What is the definition of interferometry?
The process of splitting a waveform (typically light), then recombining the waveforms after they have travelled a path to detect and measure any change in phase between the two – the recombing process is the “interference”. A simple example of waveform interference can be observed when ocean waves coming from different directions “interfere” with one another. This may result in a larger wave if the peaks of the waves combine, or a diminished wave if the peaks of one wave meet the troughs of the other. Optical gyroscopes use waveform interferometry as a result of the Sagnac effect to measure rotation.