Is a device that is used to modulate the phase of a laser beam. It works by using an electro-optic crystal to change the optical path of the laser beam. The crystal is placed in the path of the laser beam and is controlled by an electrical signal. When the electrical signal is applied, the refractive index of the crystal changes, which causes the phase of the laser beam to be modulated. This process allows for the generation of modulated laser beams and the control of the phase of the laser that can be used in a variety of applications such as Interferometers and coherent beam combining.
