fabry-P\'erot cavities

A Mach-Zehnder interferometer with absorbing Fabry-P'{e}rot cavities is used to measure the optical phase differences upon rotation around a vertical axis. The details of the expected experimental results are described based on the idea that a conducting medium can introduce phase differences due to changes in material conductivity that are expected to occur when a medium moves with respect to a reference frame. Experimental details and results are discussed.