Figure 9

Figure 9: The relation between the phase of the light field amplitudes at a beam splitter can be computed assuming a Michelson interferometer, with arbitrary arm length but perfectly-reflecting mirrors. The incoming field E0 is split into two fields E1 and E2 which are reflected atthe end mirrors and return to the beam splitter, as E3 and E4, to be recombined into two outgoing fields. These outgoing fields E 5 and E 6 are depicted by two arrows to highlight that these are the sum of the transmitted and reflected components of the returning fields. We can derive constraints for the phase of E1 and E2 with respect to the input field E0 from the conservation of energy: |E0|2 = |E5|2 + |E6 |2.