HIGH-RESOLUTION KNIFE-EDGE LASER-BEAM PROFILING

A knife-edge method for profiling focused and unfocused laser beams wi th a high spatial resolution is presented. High resolution is achieved by dithering the knife-edge in the scan direction. The method is equi valent to the slit method but with a variable slit width also on a sub -mu m scale. A signal-to-noise ratio of 10(6): 1 has been demonstrated . The design is nearly as simple and of low-cost as that of the conven tional knife-edge method. The inversion algorithm used for obtaining t he beam profiles from knife-edge data is discussed. An excellent agree ment is found between measured and calculated beam profiles. The accur acy of this method is demonstrated also with beam propagation measurem ents.