All PICOSCALE products are based on a Michelson interferometer, a precise method to measure displacements and vibrations. The Michelson interferometer consists of a wavelength-stabilized laser, a beam splitter, a target and a reference mirror.
At the beam splitter, the light from the laser is divided into two arms. One arm is directed to the target surface while the other is directed to the reference mirror. After the light of both arms is reflected by the target surface and reference mirror, respectively, it travels back to the beam splitter. Here , both arms recombine and interference takes place.
The interference signal contains information on the displacement of the target surface with respect to the reference mirror.