At the seminar, consideration was given to advantages and drawbacks of methods for measuring coordinates of the laser beam center and determining the range and amount of laser beam displacements using the quadrant photoreceiver, CCD matrix, and dividing plates. 

It was shown that the quadrant photoreceiver method and the dividing plate method were most sensitive to displacements of a single-mode laser beam. The feasible accuracy of the CCD matrix method is 0.01µmwith a possibility of detecting linear displacements that is limited by the CCD matrix size.