LISA Technology Package laser modulator unit
The laser modulator unit (LMU) is the electro-optical part of the laser modulator (LM). It contains an acousto-optical modulator that introduces the heterodyne shift of the laser beams used in the optical interferometer metrology and modulates the beam powers. In addition, it continuously compensates for length variations in the optical fibres carrying the laser beams with an optical pathlength actuator.
This LISA Technology Package unit is provided by RUAG, Switzerland.