A novel optical processing scheme for interferometric vibration measurement using a low coherence source with a fibre optic probe

A low coherence ("white light") interferometric approach to the measurement of vibration using a fibre optic probe to interrogate the vibrating surface is described. The recovery interferometer is a novel adaptation of a Michelson interferometer which provides two independent outputs, the relative phase of which may be controlled. Controlling this phase difference to be π/2 allows the direction of motion of the vibrating surface to be deduced.