An apparatus and a method for profiling the intensity of a beam and thus measuring the overall intensity and power of a beam are disclosed that have particular use in stereolithography. A beam sensor comprising a pinhole in a plate and a photodetector behind the pinhole measures the intensity of portions...http://www.google.fr/patents/US5267013?utm_source=gb-gplus-shareBrevet US5267013 - Apparatus and method for profiling a beam
