- All rays leaving the laser are in phase .
- It varies in phase from point to point and moment to moment .
- The induced electromotive force and the current do not move along evenly together, that is, in phase .
- Generally the components of the signal that are in phase and out of phase with the primary signal are plotted separately .
- Our objective in such an areal arrangment of detectors is to ensure that the reflection signal is substantially in phase at all detectors .