The Agilent 10735A Three Axis Interferometer is used in multiple axis applications where linear and angular control of the stage is required. It combines in a single package the functionality of an optical bench with multiple beam benders, beam splitters, and three interferometers. The interferometers split an incoming laser beam into three beams to measure linear distance, pitch and yaw, or linear distance, roll and yaw. Three linear measurements provide the basis for calculating two angular measurements. The inherent beam parallelism ensures that there is essentially no cosine error between the three measurements and also ensures angle accuracy for pitch and yaw measurements.