Beam splitter for laser Doppler velocity measuring device - comprises optical cube displaced perpendicular to incident beam and rotated to determine partial beam intersection characteristics

The beam splitter uses an optical cube (2), onto which the incident laser beam (1) is directed at an angle of 45 deg. to one of its side faces. The cube is displaced perpendicular to the incident direction of the laser beam and is rotated to determine the point of intersection and the intersection angle of the two partial beams (1a, 1b). Pref. a glass plate (3) lies in the path of one of the partial beams (16) provided by the cube, with an adjustable angular position, ensuring the optimum overlap of the partial beams at the intersection point. ADVANTAGE - Provides measuring accuracy to within 0.1 per cent.